Merge from V6_main 15/03/2013

[modules/med.git] / src / MEDCoupling / MEDCouplingUMesh.cxx

// Copyright (C) 2007-2012  CEA/DEN, EDF R&D
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
//
// See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
//
// Author : Anthony Geay (CEA/DEN)

#include "MEDCouplingUMesh.hxx"
#include "MEDCouplingMemArray.txx"
#include "MEDCouplingFieldDouble.hxx"
#include "CellModel.hxx"
#include "VolSurfUser.txx"
#include "InterpolationUtils.hxx"
#include "PointLocatorAlgos.txx"
#include "BBTree.txx"
#include "SplitterTetra.hxx"
#include "DirectedBoundingBox.hxx"
#include "InterpKernelMeshQuality.hxx"
#include "InterpKernelCellSimplify.hxx"
#include "InterpKernelGeo2DEdgeArcCircle.hxx"
#include "MEDCouplingAutoRefCountObjectPtr.hxx"
#include "InterpKernelAutoPtr.hxx"
#include "InterpKernelGeo2DNode.hxx"
#include "InterpKernelGeo2DEdgeLin.hxx"
#include "InterpKernelGeo2DEdgeArcCircle.hxx"
#include "InterpKernelGeo2DQuadraticPolygon.hxx"

#include <sstream>
#include <fstream>
#include <numeric>
#include <cstring>
#include <limits>
#include <list>

using namespace ParaMEDMEM;

double MEDCouplingUMesh::EPS_FOR_POLYH_ORIENTATION=1.e-14;

const INTERP_KERNEL::NormalizedCellType MEDCouplingUMesh::MEDMEM_ORDER[N_MEDMEM_ORDER] = { INTERP_KERNEL::NORM_POINT1, INTERP_KERNEL::NORM_SEG2, INTERP_KERNEL::NORM_SEG3, INTERP_KERNEL::NORM_SEG4, INTERP_KERNEL::NORM_POLYL, INTERP_KERNEL::NORM_TRI3, INTERP_KERNEL::NORM_QUAD4, INTERP_KERNEL::NORM_TRI6, INTERP_KERNEL::NORM_TRI7, INTERP_KERNEL::NORM_QUAD8, INTERP_KERNEL::NORM_QUAD9, INTERP_KERNEL::NORM_POLYGON, INTERP_KERNEL::NORM_QPOLYG, INTERP_KERNEL::NORM_TETRA4, INTERP_KERNEL::NORM_PYRA5, INTERP_KERNEL::NORM_PENTA6, INTERP_KERNEL::NORM_HEXA8, INTERP_KERNEL::NORM_HEXGP12, INTERP_KERNEL::NORM_TETRA10, INTERP_KERNEL::NORM_PYRA13, INTERP_KERNEL::NORM_PENTA15, INTERP_KERNEL::NORM_HEXA20, INTERP_KERNEL::NORM_HEXA27, INTERP_KERNEL::NORM_POLYHED };

MEDCouplingUMesh *MEDCouplingUMesh::New()
{
  return new MEDCouplingUMesh;
}

MEDCouplingUMesh *MEDCouplingUMesh::New(const char *meshName, int meshDim)
{
  MEDCouplingUMesh *ret=new MEDCouplingUMesh;
  ret->setName(meshName);
  ret->setMeshDimension(meshDim);
  return ret;
}

MEDCouplingMesh *MEDCouplingUMesh::deepCpy() const
{
  return clone(true);
}

MEDCouplingUMesh *MEDCouplingUMesh::clone(bool recDeepCpy) const
{
  return new MEDCouplingUMesh(*this,recDeepCpy);
}

std::size_t MEDCouplingUMesh::getHeapMemorySize() const
{
  std::size_t ret=0;
  if(_nodal_connec)
    ret+=_nodal_connec->getHeapMemorySize();
  if(_nodal_connec_index)
    ret+=_nodal_connec_index->getHeapMemorySize();
  return MEDCouplingPointSet::getHeapMemorySize()+ret;
}

void MEDCouplingUMesh::updateTime() const
{
  MEDCouplingPointSet::updateTime();
  if(_nodal_connec)
    {
      updateTimeWith(*_nodal_connec);
    }
  if(_nodal_connec_index)
    {
      updateTimeWith(*_nodal_connec_index);
    }
}

MEDCouplingUMesh::MEDCouplingUMesh():_mesh_dim(-2),_nodal_connec(0),_nodal_connec_index(0)
{
}

/*!
 * This method checks that this is correctly designed. For example le coordinates are set, nodal connectivity.
 * When this method returns without throwing any exception, 'this' is expected to be writable, exchangeable and to be 
 * available for most of algorithm. When a mesh has been constructed from scratch it is a good habits to call this method to check
 * that all is in order in 'this'.
 */
void MEDCouplingUMesh::checkCoherency() const throw(INTERP_KERNEL::Exception)
{
  if(_mesh_dim<-1)
   throw INTERP_KERNEL::Exception("No mesh dimension specified !");
  if(_mesh_dim!=-1)
    MEDCouplingPointSet::checkCoherency();
  for(std::set<INTERP_KERNEL::NormalizedCellType>::const_iterator iter=_types.begin();iter!=_types.end();iter++)
    {
      if((int)INTERP_KERNEL::CellModel::GetCellModel(*iter).getDimension()!=_mesh_dim)
        {
          std::ostringstream message;
          message << "Mesh invalid because dimension is " << _mesh_dim << " and there is presence of cell(s) with type " << (*iter);
          throw INTERP_KERNEL::Exception(message.str().c_str());
        }
    }
  if(_nodal_connec)
    {
      if(_nodal_connec->getNumberOfComponents()!=1)
        throw INTERP_KERNEL::Exception("Nodal connectivity array is expected to be with number of components set to one !");
      if(_nodal_connec->getInfoOnComponent(0)!="")
        throw INTERP_KERNEL::Exception("Nodal connectivity array is expected to have no info on its single component !");
    }
  if(_nodal_connec_index)
    {
      if(_nodal_connec_index->getNumberOfComponents()!=1)
        throw INTERP_KERNEL::Exception("Nodal connectivity index array is expected to be with number of components set to one !");
      if(_nodal_connec_index->getInfoOnComponent(0)!="")
        throw INTERP_KERNEL::Exception("Nodal connectivity index array is expected to have no info on its single component !");
    }
}

/*!
 * This method performs deeper checking in 'this' than MEDCouplingUMesh::checkCoherency does.
 * So this method is more time-consuming. This method checks that nodal connectivity points to valid node ids.
 * No geometrical aspects are checked here. These aspects are done in MEDCouplingUMesh::checkCoherency2.
 */
void MEDCouplingUMesh::checkCoherency1(double eps) const throw(INTERP_KERNEL::Exception)
{
  checkCoherency();
  if(_mesh_dim==-1)
    return ;
  int meshDim=getMeshDimension();
  int nbOfNodes=getNumberOfNodes();
  int nbOfCells=getNumberOfCells();
  const int *ptr=_nodal_connec->getConstPointer();
  const int *ptrI=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)ptr[ptrI[i]]);
      if((int)cm.getDimension()!=meshDim)
        {
          std::ostringstream oss;
          oss << "MEDCouplingUMesh::checkCoherency1 : cell << #" << i<< " with type Type " << cm.getRepr() << " in 'this' whereas meshdim == " << meshDim << " !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
      int nbOfNodesInCell=ptrI[i+1]-ptrI[i]-1;
      if(!cm.isDynamic())
        if(nbOfNodesInCell!=(int)cm.getNumberOfNodes())
          {
            std::ostringstream oss;
            oss << "MEDCouplingUMesh::checkCoherency1 : cell #" << i << " with static Type '" << cm.getRepr() << "' has " <<  cm.getNumberOfNodes();
            oss << " nodes whereas in connectivity there is " << nbOfNodesInCell << " nodes ! Looks very bad !";
            throw INTERP_KERNEL::Exception(oss.str().c_str());
          }
      for(const int *w=ptr+ptrI[i]+1;w!=ptr+ptrI[i+1];w++)
        {
          int nodeId=*w;
          if(nodeId>=0)
            {
              if(nodeId>=nbOfNodes)
                {
                  std::ostringstream oss; oss << "Cell #" << i << " is consituted of node #" << nodeId << " whereas there are only " << nbOfNodes << " nodes !";
                  throw INTERP_KERNEL::Exception(oss.str().c_str());
                }
            }
          else if(nodeId<-1)
            {
              std::ostringstream oss; oss << "Cell #" << i << " is consituted of node #" << nodeId << " in connectivity ! sounds bad !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
          else
            {
              if((INTERP_KERNEL::NormalizedCellType)(ptr[ptrI[i]])!=INTERP_KERNEL::NORM_POLYHED)
                {
                  std::ostringstream oss; oss << "Cell #" << i << " is consituted of node #-1 in connectivity ! sounds bad !";
                  throw INTERP_KERNEL::Exception(oss.str().c_str());
                }
            }
        }
    }
}

void MEDCouplingUMesh::checkCoherency2(double eps) const throw(INTERP_KERNEL::Exception)
{
  checkCoherency1(eps);
}

void MEDCouplingUMesh::setMeshDimension(int meshDim)
{
  if(meshDim<-1)
    throw INTERP_KERNEL::Exception("Invalid meshDim specified ! Must be greater or equal to -1 !");
  _mesh_dim=meshDim;
  declareAsNew();
}

void MEDCouplingUMesh::allocateCells(int nbOfCells)
{
  if(_nodal_connec_index)
    {
      _nodal_connec_index->decrRef();
    }
  if(_nodal_connec)
    {
      _nodal_connec->decrRef();
    }
  _nodal_connec_index=DataArrayInt::New();
  _nodal_connec_index->reserve(nbOfCells+1);
  _nodal_connec_index->pushBackSilent(0);
  _nodal_connec=DataArrayInt::New();
  _nodal_connec->reserve(2*nbOfCells);
  _types.clear();
  declareAsNew();
}

/*!
 * Appends a cell in connectivity array.
 * @param type type of cell to add.
 * @param size number of nodes constituting this cell.
 * @param nodalConnOfCell the connectivity of the cell to add.
 */
void MEDCouplingUMesh::insertNextCell(INTERP_KERNEL::NormalizedCellType type, int size, const int *nodalConnOfCell) throw(INTERP_KERNEL::Exception)
{
  const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
  if(_nodal_connec_index==0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::insertNextCell : nodal connectivity not set ! invoke allocateCells before calling insertNextCell !");
  if((int)cm.getDimension()==_mesh_dim)
    {
      if(!cm.isDynamic())
        if(size!=(int)cm.getNumberOfNodes())
          {
            std::ostringstream oss; oss << "MEDCouplingUMesh::insertNextCell : Trying to push a " << cm.getRepr() << " cell with a size of " << size;
            oss << " ! Expecting " << cm.getNumberOfNodes() << " !";
            throw INTERP_KERNEL::Exception(oss.str().c_str());
          }
      int idx=_nodal_connec_index->back();
      int val=idx+size+1;
      _nodal_connec_index->pushBackSilent(val);
      _nodal_connec->writeOnPlace(idx,type,nodalConnOfCell,size);
      _types.insert(type);
    }
  else
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::insertNextCell : cell type " << cm.getRepr() << " has a dimension " << cm.getDimension();
      oss << " whereas Mesh Dimension of current UMesh instance is set to " << _mesh_dim << " ! Please invoke \"setMeshDimension\" method before or invoke ";
      oss << "\"MEDCouplingUMesh::New\" static method with 2 parameters name and meshDimension !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
}

/*!
 * Method to be called to cloture the insertion of cells using this->insertNextCell.
 */
void MEDCouplingUMesh::finishInsertingCells()
{
  _nodal_connec->pack();
  _nodal_connec_index->pack();
  _nodal_connec->declareAsNew();
  _nodal_connec_index->declareAsNew();
  updateTime();
}

/*!
 * Entry point for iteration over cells of this. Warning the returned cell iterator should be deallocated.
 * Useful for python users.
 */
MEDCouplingUMeshCellIterator *MEDCouplingUMesh::cellIterator()
{
  return new MEDCouplingUMeshCellIterator(this);
}

/*!
 * Entry point for iteration over cells groups geo types per geotypes. Warning the returned cell iterator should be deallocated.
 * If 'this' is not so that that cells are grouped by geo types this method will throw an exception.
 * In this case MEDCouplingUMesh::sortCellsInMEDFileFrmt or MEDCouplingUMesh::rearrange2ConsecutiveCellTypes methods for example can be called before invoking this method.
 * Useful for python users.
 */
MEDCouplingUMeshCellByTypeEntry *MEDCouplingUMesh::cellsByType() throw(INTERP_KERNEL::Exception)
{
  if(!checkConsecutiveCellTypes())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::cellsByType : this mesh is not sorted by type !");
  return new MEDCouplingUMeshCellByTypeEntry(this);
}

std::set<INTERP_KERNEL::NormalizedCellType> MEDCouplingUMesh::getAllGeoTypes() const
{
  return _types;
}

/*!
 * This method is a method that compares 'this' and 'other'.
 * This method compares \b all attributes, even names and component names.
 */
bool MEDCouplingUMesh::isEqualIfNotWhy(const MEDCouplingMesh *other, double prec, std::string& reason) const throw(INTERP_KERNEL::Exception)
{
  if(!other)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::isEqualIfNotWhy : input other pointer is null !");
  std::ostringstream oss; oss.precision(15);
  const MEDCouplingUMesh *otherC=dynamic_cast<const MEDCouplingUMesh *>(other);
  if(!otherC)
    {
      reason="mesh given in input is not castable in MEDCouplingUMesh !";
      return false;
    }
  if(!MEDCouplingPointSet::isEqualIfNotWhy(other,prec,reason))
    return false;
  if(_mesh_dim!=otherC->_mesh_dim)
    {
      oss << "umesh dimension mismatch : this mesh dimension=" << _mesh_dim << " other mesh dimension=" <<  otherC->_mesh_dim;
      reason=oss.str();
      return false;
    }
  if(_types!=otherC->_types)
    {
      oss << "umesh geometric type mismatch :\nThis geometric types are :";
      for(std::set<INTERP_KERNEL::NormalizedCellType>::const_iterator iter=_types.begin();iter!=_types.end();iter++)
        { const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(*iter); oss << cm.getRepr() << ", "; }
      oss << "\nOther geometric types are :";
      for(std::set<INTERP_KERNEL::NormalizedCellType>::const_iterator iter=otherC->_types.begin();iter!=otherC->_types.end();iter++)
        { const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(*iter); oss << cm.getRepr() << ", "; }
      reason=oss.str();
      return false;
    }
  if(_nodal_connec!=0 || otherC->_nodal_connec!=0)
    if(_nodal_connec==0 || otherC->_nodal_connec==0)
      {
        reason="Only one UMesh between the two this and other has its nodal connectivity DataArrayInt defined !";
        return false;
      }
  if(_nodal_connec!=otherC->_nodal_connec)
    if(!_nodal_connec->isEqualIfNotWhy(*otherC->_nodal_connec,reason))
      {
        reason.insert(0,"Nodal connectivity DataArrayInt differ : ");
        return false;
      }
  if(_nodal_connec_index!=0 || otherC->_nodal_connec_index!=0)
    if(_nodal_connec_index==0 || otherC->_nodal_connec_index==0)
      {
        reason="Only one UMesh between the two this and other has its nodal connectivity index DataArrayInt defined !";
        return false;
      }
  if(_nodal_connec_index!=otherC->_nodal_connec_index)
    if(!_nodal_connec_index->isEqualIfNotWhy(*otherC->_nodal_connec_index,reason))
      {
        reason.insert(0,"Nodal connectivity index DataArrayInt differ : ");
        return false;
      }
  return true;
}

bool MEDCouplingUMesh::isEqualWithoutConsideringStr(const MEDCouplingMesh *other, double prec) const
{
  const MEDCouplingUMesh *otherC=dynamic_cast<const MEDCouplingUMesh *>(other);
  if(!otherC)
    return false;
  if(!MEDCouplingPointSet::isEqualWithoutConsideringStr(other,prec))
    return false;
  if(_mesh_dim!=otherC->_mesh_dim)
    return false;
  if(_types!=otherC->_types)
    return false;
  if(_nodal_connec!=0 || otherC->_nodal_connec!=0)
    if(_nodal_connec==0 || otherC->_nodal_connec==0)
      return false;
  if(_nodal_connec!=otherC->_nodal_connec)
    if(!_nodal_connec->isEqualWithoutConsideringStr(*otherC->_nodal_connec))
      return false;
  if(_nodal_connec_index!=0 || otherC->_nodal_connec_index!=0)
    if(_nodal_connec_index==0 || otherC->_nodal_connec_index==0)
      return false;
  if(_nodal_connec_index!=otherC->_nodal_connec_index)
    if(!_nodal_connec_index->isEqualWithoutConsideringStr(*otherC->_nodal_connec_index))
      return false;
  return true;
}

/*!
 * This method looks if 'this' and 'other' are geometrically equivalent that is to say if each cell in 'other' correspond to one cell and only one
 * in 'this' is found regarding 'prec' parameter and 'cellCompPol' parameter.
 * 
 * In case of success cellCor and nodeCor are informed both. 
 * @param cellCompPol values are described in MEDCouplingUMesh::zipConnectivityTraducer method.
 * @param cellCor output array giving the correspondance of cells from 'other' to 'this'.
 * @param nodeCor output array giving the correspondance of nodes from 'other' to 'this'.
 */
void MEDCouplingUMesh::checkDeepEquivalWith(const MEDCouplingMesh *other, int cellCompPol, double prec,
                                            DataArrayInt *&cellCor, DataArrayInt *&nodeCor) const throw(INTERP_KERNEL::Exception)
{
  const MEDCouplingUMesh *otherC=dynamic_cast<const MEDCouplingUMesh *>(other);
  if(!otherC)
    throw INTERP_KERNEL::Exception("checkDeepEquivalWith : Two meshes are not not unstructured !");
  MEDCouplingMesh::checkFastEquivalWith(other,prec);
  if(_types!=otherC->_types)
    throw INTERP_KERNEL::Exception("checkDeepEquivalWith : Types are not equal !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m=MergeUMeshes(this,otherC);
  bool areNodesMerged;
  int newNbOfNodes;
  int oldNbOfNodes=getNumberOfNodes();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> da=m->buildPermArrayForMergeNode(prec,oldNbOfNodes,areNodesMerged,newNbOfNodes);
  //mergeNodes
  if(!areNodesMerged)
    throw INTERP_KERNEL::Exception("checkDeepEquivalWith : Nodes are incompatible ! ");
  const int *pt=std::find_if(da->getConstPointer()+oldNbOfNodes,da->getConstPointer()+da->getNbOfElems(),std::bind2nd(std::greater<int>(),oldNbOfNodes-1));
  if(pt!=da->getConstPointer()+da->getNbOfElems())
    throw INTERP_KERNEL::Exception("checkDeepEquivalWith : some nodes in other are not in this !");
  m->renumberNodes(da->getConstPointer(),newNbOfNodes);
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> nodeCor2=da->substr(oldNbOfNodes);
  da=m->mergeNodes(prec,areNodesMerged,newNbOfNodes);
  
  //
  da=m->zipConnectivityTraducer(cellCompPol);
  int maxId=*std::max_element(da->getConstPointer(),da->getConstPointer()+getNumberOfCells());
  pt=std::find_if(da->getConstPointer()+getNumberOfCells(),da->getConstPointer()+da->getNbOfElems(),std::bind2nd(std::greater<int>(),maxId));
  if(pt!=da->getConstPointer()+da->getNbOfElems())
    throw INTERP_KERNEL::Exception("checkDeepEquivalWith : some cells in other are not in this !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellCor2=da->selectByTupleId2(getNumberOfCells(),da->getNbOfElems(),1);
  nodeCor=nodeCor2->isIdentity()?0:nodeCor2.retn();
  cellCor=cellCor2->isIdentity()?0:cellCor2.retn();
}

/*!
 * This method looks if 'this' and 'other' are geometrically equivalent that is to say if each cell in 'other' correspond to one cell and only one
 * in 'this' is found regarding 'prec' parameter and 'cellCompPol' parameter. The difference with MEDCouplingUMesh::checkDeepEquivalWith method is that
 * coordinates of 'this' and 'other' are expected to be the same. If not an exception will be thrown.
 * This method is close to MEDCouplingUMesh::areCellsIncludedIn except that this method throws exception !
 * 
 * In case of success cellCor are informed both. 
 * @param cellCompPol values are described in MEDCouplingUMesh::zipConnectivityTraducer method.
 * @param cellCor output array giving the correspondance of cells from 'other' to 'this'.
 */
void MEDCouplingUMesh::checkDeepEquivalOnSameNodesWith(const MEDCouplingMesh *other, int cellCompPol, double prec,
                                                       DataArrayInt *&cellCor) const throw(INTERP_KERNEL::Exception)
{
  const MEDCouplingUMesh *otherC=dynamic_cast<const MEDCouplingUMesh *>(other);
  if(!otherC)
    throw INTERP_KERNEL::Exception("checkDeepEquivalOnSameNodesWith : Two meshes are not not unstructured !");
  MEDCouplingMesh::checkFastEquivalWith(other,prec);
  if(_types!=otherC->_types)
    throw INTERP_KERNEL::Exception("checkDeepEquivalOnSameNodesWith : Types are not equal !");
  if(_coords!=otherC->_coords)
    throw INTERP_KERNEL::Exception("checkDeepEquivalOnSameNodesWith : meshes do not share the same coordinates ! Use tryToShareSameCoordinates or call checkDeepEquivalWith !");
  std::vector<const MEDCouplingUMesh *> ms(2);
  ms[0]=this;
  ms[1]=otherC;
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m=MergeUMeshesOnSameCoords(ms);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> da=m->zipConnectivityTraducer(cellCompPol);
  int maxId=*std::max_element(da->getConstPointer(),da->getConstPointer()+getNumberOfCells());
  const int *pt=std::find_if(da->getConstPointer()+getNumberOfCells(),da->getConstPointer()+da->getNbOfElems(),std::bind2nd(std::greater<int>(),maxId));
  if(pt!=da->getConstPointer()+da->getNbOfElems())
    {
      throw INTERP_KERNEL::Exception("checkDeepEquivalOnSameNodesWith : some cells in other are not in this !");
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellCor2=da->selectByTupleId2(getNumberOfCells(),da->getNbOfElems(),1);
  cellCor=cellCor2->isIdentity()?0:cellCor2.retn();
}

/*!
 * This method checks fastly that 'this' and 'other' are equal. 
 */
void MEDCouplingUMesh::checkFastEquivalWith(const MEDCouplingMesh *other, double prec) const throw(INTERP_KERNEL::Exception)
{
  const MEDCouplingUMesh *otherC=dynamic_cast<const MEDCouplingUMesh *>(other);
  if(!otherC)
    throw INTERP_KERNEL::Exception("checkFastEquivalWith : Two meshes are not not unstructured !");
  MEDCouplingPointSet::checkFastEquivalWith(other,prec);
  int nbOfCells=getNumberOfCells();
  if(nbOfCells<1)
    return ;
  bool status=true;
  status&=areCellsFrom2MeshEqual(otherC,0,prec);
  status&=areCellsFrom2MeshEqual(otherC,nbOfCells/2,prec);
  status&=areCellsFrom2MeshEqual(otherC,nbOfCells-1,prec);
  if(!status)
    throw INTERP_KERNEL::Exception("checkFastEquivalWith : Two meshes are not equal because on 3 test cells some difference have been detected !");
}

/*!
 * \b WARNING this method do the assumption that connectivity lies on the coordinates set.
 * For speed reasons no check of this will be done.
 */
void MEDCouplingUMesh::getReverseNodalConnectivity(DataArrayInt *revNodal, DataArrayInt *revNodalIndx) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  int nbOfNodes=getNumberOfNodes();
  int *revNodalIndxPtr=new int[nbOfNodes+1];
  revNodalIndx->useArray(revNodalIndxPtr,true,CPP_DEALLOC,nbOfNodes+1,1);
  std::fill(revNodalIndxPtr,revNodalIndxPtr+nbOfNodes+1,0);
  const int *conn=_nodal_connec->getConstPointer();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  int nbOfEltsInRevNodal=0;
  for(int eltId=0;eltId<nbOfCells;eltId++)
    {
      const int *strtNdlConnOfCurCell=conn+connIndex[eltId]+1;
      const int *endNdlConnOfCurCell=conn+connIndex[eltId+1];
      for(const int *iter=strtNdlConnOfCurCell;iter!=endNdlConnOfCurCell;iter++)
        if(*iter>=0)//for polyhedrons
          {
            nbOfEltsInRevNodal++;
            revNodalIndxPtr[(*iter)+1]++;
          }
    }
  std::transform(revNodalIndxPtr+1,revNodalIndxPtr+nbOfNodes+1,revNodalIndxPtr,revNodalIndxPtr+1,std::plus<int>());
  int *revNodalPtr=new int[nbOfEltsInRevNodal];
  revNodal->useArray(revNodalPtr,true,CPP_DEALLOC,nbOfEltsInRevNodal,1);
  std::fill(revNodalPtr,revNodalPtr+nbOfEltsInRevNodal,-1);
  for(int eltId=0;eltId<nbOfCells;eltId++)
    {
      const int *strtNdlConnOfCurCell=conn+connIndex[eltId]+1;
      const int *endNdlConnOfCurCell=conn+connIndex[eltId+1];
      for(const int *iter=strtNdlConnOfCurCell;iter!=endNdlConnOfCurCell;iter++)
        if(*iter>=0)//for polyhedrons
          *std::find_if(revNodalPtr+revNodalIndxPtr[*iter],revNodalPtr+revNodalIndxPtr[*iter+1],std::bind2nd(std::equal_to<int>(),-1))=eltId;
    }
}

/// @cond INTERNAL

int MEDCouplingFastNbrer(int id, unsigned nb, const INTERP_KERNEL::CellModel& cm, bool compute, const int *conn1, const int *conn2)
{
  return id;
}

int MEDCouplingOrientationSensitiveNbrer(int id, unsigned nb, const INTERP_KERNEL::CellModel& cm, bool compute, const int *conn1, const int *conn2)
{
  if(!compute)
    return id+1;
  else
    {
      if(cm.getOrientationStatus(nb,conn1,conn2))
        return id+1;
      else
        return -(id+1);
    }
}

class MinusOneSonsGenerator
{
public:
  MinusOneSonsGenerator(const INTERP_KERNEL::CellModel& cm):_cm(cm) { }
  unsigned getNumberOfSons2(const int *conn, int lgth) const { return _cm.getNumberOfSons2(conn,lgth); }
  unsigned fillSonCellNodalConnectivity2(int sonId, const int *nodalConn, int lgth, int *sonNodalConn, INTERP_KERNEL::NormalizedCellType& typeOfSon) const { return _cm.fillSonCellNodalConnectivity2(sonId,nodalConn,lgth,sonNodalConn,typeOfSon); }
  static const int DELTA=1;
private:
  const INTERP_KERNEL::CellModel& _cm;
};

class MinusOneSonsGeneratorBiQuadratic
{
public:
  MinusOneSonsGeneratorBiQuadratic(const INTERP_KERNEL::CellModel& cm):_cm(cm) { }
  unsigned getNumberOfSons2(const int *conn, int lgth) const { return _cm.getNumberOfSons2(conn,lgth); }
  unsigned fillSonCellNodalConnectivity2(int sonId, const int *nodalConn, int lgth, int *sonNodalConn, INTERP_KERNEL::NormalizedCellType& typeOfSon) const { return _cm.fillSonCellNodalConnectivity4(sonId,nodalConn,lgth,sonNodalConn,typeOfSon); }
  static const int DELTA=1;
private:
  const INTERP_KERNEL::CellModel& _cm;
};

class MinusTwoSonsGenerator
{
public:
  MinusTwoSonsGenerator(const INTERP_KERNEL::CellModel& cm):_cm(cm) { }
  unsigned getNumberOfSons2(const int *conn, int lgth) const { return _cm.getNumberOfEdgesIn3D(conn,lgth); }
  unsigned fillSonCellNodalConnectivity2(int sonId, const int *nodalConn, int lgth, int *sonNodalConn, INTERP_KERNEL::NormalizedCellType& typeOfSon) const { return _cm.fillSonEdgesNodalConnectivity3D(sonId,nodalConn,lgth,sonNodalConn,typeOfSon); }
  static const int DELTA=2;
private:
  const INTERP_KERNEL::CellModel& _cm;
};

/// @endcond

/*!
 * \b WARNING this method do the assumption that connectivity lies on the coordinates set.
 * For speed reasons no check of this will be done.
 * Given 'this' with spacedim equal to s and meshdim equal to p, this method returns a new allocated mesh
 * lying on the same coordinates than 'this' and having a meshdim equal to p-1.
 * The algorithm to compute this p-1 mesh is the following :
 * For each cell in 'this' it splits into p-1 elements.
 *   If this p-1 element does not already exists it is appended to the returned mesh
 *   If this p-1 element already exists, it is not appended.
 * This method returns or 4 arrays plus the returned mesh.
 * 'desc' and 'descIndx' are the descending connectivity. These 2 arrays tell for each cell in 'this', to wich p-1 dimension cell in returned mesh it refers.
 * For a cell with a cellid c in 'this' it is constituted of cells in [desc+descIndx[c],desc+descIndex[c+1])
 *
 * Reversely 'revDesc' and 'revDescIndx' are the reverse descending connectivity. These 2 arrays tell for each cell in returned mesh, to wich cell in 'this' it refers.
 * For a cell with a cellid d in returned p-1 mesh it is shared by the following cells in 'this' [revDesc+revDescIndx[d],revDesc+revDescIndx[d+1])
 *
 * \warning This method returns a mesh whose geometric type order in are \b not sorted.
 * In view of the MED file writing, a renumbering of cells in returned mesh (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildDescendingConnectivity(DataArrayInt *desc, DataArrayInt *descIndx, DataArrayInt *revDesc, DataArrayInt *revDescIndx) const throw(INTERP_KERNEL::Exception)
{
  return buildDescendingConnectivityGen<MinusOneSonsGenerator>(desc,descIndx,revDesc,revDescIndx,MEDCouplingFastNbrer);
}

/*!
 * \a this has to have a mesh dimension equal to 3. If it is not the case an INTERP_KERNEL::Exception will be thrown.
 * This behaves exactly as MEDCouplingUMesh::buildDescendingConnectivity does except that this method compute directly the transition from mesh dimension 3 to sub edges (dimension 1)
 * in one shot. That is to say that this method is equivalent to 2 successive calls to MEDCouplingUMesh::buildDescendingConnectivity.
 * This method returns 4 arrays and a mesh as MEDCouplingUMesh::buildDescendingConnectivity does.
 * \sa MEDCouplingUMesh::buildDescendingConnectivity
 */
MEDCouplingUMesh *MEDCouplingUMesh::explode3DMeshTo1D(DataArrayInt *desc, DataArrayInt *descIndx, DataArrayInt *revDesc, DataArrayInt *revDescIndx) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::explode3DMeshTo1D : This has to have a mesh dimension to 3 !");
  return buildDescendingConnectivityGen<MinusTwoSonsGenerator>(desc,descIndx,revDesc,revDescIndx,MEDCouplingFastNbrer);
}

/*!
 * WARNING this method do the assumption that connectivity lies on the coordinates set.
 * For speed reasons no check of this will be done.
 * This method differs from MEDCouplingUMesh::buildDescendingConnectivity method in that 'desc' is in different format.
 * This method is more precise because it returns in descending connectivity giving the direction. If value is positive the n-1 dim element is taken in the same direction,
 * if it is in the opposite direction it is retrieved negative. So the problem is for elemt #0 in C convention. That's why this method is the only one that retrieves 
 * an array in relative "FORTRAN" mode.
 *
 * \warning This method returns a mesh whose geometric type order in are \b not sorted.
 * In view of the MED file writing, a renumbering of cells in returned mesh (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildDescendingConnectivity2(DataArrayInt *desc, DataArrayInt *descIndx, DataArrayInt *revDesc, DataArrayInt *revDescIndx) const throw(INTERP_KERNEL::Exception)
{
  return buildDescendingConnectivityGen<MinusOneSonsGenerator>(desc,descIndx,revDesc,revDescIndx,MEDCouplingOrientationSensitiveNbrer);
}

/*!
 * \b WARNING this method do the assumption that connectivity lies on the coordinates set.
 * For speed reasons no check of this will be done. This method calls MEDCouplingUMesh::buildDescendingConnectivity to compute the result.
 * This method lists cell by cell in \b this which are its neighbors. To compute the result only connectivities are considered.
 * The a cell with id 'cellId' its neighbors are neighbors[neighborsIndx[cellId]:neighborsIndx[cellId+1]].
 *
 * \param [out] neighbors is an array storing all the neighbors of all cells in \b this. This array is newly allocated and should be dealt by the caller. \b neighborsIndx 2nd output
 *                        parameter allows to select the right part in this array. The number of tuples is equal to the last values in \b neighborsIndx.
 * \param [out] neighborsIndx is an array of size this->getNumberOfCells()+1 newly allocated and should be dealt by the caller. This arrays allow to use the first output parameter \b neighbors.
 */
void MEDCouplingUMesh::computeNeighborsOfCells(DataArrayInt *&neighbors, DataArrayInt *&neighborsIndx) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descIndx=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> meshDM1=buildDescendingConnectivity(desc,descIndx,revDesc,revDescIndx);
  meshDM1=0;
  ComputeNeighborsOfCellsAdv(desc,descIndx,revDesc,revDescIndx,neighbors,neighborsIndx);
}

/*!
 * This method is called by MEDCouplingUMesh::computeNeighborsOfCells. This methods performs the algorithm of MEDCouplingUMesh::computeNeighborsOfCells.
 * This method is useful for users that want to reduce along a criterion the set of neighbours cell. This is typically the case to extract a set a neighbours,
 * excluding a set of meshdim-1 cells in input descending connectivity.
 * Typically \b desc, \b descIndx, \b revDesc and \b revDescIndx input params are the result of MEDCouplingUMesh::buildDescendingConnectivity.
 * This method lists cell by cell in \b this which are its neighbors. To compute the result only connectivities are considered.
 * The a cell with id 'cellId' its neighbors are neighbors[neighborsIndx[cellId]:neighborsIndx[cellId+1]].
 *
 * \param [in] desc descending connectivity array.
 * \param [in] descIndx descending connectivity index array used to walk through \b desc.
 * \param [in] revDesc reverse descending connectivity array.
 * \param [in] revDescIndx reverse descending connectivity index array used to walk through \b revDesc.
 * \param [out] neighbors is an array storing all the neighbors of all cells in \b this. This array is newly allocated and should be dealt by the caller. \b neighborsIndx 2nd output
 *                        parameter allows to select the right part in this array. The number of tuples is equal to the last values in \b neighborsIndx.
 * \param [out] neighborsIndx is an array of size this->getNumberOfCells()+1 newly allocated and should be dealt by the caller. This arrays allow to use the first output parameter \b neighbors.
 */
void MEDCouplingUMesh::ComputeNeighborsOfCellsAdv(const DataArrayInt *desc, const DataArrayInt *descIndx, const DataArrayInt *revDesc, const DataArrayInt *revDescIndx,
                                                  DataArrayInt *&neighbors, DataArrayInt *&neighborsIndx) throw(INTERP_KERNEL::Exception)
{
  if(!desc || !descIndx || !revDesc || !revDescIndx)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::ComputeNeighborsOfCellsAdv some input array is empty !");
  const int *descPtr=desc->getConstPointer();
  const int *descIPtr=descIndx->getConstPointer();
  const int *revDescPtr=revDesc->getConstPointer();
  const int *revDescIPtr=revDescIndx->getConstPointer();
  //
  int nbCells=descIndx->getNumberOfTuples()-1;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> out0=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> out1=DataArrayInt::New(); out1->alloc(nbCells+1,1);
  int *out1Ptr=out1->getPointer();
  *out1Ptr++=0;
  out0->reserve(desc->getNumberOfTuples());
  for(int i=0;i<nbCells;i++,descIPtr++,out1Ptr++)
    {
      for(const int *w1=descPtr+descIPtr[0];w1!=descPtr+descIPtr[1];w1++)
        {
          std::set<int> s(revDescPtr+revDescIPtr[*w1],revDescPtr+revDescIPtr[(*w1)+1]);
          s.erase(i);
          out0->insertAtTheEnd(s.begin(),s.end());
        }
      *out1Ptr=out0->getNumberOfTuples();
    }
  neighbors=out0.retn();
  neighborsIndx=out1.retn();
}

/// @cond INTERNAL

/*!
 * \b WARNING this method do the assumption that connectivity lies on the coordinates set.
 * For speed reasons no check of this will be done.
 */
template<class SonsGenerator>
MEDCouplingUMesh *MEDCouplingUMesh::buildDescendingConnectivityGen(DataArrayInt *desc, DataArrayInt *descIndx, DataArrayInt *revDesc, DataArrayInt *revDescIndx, DimM1DescNbrer nbrer) const throw(INTERP_KERNEL::Exception)
{
  if(!desc || !descIndx || !revDesc || !revDescIndx)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildDescendingConnectivityGen : present of a null pointer in input !");
  checkConnectivityFullyDefined();
  int nbOfCells=getNumberOfCells();
  int nbOfNodes=getNumberOfNodes();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revNodalIndx=DataArrayInt::New(); revNodalIndx->alloc(nbOfNodes+1,1); revNodalIndx->fillWithZero();
  int *revNodalIndxPtr=revNodalIndx->getPointer();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  std::string name="Mesh constituent of "; name+=getName();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New(name.c_str(),getMeshDimension()-SonsGenerator::DELTA);
  ret->setCoords(getCoords());
  ret->allocateCells(2*nbOfCells);
  descIndx->alloc(nbOfCells+1,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc2(DataArrayInt::New()); revDesc2->reserve(2*nbOfCells);
  int *descIndxPtr=descIndx->getPointer(); *descIndxPtr++=0;
  for(int eltId=0;eltId<nbOfCells;eltId++,descIndxPtr++)
    {
      int pos=connIndex[eltId];
      int posP1=connIndex[eltId+1];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[pos]);
      SonsGenerator sg(cm);
      unsigned nbOfSons=sg.getNumberOfSons2(conn+pos+1,posP1-pos-1);
      INTERP_KERNEL::AutoPtr<int> tmp=new int[posP1-pos];
      for(unsigned i=0;i<nbOfSons;i++)
        {
          INTERP_KERNEL::NormalizedCellType cmsId;
          unsigned nbOfNodesSon=sg.fillSonCellNodalConnectivity2(i,conn+pos+1,posP1-pos-1,tmp,cmsId);
          for(unsigned k=0;k<nbOfNodesSon;k++)
            if(tmp[k]>=0)
              revNodalIndxPtr[tmp[k]+1]++;
          ret->insertNextCell(cmsId,nbOfNodesSon,tmp);
          revDesc2->pushBackSilent(eltId);
        }
      descIndxPtr[0]=descIndxPtr[-1]+(int)nbOfSons;
    }
  int nbOfCellsM1=ret->getNumberOfCells();
  std::transform(revNodalIndxPtr+1,revNodalIndxPtr+nbOfNodes+1,revNodalIndxPtr,revNodalIndxPtr+1,std::plus<int>());
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revNodal=DataArrayInt::New(); revNodal->alloc(revNodalIndx->back(),1);
  std::fill(revNodal->getPointer(),revNodal->getPointer()+revNodalIndx->back(),-1);
  int *revNodalPtr=revNodal->getPointer();
  const int *connM1=ret->getNodalConnectivity()->getConstPointer();
  const int *connIndexM1=ret->getNodalConnectivityIndex()->getConstPointer();
  for(int eltId=0;eltId<nbOfCellsM1;eltId++)
    {
      const int *strtNdlConnOfCurCell=connM1+connIndexM1[eltId]+1;
      const int *endNdlConnOfCurCell=connM1+connIndexM1[eltId+1];
      for(const int *iter=strtNdlConnOfCurCell;iter!=endNdlConnOfCurCell;iter++)
        if(*iter>=0)//for polyhedrons
          *std::find_if(revNodalPtr+revNodalIndxPtr[*iter],revNodalPtr+revNodalIndxPtr[*iter+1],std::bind2nd(std::equal_to<int>(),-1))=eltId;
    }
  //
  DataArrayInt *commonCells=0,*commonCellsI=0;
  FindCommonCellsAlg(3,0,ret->getNodalConnectivity(),ret->getNodalConnectivityIndex(),revNodal,revNodalIndx,commonCells,commonCellsI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> commonCellsTmp(commonCells),commonCellsITmp(commonCellsI);
  const int *commonCellsPtr(commonCells->getConstPointer()),*commonCellsIPtr(commonCellsI->getConstPointer());
  int newNbOfCellsM1=-1;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> o2nM1=DataArrayInt::BuildOld2NewArrayFromSurjectiveFormat2(nbOfCellsM1,commonCells->begin(),
                                                                                                            commonCellsI->begin(),commonCellsI->end(),newNbOfCellsM1);
  std::vector<bool> isImpacted(nbOfCellsM1,false);
  for(const int *work=commonCellsI->begin();work!=commonCellsI->end()-1;work++)
    for(int work2=work[0];work2!=work[1];work2++)
      isImpacted[commonCellsPtr[work2]]=true;
  const int *o2nM1Ptr=o2nM1->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> n2oM1=o2nM1->invertArrayO2N2N2OBis(newNbOfCellsM1);
  const int *n2oM1Ptr=n2oM1->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret2=static_cast<MEDCouplingUMesh *>(ret->buildPartOfMySelf(n2oM1->begin(),n2oM1->end(),true));
  ret2->copyTinyInfoFrom(this);
  desc->alloc(descIndx->back(),1);
  int *descPtr=desc->getPointer();
  const INTERP_KERNEL::CellModel& cmsDft=INTERP_KERNEL::CellModel::GetCellModel(INTERP_KERNEL::NORM_POINT1);
  for(int i=0;i<nbOfCellsM1;i++,descPtr++)
    {
      if(!isImpacted[i])
        *descPtr=nbrer(o2nM1Ptr[i],0,cmsDft,false,0,0);
      else
        {
          if(i!=n2oM1Ptr[o2nM1Ptr[i]])
            {
              const INTERP_KERNEL::CellModel& cms=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)connM1[connIndexM1[i]]);
              *descPtr=nbrer(o2nM1Ptr[i],connIndexM1[i+1]-connIndexM1[i]-1,cms,true,connM1+connIndexM1[n2oM1Ptr[o2nM1Ptr[i]]]+1,connM1+connIndexM1[i]+1);
            }
          else
            *descPtr=nbrer(o2nM1Ptr[i],0,cmsDft,false,0,0);
        }
    }
  revDesc->reserve(newNbOfCellsM1);
  revDescIndx->alloc(newNbOfCellsM1+1,1);
  int *revDescIndxPtr=revDescIndx->getPointer(); *revDescIndxPtr++=0;
  const int *revDesc2Ptr=revDesc2->getConstPointer();
  for(int i=0;i<newNbOfCellsM1;i++,revDescIndxPtr++)
    {
      int oldCellIdM1=n2oM1Ptr[i];
      if(!isImpacted[oldCellIdM1])
        {
          revDesc->pushBackSilent(revDesc2Ptr[oldCellIdM1]);
          revDescIndxPtr[0]=revDescIndxPtr[-1]+1;
        }
      else
        {
          for(int j=commonCellsIPtr[0];j<commonCellsIPtr[1];j++)
            revDesc->pushBackSilent(revDesc2Ptr[commonCellsPtr[j]]);
          revDescIndxPtr[0]=revDescIndxPtr[-1]+commonCellsIPtr[1]-commonCellsIPtr[0];
          commonCellsIPtr++;
        }
    }
  //
  return ret2.retn();
}

struct MEDCouplingAccVisit
{
  MEDCouplingAccVisit():_new_nb_of_nodes(0) { }
  int operator()(int val) { if(val!=-1) return _new_nb_of_nodes++; else return -1; }
  int _new_nb_of_nodes;
};

/// @endcond


/*!
 * This method convert cell with ids in ['cellIdsToConvertBg','cellIdsToConvertEnd') into 'this' into dynamic types without changing geometry.
 * That is to say if 'this' is a 2D, mesh after the invocation of this method it will contain only polygons.
 * If 'this' is a 3D mesh after the invocation of this method it will contain only polyhedra.
 * If mesh dimension is not in [2,3] an exception is thrown.
 * Of course pay attention that the resulting mesh is slower than previous one.
 * If in ['cellIdsToConvertBg','cellIdsToConvertEnd') there is a cell id not in [0,'this->getNumberOfCells()') an exception will be thrown.
 * In this case if meshDim==2 the mesh is still valid and only cells treated before throw will be converted into polygon.
 * If mesh==3, after throw the mesh is \b unconsistent !
 * This method is above all designed to test more extensively algorithms able to deal with polygons/polyhedra.
 * 
 * \warning This method modifies can modify significantly the geometric type order in \a this.
 * In view of the MED file writing, a renumbering of cells in \a this (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
void MEDCouplingUMesh::convertToPolyTypes(const int *cellIdsToConvertBg, const int *cellIdsToConvertEnd)
{
  checkFullyDefined();
  int dim=getMeshDimension();
  if(dim<2 || dim>3)
    throw INTERP_KERNEL::Exception("Invalid mesh dimension : must be 2 or 3 !");
  int nbOfCells=getNumberOfCells();
  if(dim==2)
    {
      const int *connIndex=_nodal_connec_index->getConstPointer();
      int *conn=_nodal_connec->getPointer();
      for(const int *iter=cellIdsToConvertBg;iter!=cellIdsToConvertEnd;iter++)
        {
          if(*iter>=0 && *iter<nbOfCells)
            {
              const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[connIndex[*iter]]);
              if(!cm.isDynamic())
                conn[connIndex[*iter]]=INTERP_KERNEL::NORM_POLYGON;
              else
                conn[connIndex[*iter]]=INTERP_KERNEL::NORM_QPOLYG;
            }
          else
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::convertToPolyTypes : On rank #" << std::distance(cellIdsToConvertBg,iter) << " value is " << *iter << " which is not";
              oss << " in range [0," << nbOfCells << ") !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
    }
  else
    {
      int *connIndex=_nodal_connec_index->getPointer();
      int connIndexLgth=_nodal_connec_index->getNbOfElems();
      const int *connOld=_nodal_connec->getConstPointer();
      int connOldLgth=_nodal_connec->getNbOfElems();
      std::vector<int> connNew(connOld,connOld+connOldLgth);
      for(const int *iter=cellIdsToConvertBg;iter!=cellIdsToConvertEnd;iter++)
        {
          if(*iter>=0 && *iter<nbOfCells)
            {
              int pos=connIndex[*iter];
              int posP1=connIndex[(*iter)+1];
              int lgthOld=posP1-pos-1;
              const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)connNew[pos]);
              connNew[pos]=INTERP_KERNEL::NORM_POLYHED;
              unsigned nbOfFaces=cm.getNumberOfSons2(&connNew[pos+1],lgthOld);
              int *tmp=new int[nbOfFaces*lgthOld];
              int *work=tmp;
              for(int j=0;j<(int)nbOfFaces;j++)
                {
                  INTERP_KERNEL::NormalizedCellType type;
                  unsigned offset=cm.fillSonCellNodalConnectivity2(j,&connNew[pos+1],lgthOld,work,type);
                  work+=offset;
                  *work++=-1;
                }
              std::size_t newLgth=std::distance(tmp,work)-1;
              std::size_t delta=newLgth-lgthOld;
              std::transform(connIndex+(*iter)+1,connIndex+connIndexLgth,connIndex+(*iter)+1,std::bind2nd(std::plus<int>(),delta));
              connNew.insert(connNew.begin()+posP1,tmp+lgthOld,tmp+newLgth);
              std::copy(tmp,tmp+lgthOld,connNew.begin()+pos+1);
              delete [] tmp;
            }
          else
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::convertToPolyTypes : On rank #" << std::distance(cellIdsToConvertBg,iter) << " value is " << *iter << " which is not";
              oss << " in range [0," << nbOfCells << ") !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
      _nodal_connec->alloc((int)connNew.size(),1);
      int *newConnPtr=_nodal_connec->getPointer();
      std::copy(connNew.begin(),connNew.end(),newConnPtr);
    }
  computeTypes();
}

/*!
 * This method converts all cells into poly type if possible.
 * This method is purely for userfriendliness.
 * As this method can be costly in Memory, no optimization is done to avoid construction of useless vector.
 */
void MEDCouplingUMesh::convertAllToPoly()
{
  int nbOfCells=getNumberOfCells();
  std::vector<int> cellIds(nbOfCells);
  for(int i=0;i<nbOfCells;i++)
    cellIds[i]=i;
  convertToPolyTypes(&cellIds[0],&cellIds[0]+cellIds.size());
}

/*!
 * This method expects that 'this' has a spacedim equal to 3 and a mesh dimension equal to 3 too, if not an exception will be thrown.
 * This method work only on cells with type NORM_POLYHED, all other cells with different type, are remains unchanged.
 * For such polyhedra, they are expected to have only 1 face (containing 2 faces in opposition), having 2*n number of nodes (n nodes on
 * each 2 faces hidden in the single face of polyhedron).
 * The first face is expected to be right oriented because all faces of this polyhedron will be deduced.
 * When called 'this' is an invalid mesh on MED sense. This method will correct that for polyhedra.
 * In case of presence of polyhedron that has not the extruded aspect (2 faces with the same number of nodes) an exception is thrown and 'this'
 * remains unchanged.
 * This method is useful only for users that wants to build extruded unstructured mesh.
 * This method is a convenient one that avoids boring polyhedra setting during insertNextCell process.
 * In case of success, 'this' has be corrected contains the same number of cells and is valid in MED sense.
 */
void MEDCouplingUMesh::convertExtrudedPolyhedra() throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::convertExtrudedPolyhedra works on umeshes with meshdim equal to 3 and spaceDim equal to 3 too!");
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newCi=DataArrayInt::New();
  newCi->alloc(nbOfCells+1,1);
  int *newci=newCi->getPointer();
  const int *ci=_nodal_connec_index->getConstPointer();
  const int *c=_nodal_connec->getConstPointer();
  newci[0]=0;
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)c[ci[i]];
      if(type==INTERP_KERNEL::NORM_POLYHED)
        {
          if(std::count(c+ci[i]+1,c+ci[i+1],-1)!=0)
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::convertExtrudedPolyhedra : cell # " << i << " is a polhedron BUT it has NOT exactly 1 face !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
          std::size_t n2=std::distance(c+ci[i]+1,c+ci[i+1]);
          if(n2%2!=0)
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::convertExtrudedPolyhedra : cell # " << i << " is a polhedron with 1 face but there is a mismatch of number of nodes in face should be even !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
          int n1=(int)(n2/2);
          newci[i+1]=7*n1+2+newci[i];//6*n1 (nodal length) + n1+2 (number of faces) - 1 (number of '-1' separator is equal to number of faces -1) + 1 (for cell type)
        }
      else
        newci[i+1]=(ci[i+1]-ci[i])+newci[i];
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newC=DataArrayInt::New();
  newC->alloc(newci[nbOfCells],1);
  int *newc=newC->getPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)c[ci[i]];
      if(type==INTERP_KERNEL::NORM_POLYHED)
        {
          std::size_t n1=std::distance(c+ci[i]+1,c+ci[i+1])/2;
          newc=std::copy(c+ci[i],c+ci[i]+n1+1,newc);
          *newc++=-1;
          for(std::size_t j=0;j<n1;j++)
            {
              newc[j]=c[ci[i]+1+n1+(n1-j)%n1];
              newc[n1+5*j]=-1;
              newc[n1+5*j+1]=c[ci[i]+1+j];
              newc[n1+5*j+2]=c[ci[i]+1+(j+1)%n1];
              newc[n1+5*j+3]=c[ci[i]+1+(j+1)%n1+n1];
              newc[n1+5*j+4]=c[ci[i]+1+j+n1];
            }
          newc+=n1*6;
        }
      else
        newc=std::copy(c+ci[i],c+ci[i+1],newc);
    }
  _nodal_connec_index->decrRef(); _nodal_connec_index=newCi.retn();
  _nodal_connec->decrRef(); _nodal_connec=newC.retn();
}

/*!
 * This method is the opposite of ParaMEDMEM::MEDCouplingUMesh::convertToPolyTypes method.
 * The aim is to take all polygons or polyhedrons cell and to try to traduce them into classical cells.
 *
 *  \return If true at least one cell has been unpolyzed.
            \n If false has been returned the nodal connectivity of \a this has **not** been altered and \a this has remains unchanged.
 *
 * \warning This method modifies can modify significantly the geometric type order in \a this.
 * In view of the MED file writing, a renumbering of cells in \a this (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
bool MEDCouplingUMesh::unPolyze()
{
  checkFullyDefined();
  int mdim=getMeshDimension();
  if(mdim<0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::unPolyze works on umeshes with meshdim equals to 0, 1 2 or 3 !");
  if(mdim<=1)
    return false;
  int nbOfCells=getNumberOfCells();
  if(nbOfCells<1)
    return false;
  int initMeshLgth=getMeshLength();
  int *conn=_nodal_connec->getPointer();
  int *index=_nodal_connec_index->getPointer();
  int posOfCurCell=0;
  int newPos=0;
  int lgthOfCurCell;
  bool ret=false;
  for(int i=0;i<nbOfCells;i++)
    {
      lgthOfCurCell=index[i+1]-posOfCurCell;
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[posOfCurCell];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
      INTERP_KERNEL::NormalizedCellType newType=INTERP_KERNEL::NORM_ERROR;
      int newLgth;
      if(cm.isDynamic())
        {
          switch(cm.getDimension())
            {
            case 2:
              {
                INTERP_KERNEL::AutoPtr<int> tmp=new int[lgthOfCurCell-1];
                std::copy(conn+posOfCurCell+1,conn+posOfCurCell+lgthOfCurCell,(int *)tmp);
                newType=INTERP_KERNEL::CellSimplify::tryToUnPoly2D(cm.isQuadratic(),tmp,lgthOfCurCell-1,conn+newPos+1,newLgth);
                break;
              }
            case 3:
              {
                int nbOfFaces,lgthOfPolyhConn;
                INTERP_KERNEL::AutoPtr<int> zipFullReprOfPolyh=INTERP_KERNEL::CellSimplify::getFullPolyh3DCell(type,conn+posOfCurCell+1,lgthOfCurCell-1,nbOfFaces,lgthOfPolyhConn);
                newType=INTERP_KERNEL::CellSimplify::tryToUnPoly3D(zipFullReprOfPolyh,nbOfFaces,lgthOfPolyhConn,conn+newPos+1,newLgth);
                break;
              }
            case 1:
              {
                newType=(lgthOfCurCell==3)?INTERP_KERNEL::NORM_SEG2:INTERP_KERNEL::NORM_POLYL;
                break;
              }
            }
          ret=ret || (newType!=type);
          conn[newPos]=newType;
          newPos+=newLgth+1;
          posOfCurCell=index[i+1];
          index[i+1]=newPos;
        }
      else
        {
          std::copy(conn+posOfCurCell,conn+posOfCurCell+lgthOfCurCell,conn+newPos);
          newPos+=lgthOfCurCell;
          posOfCurCell+=lgthOfCurCell;
          index[i+1]=newPos;
        }
    }
  if(newPos!=initMeshLgth)
    _nodal_connec->reAlloc(newPos);
  if(ret)
    computeTypes();
  return ret;
}

/*!
 * This method expects that spaceDimension is equal to 3 and meshDimension equal to 3.
 * This method performs operation only on polyhedrons in \b this. If no polyhedrons exists in \b this, \b this remains unchanged.
 * This method allows to merge if any coplanar 3DSurf cells that may appear in some polyhedrons cells. 
 *
 * \param [in] eps is a relative precision that allows to establish if some 3D plane are coplanar or not. This epsilon is used to recenter around origin to have maximal 
 *             precision.
 */
void MEDCouplingUMesh::simplifyPolyhedra(double eps) throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::simplifyPolyhedra : works on meshdimension 3 and spaceDimension 3 !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coords=getCoords()->deepCpy();
  coords->recenterForMaxPrecision(eps);
  //
  int nbOfCells=getNumberOfCells();
  const int *conn=_nodal_connec->getConstPointer();
  const int *index=_nodal_connec_index->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> connINew=DataArrayInt::New();
  connINew->alloc(nbOfCells+1,1);
  int *connINewPtr=connINew->getPointer(); *connINewPtr++=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> connNew=DataArrayInt::New(); connNew->alloc(0,1);
  bool changed=false;
  for(int i=0;i<nbOfCells;i++,connINewPtr++)
    {
      if(conn[index[i]]==(int)INTERP_KERNEL::NORM_POLYHED)
        {
          SimplifyPolyhedronCell(eps,coords,conn+index[i],conn+index[i+1],connNew);
          changed=true;
        }
      else
        connNew->insertAtTheEnd(conn+index[i],conn+index[i+1]);
      *connINewPtr=connNew->getNumberOfTuples();
    }
  if(changed)
    setConnectivity(connNew,connINew,false);
}

/*!
 * This method returns all node ids used in \b this. The data array returned has to be dealt by the caller.
 * The returned node ids are sortes ascendingly. This method is closed to MEDCouplingUMesh::getNodeIdsInUse except
 * the format of returned DataArrayInt instance.
 * 
 * @return a newly allocated DataArrayInt sorted ascendingly of fetched node ids.
 * \sa MEDCouplingUMesh::getNodeIdsInUse
 */
DataArrayInt *MEDCouplingUMesh::computeFetchedNodeIds() const throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  int nbOfCells=getNumberOfCells();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  const int *maxEltPt=std::max_element(_nodal_connec->begin(),_nodal_connec->end());
  int maxElt=maxEltPt==_nodal_connec->end()?0:std::abs(*maxEltPt)+1;
  std::vector<bool> retS(maxElt,false);
  for(int i=0;i<nbOfCells;i++)
    for(int j=connIndex[i]+1;j<connIndex[i+1];j++)
      if(conn[j]>=0)
        retS[conn[j]]=true;
  int sz=0;
  for(int i=0;i<maxElt;i++)
    if(retS[i])
      sz++;
  DataArrayInt *ret=DataArrayInt::New();
  ret->alloc(sz,1);
  int *retPtr=ret->getPointer();
  for(int i=0;i<maxElt;i++)
    if(retS[i])
      *retPtr++=i;
  return ret;
}

/*!
 * \param [in,out] nodeIdsInUse an array of size typically equal to nbOfNodes.
 * \sa MEDCouplingUMesh::getNodeIdsInUse
 */
void MEDCouplingUMesh::computeNodeIdsAlg(std::vector<bool>& nodeIdsInUse) const throw(INTERP_KERNEL::Exception)
{
  int nbOfNodes=(int)nodeIdsInUse.size();
  int nbOfCells=getNumberOfCells();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    for(int j=connIndex[i]+1;j<connIndex[i+1];j++)
      if(conn[j]>=0)
        {
          if(conn[j]<nbOfNodes)
            nodeIdsInUse[conn[j]]=true;
          else
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::getNodeIdsInUse : In cell #" << i  << " presence of node id " <<  conn[j] << " not in [0," << nbOfNodes << ") !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
}

/*!
 * Array returned is the correspondance in \b old \b to \b new format (that's why 'nbrOfNodesInUse' is returned too).
 * The returned array is newly created and should be dealt by the caller.
 * To retrieve the new to old format the user can use DataArrayInt::invertArrayO2N2N2O method.
 * The size of returned array is the number of nodes of 'this'.
 * -1 values in returned array means that the corresponding node never appear in any nodal connectivity of cells constituting 'this'.
 * @param [out] nbrOfNodesInUse out parameter that specifies how many of nodes in 'this' is really used in nodal connectivity.
 * @return a newly allocated DataArrayInt that tells for each nodeid in \b this if it is unused (-1) or used (the corresponding new id)
 * \throw if a cell contains in its nodal connectivity a node id >= nb of nodes an exception will be thrown.
 * \sa MEDCouplingUMesh::computeNodeIdsAlg
 */
DataArrayInt *MEDCouplingUMesh::getNodeIdsInUse(int& nbrOfNodesInUse) const throw(INTERP_KERNEL::Exception)
{
  nbrOfNodesInUse=-1;
  int nbOfNodes=getNumberOfNodes();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  ret->alloc(nbOfNodes,1);
  int *traducer=ret->getPointer();
  std::fill(traducer,traducer+nbOfNodes,-1);
  int nbOfCells=getNumberOfCells();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    for(int j=connIndex[i]+1;j<connIndex[i+1];j++)
      if(conn[j]>=0)
        {
          if(conn[j]<nbOfNodes)
            traducer[conn[j]]=1;
          else
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::getNodeIdsInUse : In cell #" << i  << " presence of node id " <<  conn[j] << " not in [0," << nbOfNodes << ") !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
  nbrOfNodesInUse=(int)std::count(traducer,traducer+nbOfNodes,1);
  std::transform(traducer,traducer+nbOfNodes,traducer,MEDCouplingAccVisit());
  return ret.retn();
}

/*!
 * This method returns a newly allocated array containing this->getNumberOfCells() tuples and 1 component.
 * For each cell in \b this the number of nodes constituting cell is computed.
 * Excepted for poyhedrons, the result can be deduced by performing a deltaShiftIndex on the nodal connectivity index in \b this minus 1.
 * For polyhedrons, the face separation (-1) are excluded from the couting.
 * 
 * \return a newly allocated array
 */
DataArrayInt *MEDCouplingUMesh::computeNbOfNodesPerCell() const throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  ret->alloc(nbOfCells,1);
  int *retPtr=ret->getPointer();
  const int *conn=getNodalConnectivity()->getConstPointer();
  const int *connI=getNodalConnectivityIndex()->getConstPointer();
  for(int i=0;i<nbOfCells;i++,retPtr++)
    {
      if(conn[connI[i]]!=(int)INTERP_KERNEL::NORM_POLYHED)
        *retPtr=connI[i+1]-connI[i]-1;
      else
        *retPtr=connI[i+1]-connI[i]-1-std::count(conn+connI[i]+1,conn+connI[i+1],-1);
    }
  return ret.retn();
}

/*!
 * Array returned is the correspondance in \b old \b to \b new format. The returned array is newly created and should be dealt by the caller.
 * The maximum value stored in returned array is the number of nodes of 'this' minus 1 after call of this method.
 * The size of returned array is the number of nodes of the old (previous to the call of this method) number of nodes.
 * -1 values in returned array means that the corresponding old node is no more used.
 */
DataArrayInt *MEDCouplingUMesh::zipCoordsTraducer() throw(INTERP_KERNEL::Exception)
{
  int newNbOfNodes=-1;
  DataArrayInt *traducer=getNodeIdsInUse(newNbOfNodes);
  renumberNodes(traducer->getConstPointer(),newNbOfNodes);
  return traducer;
}

/*!
 * This method stands if 'cell1' and 'cell2' are equals regarding 'compType' policy.
 * The semantic of 'compType' is specified in MEDCouplingUMesh::zipConnectivityTraducer method.
 */
int MEDCouplingUMesh::AreCellsEqual(const int *conn, const int *connI, int cell1, int cell2, int compType)
{
  switch(compType)
    {
    case 0:
      return AreCellsEqual0(conn,connI,cell1,cell2);
    case 1:
      return AreCellsEqual1(conn,connI,cell1,cell2);
    case 2:
      return AreCellsEqual2(conn,connI,cell1,cell2);
    case 3:
      return AreCellsEqual3(conn,connI,cell1,cell2);
    case 7:
      return AreCellsEqual7(conn,connI,cell1,cell2);
    }
  throw INTERP_KERNEL::Exception("Unknown comparison asked ! Must be in 0,1,2 or 3.");
}

/*!
 * This method is the last step of the MEDCouplingUMesh::zipConnectivityTraducer with policy 0.
 */
int MEDCouplingUMesh::AreCellsEqual0(const int *conn, const int *connI, int cell1, int cell2)
{
  if(connI[cell1+1]-connI[cell1]==connI[cell2+1]-connI[cell2])
    return std::equal(conn+connI[cell1]+1,conn+connI[cell1+1],conn+connI[cell2]+1)?1:0;
  return 0;
}

/*!
 * This method is the last step of the MEDCouplingUMesh::zipConnectivityTraducer with policy 1.
 */
int MEDCouplingUMesh::AreCellsEqual1(const int *conn, const int *connI, int cell1, int cell2)
{
  int sz=connI[cell1+1]-connI[cell1];
  if(sz==connI[cell2+1]-connI[cell2])
    {
      if(conn[connI[cell1]]==conn[connI[cell2]])
        {
          const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[connI[cell1]]);
          unsigned dim=cm.getDimension();
          if(dim!=3)
            {
              if(dim!=1)
                {
                  int sz1=2*(sz-1);
                  INTERP_KERNEL::AutoPtr<int> tmp=new int[sz1];
                  int *work=std::copy(conn+connI[cell1]+1,conn+connI[cell1+1],(int *)tmp);
                  std::copy(conn+connI[cell1]+1,conn+connI[cell1+1],work);
                  work=std::search((int *)tmp,(int *)tmp+sz1,conn+connI[cell2]+1,conn+connI[cell2+1]);
                  return work!=tmp+sz1?1:0;
                }
              else
                return std::equal(conn+connI[cell1]+1,conn+connI[cell1+1],conn+connI[cell2]+1)?1:0;//case of SEG2 and SEG3
            }
          else
            throw INTERP_KERNEL::Exception("MEDCouplingUMesh::AreCellsEqual1 : not implemented yet for meshdim == 3 !");
        }
    }
  return 0;
}

/*!
 * This method is the last step of the MEDCouplingUMesh::zipConnectivityTraducer with policy 2.
 */
int MEDCouplingUMesh::AreCellsEqual2(const int *conn, const int *connI, int cell1, int cell2)
{
  if(connI[cell1+1]-connI[cell1]==connI[cell2+1]-connI[cell2])
    {
      if(conn[connI[cell1]]==conn[connI[cell2]])
        {
          std::set<int> s1(conn+connI[cell1]+1,conn+connI[cell1+1]);
          std::set<int> s2(conn+connI[cell2]+1,conn+connI[cell2+1]);
          return s1==s2?1:0;
        }
    }
  return 0;
}

/*!
 * This method is less restrictive than AreCellsEqual2. Here the geometric type is absolutely not taken into account !
 */
int MEDCouplingUMesh::AreCellsEqual3(const int *conn, const int *connI, int cell1, int cell2)
{
  if(connI[cell1+1]-connI[cell1]==connI[cell2+1]-connI[cell2])
    {
      std::set<int> s1(conn+connI[cell1]+1,conn+connI[cell1+1]);
      std::set<int> s2(conn+connI[cell2]+1,conn+connI[cell2+1]);
      return s1==s2?1:0;
    }
  return 0;
}

/*!
 * This method is the last step of the MEDCouplingUMesh::zipConnectivityTraducer with policy 7.
 */
int MEDCouplingUMesh::AreCellsEqual7(const int *conn, const int *connI, int cell1, int cell2)
{
  int sz=connI[cell1+1]-connI[cell1];
  if(sz==connI[cell2+1]-connI[cell2])
    {
      if(conn[connI[cell1]]==conn[connI[cell2]])
        {
          const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[connI[cell1]]);
          unsigned dim=cm.getDimension();
          if(dim!=3)
            {
              if(dim!=1)
                {
                  int sz1=2*(sz-1);
                  INTERP_KERNEL::AutoPtr<int> tmp=new int[sz1];
                  int *work=std::copy(conn+connI[cell1]+1,conn+connI[cell1+1],(int *)tmp);
                  std::copy(conn+connI[cell1]+1,conn+connI[cell1+1],work);
                  work=std::search((int *)tmp,(int *)tmp+sz1,conn+connI[cell2]+1,conn+connI[cell2+1]);
                  if(work!=tmp+sz1)
                    return 1;
                  else
                    {
                      std::reverse_iterator<int *> it1((int *)tmp+sz1);
                      std::reverse_iterator<int *> it2((int *)tmp);
                      if(std::search(it1,it2,conn+connI[cell2]+1,conn+connI[cell2+1])!=it2)
                        return 2;
                      else
                        return 0;
                    }
                  
                  return work!=tmp+sz1?1:0;
                }
              else
                {//case of SEG2 and SEG3
                  if(std::equal(conn+connI[cell1]+1,conn+connI[cell1+1],conn+connI[cell2]+1))
                    return 1;
                  if(!cm.isQuadratic())
                    {
                      std::reverse_iterator<const int *> it1(conn+connI[cell1+1]);
                      std::reverse_iterator<const int *> it2(conn+connI[cell1]+1);
                      if(std::equal(it1,it2,conn+connI[cell2]+1))
                        return 2;
                      return 0;
                    }
                  else
                    {
                      if(conn[connI[cell1]+1]==conn[connI[cell2]+2] && conn[connI[cell1]+2]==conn[connI[cell2]+1] && conn[connI[cell1]+3]==conn[connI[cell2]+3])
                        return 2;
                      return 0;
                    }
                }
            }
          else
            throw INTERP_KERNEL::Exception("MEDCouplingUMesh::AreCellsEqual7 : not implemented yet for meshdim == 3 !");
        }
    }
  return 0;
}


/*!
 * This method compares 2 cells coming from two unstructured meshes : 'this' and 'other'.
 * This method compares 2 cells having the same id 'cellId' in 'this' and 'other'.
 */
bool MEDCouplingUMesh::areCellsFrom2MeshEqual(const MEDCouplingUMesh *other, int cellId, double prec) const
{
  if(getTypeOfCell(cellId)!=other->getTypeOfCell(cellId))
    return false;
  std::vector<int> c1,c2;
  getNodeIdsOfCell(cellId,c1);
  other->getNodeIdsOfCell(cellId,c2);
  std::size_t sz=c1.size();
  if(sz!=c2.size())
    return false;
  for(std::size_t i=0;i<sz;i++)
    {
      std::vector<double> n1,n2;
      getCoordinatesOfNode(c1[0],n1);
      other->getCoordinatesOfNode(c2[0],n2);
      std::transform(n1.begin(),n1.end(),n2.begin(),n1.begin(),std::minus<double>());
      std::transform(n1.begin(),n1.end(),n1.begin(),std::ptr_fun<double,double>(fabs));
      if(*std::max_element(n1.begin(),n1.end())>prec)
        return false;
    }
  return true;
}

/*!
 * This method find in candidate pool defined by 'candidates' the cells equal following the polycy 'compType'.
 * If any true is returned and the results will be put at the end of 'result' output parameter. If not false is returned
 * and result remains unchanged.
 * The semantic of 'compType' is specified in MEDCouplingUMesh::zipConnectivityTraducer method.
 * If in 'candidates' pool -1 value is considered as an empty value.
 * WARNING this method returns only ONE set of result !
 */
bool MEDCouplingUMesh::AreCellsEqualInPool(const std::vector<int>& candidates, int compType, const int *conn, const int *connI, DataArrayInt *result)
{
  if(candidates.size()<1)
    return false;
  bool ret=false;
  std::vector<int>::const_iterator iter=candidates.begin();
  int start=(*iter++);
  for(;iter!=candidates.end();iter++)
    {
      int status=AreCellsEqual(conn,connI,start,*iter,compType);
      if(status!=0)
        {
          if(!ret)
            {
              result->pushBackSilent(start);
              ret=true;
            }
          if(status==1)
            result->pushBackSilent(*iter);
          else
            result->pushBackSilent(status==2?(*iter+1):-(*iter+1));
        }
    }
  return ret;
}

/*!
 * This method find cells that are cells equal (regarding \a compType) in \a this. The comparison is specified by \a compType.
 * This method keeps the coordiantes of \a this. This method is time consuming and is called 
 *
 * \param [in] compType input specifying the technique used to compare cells each other.
 *   - 0 : exactly. A cell is detected to be the same if and only if the connectivity is exactly the same without permutation and types same too. This is the strongest policy.
 *   - 1 : permutation same orientation. cell1 and cell2 are considered equal if the connectivity of cell2 can be deduced by those of cell1 by direct permutation (with exactly the same orientation)
 * and their type equal. For 1D mesh the policy 1 is equivalent to 0.
 *   - 2 : nodal. cell1 and cell2 are equal if and only if cell1 and cell2 have same type and have the same nodes constituting connectivity. This is the laziest policy. This policy
 * can be used for users not sensitive to orientation of cell
 * \param [in] startCellId specifies the cellId starting from which the equality computation will be carried out. By default it is 0, which it means that all cells in \a this will be scanned.
 * \param [out] commonCells
 * \param [out] commonCellsI
 * \return the correspondance array old to new in a newly allocated array.
 * 
 */
void MEDCouplingUMesh::findCommonCells(int compType, int startCellId, DataArrayInt *& commonCellsArr, DataArrayInt *& commonCellsIArr) const throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revNodal=DataArrayInt::New(),revNodalI=DataArrayInt::New();
  getReverseNodalConnectivity(revNodal,revNodalI);
  FindCommonCellsAlg(compType,startCellId,_nodal_connec,_nodal_connec_index,revNodal,revNodalI,commonCellsArr,commonCellsIArr);
}

void MEDCouplingUMesh::FindCommonCellsAlg(int compType, int startCellId, const DataArrayInt *nodal, const DataArrayInt *nodalI, const DataArrayInt *revNodal, const DataArrayInt *revNodalI,
                                          DataArrayInt *& commonCellsArr, DataArrayInt *& commonCellsIArr) throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> commonCells=DataArrayInt::New(),commonCellsI=DataArrayInt::New(); commonCells->alloc(0,1);
  int nbOfCells=nodalI->getNumberOfTuples()-1;
  commonCellsI->reserve(1); commonCellsI->pushBackSilent(0);
  const int *revNodalPtr=revNodal->getConstPointer(),*revNodalIPtr=revNodalI->getConstPointer();
  const int *connPtr=nodal->getConstPointer(),*connIPtr=nodalI->getConstPointer();
  std::vector<bool> isFetched(nbOfCells,false);
  if(startCellId==0)
    {
      for(int i=0;i<nbOfCells;i++)
        {
          if(!isFetched[i])
            {
              const int *connOfNode=std::find_if(connPtr+connIPtr[i]+1,connPtr+connIPtr[i+1],std::bind2nd(std::not_equal_to<int>(),-1));
              std::vector<int> v,v2;
              if(connOfNode!=connPtr+connIPtr[i+1])
                {
                  const int *locRevNodal=std::find(revNodalPtr+revNodalIPtr[*connOfNode],revNodalPtr+revNodalIPtr[*connOfNode+1],i);
                  v2.insert(v2.end(),locRevNodal,revNodalPtr+revNodalIPtr[*connOfNode+1]);
                  connOfNode++;
                }
              for(;connOfNode!=connPtr+connIPtr[i+1] && v2.size()>1;connOfNode++)
                if(*connOfNode>=0)
                  {
                    v=v2;
                    const int *locRevNodal=std::find(revNodalPtr+revNodalIPtr[*connOfNode],revNodalPtr+revNodalIPtr[*connOfNode+1],i);
                    std::vector<int>::iterator it=std::set_intersection(v.begin(),v.end(),locRevNodal,revNodalPtr+revNodalIPtr[*connOfNode+1],v2.begin());
                    v2.resize(std::distance(v2.begin(),it));
                  }
              if(v2.size()>1)
                {
                  if(AreCellsEqualInPool(v2,compType,connPtr,connIPtr,commonCells))
                    {
                      int pos=commonCellsI->back();
                      commonCellsI->pushBackSilent(commonCells->getNumberOfTuples());
                      for(const int *it=commonCells->begin()+pos;it!=commonCells->end();it++)
                        isFetched[*it]=true;
                    }
                }
            }
        }
    }
  else
    {
      for(int i=startCellId;i<nbOfCells;i++)
        {
          if(!isFetched[i])
            {
              const int *connOfNode=std::find_if(connPtr+connIPtr[i]+1,connPtr+connIPtr[i+1],std::bind2nd(std::not_equal_to<int>(),-1));
              std::vector<int> v,v2;
              if(connOfNode!=connPtr+connIPtr[i+1])
                {
                  v2.insert(v2.end(),revNodalPtr+revNodalIPtr[*connOfNode],revNodalPtr+revNodalIPtr[*connOfNode+1]);
                  connOfNode++;
                }
              for(;connOfNode!=connPtr+connIPtr[i+1] && v2.size()>1;connOfNode++)
                if(*connOfNode>=0)
                  {
                    v=v2;
                    std::vector<int>::iterator it=std::set_intersection(v.begin(),v.end(),revNodalPtr+revNodalIPtr[*connOfNode],revNodalPtr+revNodalIPtr[*connOfNode+1],v2.begin());
                    v2.resize(std::distance(v2.begin(),it));
                  }
              if(v2.size()>1)
                {
                  if(AreCellsEqualInPool(v2,compType,connPtr,connIPtr,commonCells))
                    {
                      int pos=commonCellsI->back();
                      commonCellsI->pushBackSilent(commonCells->getNumberOfTuples());
                      for(const int *it=commonCells->begin()+pos;it!=commonCells->end();it++)
                        isFetched[*it]=true;
                    }
                }
            }
        }
    }
  commonCellsArr=commonCells.retn();
  commonCellsIArr=commonCellsI.retn();
}

/*!
 * This method could potentially modify \a this. This method merges cells if there are cells equal in \a this. The comparison is specified by \a compType.
 * This method keeps the coordiantes of \a this.
 *
 * \param [in] compType input specifying the technique used to compare cells each other.
 *   - 0 : exactly. A cell is detected to be the same if and only if the connectivity is exactly the same without permutation and types same too. This is the strongest policy.
 *   - 1 : permutation same orientation. cell1 and cell2 are considered equal if the connectivity of cell2 can be deduced by those of cell1 by direct permutation (with exactly the same orientation)
 * and their type equal. For 1D mesh the policy 1 is equivalent to 0.
 *   - 2 : nodal. cell1 and cell2 are equal if and only if cell1 and cell2 have same type and have the same nodes constituting connectivity. This is the laziest policy. This policy
 * can be used for users not sensitive to orientation of cell
 * \param [in] startCellId specifies the cellId starting from which the equality computation will be carried out. By default it is 0, which it means that all cells in \a this will be scanned
 * \return the correspondance array old to new in a newly allocated array.
 * 
 * \warning This method modifies can modify significantly the geometric type order in \a this.
 * In view of the MED file writing, a renumbering of cells in \a this (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
DataArrayInt *MEDCouplingUMesh::zipConnectivityTraducer(int compType, int startCellId) throw(INTERP_KERNEL::Exception)
{
  DataArrayInt *commonCells=0,*commonCellsI=0;
  findCommonCells(compType,startCellId,commonCells,commonCellsI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> commonCellsTmp(commonCells),commonCellsITmp(commonCellsI);
  int newNbOfCells=-1;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::BuildOld2NewArrayFromSurjectiveFormat2(getNumberOfCells(),commonCells->begin(),commonCellsI->begin(),
                                                                                                          commonCellsI->end(),newNbOfCells);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret2=ret->invertArrayO2N2N2O(newNbOfCells);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> self=static_cast<MEDCouplingUMesh *>(buildPartOfMySelf(ret2->begin(),ret2->end(),true));
  setConnectivity(self->getNodalConnectivity(),self->getNodalConnectivityIndex(),true);
  return ret.retn();
}

/*!
 * This method makes the assumption that 'this' and 'other' share the same coords. If not an exception will be thrown !
 * This method tries to determine if 'other' is fully included in 'this'. To compute that, this method works with connectivity as MEDCouplingUMesh::zipConnectivityTraducer method does. 
 * This method is close to MEDCouplingUMesh::checkDeepEquivalOnSameNodesWith or MEDCouplingMesh::checkGeoEquivalWith with policy 20,21,or 22.
 * The main difference is that this method is not expected to throw exception.
 * This method has two outputs :
 *
 * @param compType is the comparison type. The possible values of this parameter are described in ParaMEDMEM::MEDCouplingUMesh::zipConnectivityTraducer method
 * @param arr is an output parameter that returns a \b newly created instance. This array is of size 'other->getNumberOfCells()'.
 * @return If 'other' is fully included in 'this 'true is returned. If not false is returned.
 */
bool MEDCouplingUMesh::areCellsIncludedIn(const MEDCouplingUMesh *other, int compType, DataArrayInt *& arr) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mesh=MergeUMeshesOnSameCoords(this,other);
  int nbOfCells=getNumberOfCells();
  static const int possibleCompType[]={0,1,2};
  if(std::find(possibleCompType,possibleCompType+sizeof(possibleCompType)/sizeof(int),compType)==possibleCompType+sizeof(possibleCompType)/sizeof(int))
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::areCellsIncludedIn : only following policies are possible : ";
      std::copy(possibleCompType,possibleCompType+sizeof(possibleCompType)/sizeof(int),std::ostream_iterator<int>(oss," "));
      oss << " !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> o2n=mesh->zipConnectivityTraducer(compType,nbOfCells);
  arr=o2n->substr(nbOfCells);
  arr->setName(other->getName());
  int tmp;
  if(other->getNumberOfCells()==0)
    return true;
  return arr->getMaxValue(tmp)<nbOfCells;
}

/*!
 * This method makes the assumption that 'this' and 'other' share the same coords. If not an exception will be thrown !
 * This method tries to determine if \b other is fully included in \b this.
 * The main difference is that this method is not expected to throw exception.
 * This method has two outputs :
 *
 * @param arr is an output parameter that returns a \b newly created instance. This array is of size 'other->getNumberOfCells()'.
 * @return If 'other' is fully included in 'this 'true is returned. If not false is returned.
 */
bool MEDCouplingUMesh::areCellsIncludedIn2(const MEDCouplingUMesh *other, DataArrayInt *& arr) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mesh=MergeUMeshesOnSameCoords(this,other);
  DataArrayInt *commonCells=0,*commonCellsI=0;
  int thisNbCells=getNumberOfCells();
  mesh->findCommonCells(7,thisNbCells,commonCells,commonCellsI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> commonCellsTmp(commonCells),commonCellsITmp(commonCellsI);
  const int *commonCellsPtr=commonCells->getConstPointer(),*commonCellsIPtr=commonCellsI->getConstPointer();
  int otherNbCells=other->getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arr2=DataArrayInt::New();
  arr2->alloc(otherNbCells,1);
  arr2->fillWithZero();
  int *arr2Ptr=arr2->getPointer();
  int nbOfCommon=commonCellsI->getNumberOfTuples()-1;
  for(int i=0;i<nbOfCommon;i++)
    {
      int start=commonCellsPtr[commonCellsIPtr[i]];
      if(start<thisNbCells)
        {
          for(int j=commonCellsIPtr[i]+1;j!=commonCellsIPtr[i+1];j++)
            {
              int sig=commonCellsPtr[j]>0?1:-1;
              int val=std::abs(commonCellsPtr[j])-1;
              if(val>=thisNbCells)
                arr2Ptr[val-thisNbCells]=sig*(start+1);
            }
        }
    }
  arr2->setName(other->getName());
  if(arr2->presenceOfValue(0))
    return false;
  arr=arr2.retn();
  return true;
}

/*!
 * @param areNodesMerged if at least two nodes have been merged.
 * @return old to new node correspondance.
 */
DataArrayInt *MEDCouplingUMesh::mergeNodes(double precision, bool& areNodesMerged, int& newNbOfNodes)
{
  DataArrayInt *ret=buildPermArrayForMergeNode(precision,-1,areNodesMerged,newNbOfNodes);
  if(areNodesMerged)
    renumberNodes(ret->getConstPointer(),newNbOfNodes);
  return ret;
}

/*!
 * Idem ParaMEDMEM::MEDCouplingUMesh::mergeNodes method except that the merged nodes are meld into the barycenter of them.
 */
DataArrayInt *MEDCouplingUMesh::mergeNodes2(double precision, bool& areNodesMerged, int& newNbOfNodes)
{
  DataArrayInt *ret=buildPermArrayForMergeNode(precision,-1,areNodesMerged,newNbOfNodes);
  if(areNodesMerged)
    renumberNodes2(ret->getConstPointer(),newNbOfNodes);
  return ret;
}

/*!
 * This method tries to use 'other' coords and use it for 'this'. If no exception was thrown after the call of this method :
 * this->_coords==other->_coords. If an exception is thrown 'this' remains unchanged.
 * Contrary to MEDCouplingUMesh::tryToShareSameCoords method this method makes a deeper analyze of coordinates (and so more expensive) than simple equality.
 * Two nodes one in 'this' and other in 'other' are considered equal if the distance between the two is lower than epsilon.
 */
void MEDCouplingUMesh::tryToShareSameCoordsPermute(const MEDCouplingPointSet& other, double epsilon) throw(INTERP_KERNEL::Exception)
{
  const DataArrayDouble *coords=other.getCoords();
  if(!coords)
    throw INTERP_KERNEL::Exception("tryToShareSameCoordsPermute : No coords specified in other !");
  if(!_coords)
    throw INTERP_KERNEL::Exception("tryToShareSameCoordsPermute : No coords specified in this whereas there is any in other !");
  int otherNbOfNodes=other.getNumberOfNodes();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> newCoords=MergeNodesArray(&other,this);
  _coords->incrRef();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> oldCoords=_coords;
  setCoords(newCoords);
  bool areNodesMerged;
  int newNbOfNodes;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> da=buildPermArrayForMergeNode(epsilon,otherNbOfNodes,areNodesMerged,newNbOfNodes);
  if(!areNodesMerged)
    {
      setCoords(oldCoords);
      throw INTERP_KERNEL::Exception("tryToShareSameCoordsPermute fails : no nodes are mergeable with specified given epsilon !");
    }
  int maxId=*std::max_element(da->getConstPointer(),da->getConstPointer()+otherNbOfNodes);
  const int *pt=std::find_if(da->getConstPointer()+otherNbOfNodes,da->getConstPointer()+da->getNbOfElems(),std::bind2nd(std::greater<int>(),maxId));
  if(pt!=da->getConstPointer()+da->getNbOfElems())
    {
      setCoords(oldCoords);
      throw INTERP_KERNEL::Exception("tryToShareSameCoordsPermute fails : some nodes in this are not in other !");
    }
  setCoords(oldCoords);
  renumberNodesInConn(da->getConstPointer()+otherNbOfNodes);
  setCoords(coords);
}

/*!
 * Build a sub part of \b this lying or not on the same coordinates than \b this (regarding value of \b keepCoords).
 * By default coordinates are kept. This method is close to MEDCouplingUMesh::buildPartOfMySelf except that here input
 * cellIds is not given explicitely but by a range python like.
 * 
 * \param keepCoords that specifies if you want or not to keep coords as this or zip it (see ParaMEDMEM::MEDCouplingUMesh::zipCoords). If true zipCoords is \b NOT called, if false, zipCoords is called.
 * \return a newly allocated
 * 
 * \warning This method modifies can generate an unstructured mesh whose cells are not sorted by geometric type order.
 * In view of the MED file writing, a renumbering of cells of returned unstructured mesh (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
MEDCouplingPointSet *MEDCouplingUMesh::buildPartOfMySelf2(int start, int end, int step, bool keepCoords) const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=-1)
    {
      MEDCouplingUMesh *ret=buildPartOfMySelfKeepCoords2(start,end,step);
      if(!keepCoords)
        ret->zipCoords();
      return ret;
    }
  else
    {
      int newNbOfCells=DataArray::GetNumberOfItemGivenBESRelative(start,end,step,"MEDCouplingUMesh::buildPartOfMySelf2 for -1 dimension mesh ");
      if(newNbOfCells!=1)
        throw INTERP_KERNEL::Exception("-1D mesh has only one cell !");
      if(start!=0)
        throw INTERP_KERNEL::Exception("-1D mesh has only one cell : 0 !");
      incrRef();
      return const_cast<MEDCouplingUMesh *>(this);
    }
}

/*!
 * build a sub part of \b this. This sub part is defined by the cell ids contained in the array in [begin,end).
 * @param begin begin of array containing the cell ids to keep.
 * @param end end of array of cell ids to keep. \b WARNING end param is \b not included ! Idem STL standard definitions.
 * @param keepCoords that specifies if you want or not to keep coords as this or zip it (see ParaMEDMEM::MEDCouplingUMesh::zipCoords). If true zipCoords is \b NOT called, if false, zipCoords is called.
 * 
 * \warning This method modifies can generate an unstructured mesh whose cells are not sorted by geometric type order.
 * In view of the MED file writing, a renumbering of cells of returned unstructured mesh (using MEDCouplingUMesh::sortCellsInMEDFileFrmt) should be necessary.
 */
MEDCouplingPointSet *MEDCouplingUMesh::buildPartOfMySelf(const int *begin, const int *end, bool keepCoords) const
{
  if(getMeshDimension()!=-1)
    {
      MEDCouplingUMesh *ret=buildPartOfMySelfKeepCoords(begin,end);
      if(!keepCoords)
        ret->zipCoords();
      return ret;
    }
  else
    {
      if(end-begin!=1)
        throw INTERP_KERNEL::Exception("-1D mesh has only one cell !");
      if(begin[0]!=0)
        throw INTERP_KERNEL::Exception("-1D mesh has only one cell : 0 !");
      incrRef();
      return const_cast<MEDCouplingUMesh *>(this);
    }
}

/*!
 * This method operates only on nodal connectivity on \b this. Coordinates of \b this is completely ignored here.
 *
 * This method allows to partially modify some cells in \b this (whose list is specified by [\b cellIdsBg, \b cellIdsEnd) ) with cells coming in \b otherOnSameCoordsThanThis.
 * Size of [\b cellIdsBg, \b cellIdsEnd) ) must be equal to the number of cells of otherOnSameCoordsThanThis.
 * The number of cells of \b this will remain the same with this method.
 *
 * \param [in] begin begin of cell ids (included) of cells in this to assign
 * \param [in] end end of cell ids (excluded) of cells in this to assign
 * \param [in] otherOnSameCoordsThanThis an another mesh with same meshdimension than \b this with exactly the same number of cells than cell ids list in [\b cellIdsBg, \b cellIdsEnd).
 *             Coordinate pointer of \b this and those of \b otherOnSameCoordsThanThis must be the same
 */
void MEDCouplingUMesh::setPartOfMySelf(const int *cellIdsBg, const int *cellIdsEnd, const MEDCouplingUMesh& otherOnSameCoordsThanThis) throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  otherOnSameCoordsThanThis.checkConnectivityFullyDefined();
  if(getCoords()!=otherOnSameCoordsThanThis.getCoords())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::setPartOfMySelf : coordinates pointer are not the same ! Invoke setCoords or call tryToShareSameCoords method !");
  if(getMeshDimension()!=otherOnSameCoordsThanThis.getMeshDimension())
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::setPartOfMySelf : Mismatch of meshdimensions ! this is equal to " << getMeshDimension();
      oss << ", whereas other mesh dimension is set equal to " << otherOnSameCoordsThanThis.getMeshDimension() << " !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  int nbOfCellsToModify=(int)std::distance(cellIdsBg,cellIdsEnd);
  if(nbOfCellsToModify!=otherOnSameCoordsThanThis.getNumberOfCells())
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::setPartOfMySelf : cells ids length (" <<  nbOfCellsToModify << ") do not match the number of cells of other mesh (" << otherOnSameCoordsThanThis.getNumberOfCells() << ") !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  int nbOfCells=getNumberOfCells();
  bool easyAssign=true;
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *connIOther=otherOnSameCoordsThanThis._nodal_connec_index->getConstPointer();
  for(const int *it=cellIdsBg;it!=cellIdsEnd && easyAssign;it++,connIOther++)
    {
      if(*it>=0 && *it<nbOfCells)
        {
          easyAssign=(connIOther[1]-connIOther[0])==(connI[*it+1]-connI[*it]);
        }
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::setPartOfMySelf : On pos #" << std::distance(cellIdsBg,it) << " id is equal to " << *it << " which is not in [0," << nbOfCells << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  if(easyAssign)
    {
      MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx(cellIdsBg,cellIdsEnd,_nodal_connec,_nodal_connec_index,otherOnSameCoordsThanThis._nodal_connec,otherOnSameCoordsThanThis._nodal_connec_index);
      computeTypes();
    }
  else
    {
      DataArrayInt *arrOut=0,*arrIOut=0;
      MEDCouplingUMesh::SetPartOfIndexedArrays(cellIdsBg,cellIdsEnd,_nodal_connec,_nodal_connec_index,otherOnSameCoordsThanThis._nodal_connec,otherOnSameCoordsThanThis._nodal_connec_index,
                                               arrOut,arrIOut);
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arrOutAuto(arrOut),arrIOutAuto(arrIOut);
      setConnectivity(arrOut,arrIOut,true);
    }
}

void MEDCouplingUMesh::setPartOfMySelf2(int start, int end, int step, const MEDCouplingUMesh& otherOnSameCoordsThanThis) throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  otherOnSameCoordsThanThis.checkConnectivityFullyDefined();
  if(getCoords()!=otherOnSameCoordsThanThis.getCoords())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::setPartOfMySelf2 : coordinates pointer are not the same ! Invoke setCoords or call tryToShareSameCoords method !");
  if(getMeshDimension()!=otherOnSameCoordsThanThis.getMeshDimension())
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::setPartOfMySelf2 : Mismatch of meshdimensions ! this is equal to " << getMeshDimension();
      oss << ", whereas other mesh dimension is set equal to " << otherOnSameCoordsThanThis.getMeshDimension() << " !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  int nbOfCellsToModify=DataArray::GetNumberOfItemGivenBESRelative(start,end,step,"MEDCouplingUMesh::setPartOfMySelf2 : ");
  if(nbOfCellsToModify!=otherOnSameCoordsThanThis.getNumberOfCells())
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::setPartOfMySelf2 : cells ids length (" <<  nbOfCellsToModify << ") do not match the number of cells of other mesh (" << otherOnSameCoordsThanThis.getNumberOfCells() << ") !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  int nbOfCells=getNumberOfCells();
  bool easyAssign=true;
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *connIOther=otherOnSameCoordsThanThis._nodal_connec_index->getConstPointer();
  int it=start;
  for(int i=0;i<nbOfCellsToModify && easyAssign;i++,it+=step,connIOther++)
    {
      if(it>=0 && it<nbOfCells)
        {
          easyAssign=(connIOther[1]-connIOther[0])==(connI[it+1]-connI[it]);
        }
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::setPartOfMySelf2 : On pos #" << i << " id is equal to " << it << " which is not in [0," << nbOfCells << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  if(easyAssign)
    {
      MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx2(start,end,step,_nodal_connec,_nodal_connec_index,otherOnSameCoordsThanThis._nodal_connec,otherOnSameCoordsThanThis._nodal_connec_index);
      computeTypes();
    }
  else
    {
      DataArrayInt *arrOut=0,*arrIOut=0;
      MEDCouplingUMesh::SetPartOfIndexedArrays2(start,end,step,_nodal_connec,_nodal_connec_index,otherOnSameCoordsThanThis._nodal_connec,otherOnSameCoordsThanThis._nodal_connec_index,
                                                arrOut,arrIOut);
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arrOutAuto(arrOut),arrIOutAuto(arrIOut);
      setConnectivity(arrOut,arrIOut,true);
    }
}                      

DataArrayInt *MEDCouplingUMesh::getCellIdsFullyIncludedInNodeIds(const int *partBg, const int *partEnd) const
{
  DataArrayInt *cellIdsKept=0;
  fillCellIdsToKeepFromNodeIds(partBg,partEnd,true,cellIdsKept);
  cellIdsKept->setName(getName());
  return cellIdsKept;
}

/*!
 * Keeps from 'this' only cells which constituing point id are in the ids specified by ['begin','end').
 * The resulting cell ids are stored at the end of the 'cellIdsKept' parameter.
 * Parameter 'fullyIn' specifies if a cell that has part of its nodes in ids array is kept or not.
 * If 'fullyIn' is true only cells whose ids are \b fully contained in ['begin','end') tab will be kept.
 *
 * \param [in] begin input start of array of node ids.
 * \param [in] end input end of array of node ids.
 * \param [in] fullyIn input that specifies if all node ids must be in ['begin','end') array to consider cell to be in.
 * \param [in,out] cellIdsKeptArr array where all candidate cell ids are put at the end.
 */
void MEDCouplingUMesh::fillCellIdsToKeepFromNodeIds(const int *begin, const int *end, bool fullyIn, DataArrayInt *&cellIdsKeptArr) const
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIdsKept=DataArrayInt::New(); cellIdsKept->alloc(0,1);
  checkConnectivityFullyDefined();
  int tmp=-1;
  int sz=getNodalConnectivity()->getMaxValue(tmp); sz=std::max(sz,0)+1;
  std::vector<bool> fastFinder(sz,false);
  for(const int *work=begin;work!=end;work++)
    if(*work>=0 && *work<sz)
      fastFinder[*work]=true;
  int nbOfCells=getNumberOfCells();
  const int *conn=getNodalConnectivity()->getConstPointer();
  const int *connIndex=getNodalConnectivityIndex()->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      int ref=0,nbOfHit=0;
      for(const int *work2=conn+connIndex[i]+1;work2!=conn+connIndex[i+1];work2++)
        if(*work2>=0)
          {
            ref++;
            if(fastFinder[*work2])
              nbOfHit++;
          }
      if((ref==nbOfHit && fullyIn) || (nbOfHit!=0 && !fullyIn))
        cellIdsKept->pushBackSilent(i);
    }
  cellIdsKeptArr=cellIdsKept.retn();
}

/*!
 * This method is very close too MEDCouplingUMesh::buildPartOfMySelfNode. The difference is that it returns directly ids.
 */
DataArrayInt *MEDCouplingUMesh::getCellIdsLyingOnNodes(const int *begin, const int *end, bool fullyIn) const
{
  DataArrayInt *cellIdsKept=0;
  fillCellIdsToKeepFromNodeIds(begin,end,fullyIn,cellIdsKept);
  cellIdsKept->setName(getName());
  return cellIdsKept;
}

/*!
 * Keeps from 'this' only cells which constituing point id are in the ids specified by ['begin','end').
 * The return newly allocated mesh will share the same coordinates as 'this'.
 * Parameter 'fullyIn' specifies if a cell that has part of its nodes in ids array is kept or not.
 * If 'fullyIn' is true only cells whose ids are \b fully contained in ['begin','end') tab will be kept.
 */
MEDCouplingPointSet *MEDCouplingUMesh::buildPartOfMySelfNode(const int *begin, const int *end, bool fullyIn) const
{
  DataArrayInt *cellIdsKept=0;
  fillCellIdsToKeepFromNodeIds(begin,end,fullyIn,cellIdsKept);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIdsKept2(cellIdsKept);
  return buildPartOfMySelf(cellIdsKept->begin(),cellIdsKept->end(),true);
}

/*!
 * Contrary to MEDCouplingUMesh::buildPartOfMySelfNode method this method builds a mesh with a meshDimension equal to
 * this->getMeshDimension()-1. The return newly allocated mesh will share the same coordinates as 'this'.
 * Parameter 'fullyIn' specifies if a face that has part of its nodes in ids array is kept or not.
 * If 'fullyIn' is true only faces whose ids are \b fully contained in ['begin','end') tab will be kept.
 */
MEDCouplingPointSet *MEDCouplingUMesh::buildFacePartOfMySelfNode(const int *begin, const int *end, bool fullyIn) const
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc,descIndx,revDesc,revDescIndx;
  desc=DataArrayInt::New(); descIndx=DataArrayInt::New(); revDesc=DataArrayInt::New(); revDescIndx=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> subMesh=buildDescendingConnectivity(desc,descIndx,revDesc,revDescIndx);
  desc=0; descIndx=0; revDesc=0; revDescIndx=0;
  return subMesh->buildPartOfMySelfNode(begin,end,fullyIn);
}

/*!
 * This method returns a mesh with meshDim=this->getMeshDimension()-1.
 * This returned mesh contains cells that are linked with one and only one cell of this.
 * @param keepCoords specifies if ParaMEDMEM::MEDCouplingUMesh::zipCoords is called on returned mesh before being returned. If true zipCoords is \b NOT called, if false, zipCoords is called.
 * @return mesh with ref counter equal to 1.
 */
MEDCouplingPointSet *MEDCouplingUMesh::buildBoundaryMesh(bool keepCoords) const
{
  DataArrayInt *desc=DataArrayInt::New();
  DataArrayInt *descIndx=DataArrayInt::New();
  DataArrayInt *revDesc=DataArrayInt::New();
  DataArrayInt *revDescIndx=DataArrayInt::New();
  //
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> meshDM1=buildDescendingConnectivity(desc,descIndx,revDesc,revDescIndx);
  revDesc->decrRef();
  desc->decrRef();
  descIndx->decrRef();
  int nbOfCells=meshDM1->getNumberOfCells();
  const int *revDescIndxC=revDescIndx->getConstPointer();
  std::vector<int> boundaryCells;
  for(int i=0;i<nbOfCells;i++)
    if(revDescIndxC[i+1]-revDescIndxC[i]==1)
      boundaryCells.push_back(i);
  revDescIndx->decrRef();
  MEDCouplingPointSet *ret=meshDM1->buildPartOfMySelf(&boundaryCells[0],&boundaryCells[0]+boundaryCells.size(),keepCoords);
  return ret;
}

/*!
 * This method returns a newly created DataArrayInt instance containing ids of cells located in boundary.
 * A cell is detected to be on boundary if it contains one or more than one face having only one father.
 * This method makes the assumption that 'this' is fully defined (coords,connectivity). If not an exception will be thrown. 
 */
DataArrayInt *MEDCouplingUMesh::findCellIdsOnBoundary() const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descIndx=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx=DataArrayInt::New();
  //
  buildDescendingConnectivity(desc,descIndx,revDesc,revDescIndx)->decrRef();
  desc=(DataArrayInt*)0; descIndx=(DataArrayInt*)0;
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp=revDescIndx->deltaShiftIndex();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> faceIds=tmp->getIdsEqual(1); tmp=(DataArrayInt*)0;
  const int *revDescPtr=revDesc->getConstPointer();
  const int *revDescIndxPtr=revDescIndx->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::vector<bool> ret1(nbOfCells,false);
  int sz=0;
  for(const int *pt=faceIds->begin();pt!=faceIds->end();pt++)
    if(!ret1[revDescPtr[revDescIndxPtr[*pt]]])
      { ret1[revDescPtr[revDescIndxPtr[*pt]]]=true; sz++; }
  //
  DataArrayInt *ret2=DataArrayInt::New();
  ret2->alloc(sz,1);
  int *ret2Ptr=ret2->getPointer();
  sz=0;
  for(std::vector<bool>::const_iterator it=ret1.begin();it!=ret1.end();it++,sz++)
    if(*it)
      *ret2Ptr++=sz;
  ret2->setName("BoundaryCells");
  return ret2;
}

/*!
 * This method find in \b this cells ids that lie on mesh \b otherDimM1OnSameCoords.
 * \b this and \b otherDimM1OnSameCoords have to lie on the same coordinate array pointer. The coherency of that coords array with connectivity
 * of \b this and \b otherDimM1OnSameCoords is not important here because this method works only on connectivity.
 * this->getMeshDimension() - 1 must be equal to otherDimM1OnSameCoords.getMeshDimension()
 *
 * s0 is the cells ids set in \b this lying on at least one node in fetched nodes in \b otherDimM1OnSameCoords.
 * This method method returns cells ids set s = s1 + s2 where :
 * 
 *  - s1 are cells ids in \b this whose dim-1 constituent equals a cell in \b otherDimM1OnSameCoords.
 *  - s2 are cells ids in \b s0 - \b s1 whose at least two neighbors are in s1.
 *
 * \throw if \b otherDimM1OnSameCoords is not part of constituent of \b this, or if coordinate pointer of \b this and \b otherDimM1OnSameCoords
 *        are not same, or if this->getMeshDimension()-1!=otherDimM1OnSameCoords.getMeshDimension()
 *
 * \param [out] cellIdsRk0 a newly allocated array containing cells ids in \b this containg s0 in above algorithm.
 * \param [out] cellIdsRk1 a newly allocated array containing cells ids of s1+s2 \b into \b cellIdsRk0 subset. To get absolute ids of s1+s2 simply invoke
 *              cellIdsRk1->transformWithIndArr(cellIdsRk0->begin(),cellIdsRk0->end());
 */
void MEDCouplingUMesh::findCellIdsLyingOn(const MEDCouplingUMesh& otherDimM1OnSameCoords, DataArrayInt *&cellIdsRk0, DataArrayInt *&cellIdsRk1) const throw(INTERP_KERNEL::Exception)
{
  if(getCoords()!=otherDimM1OnSameCoords.getCoords())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::findCellIdsLyingOn : coordinates pointer are not the same ! Use tryToShareSameCoords method !");
  checkConnectivityFullyDefined();
  otherDimM1OnSameCoords.checkConnectivityFullyDefined();
  if(getMeshDimension()-1!=otherDimM1OnSameCoords.getMeshDimension())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::findCellIdsLyingOn : invalid mesh dimension of input mesh regarding meshdimesion of this !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> fetchedNodeIds1=otherDimM1OnSameCoords.computeFetchedNodeIds();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s0arr=getCellIdsLyingOnNodes(fetchedNodeIds1->begin(),fetchedNodeIds1->end(),false);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> thisPart=static_cast<MEDCouplingUMesh *>(buildPartOfMySelf(s0arr->begin(),s0arr->end(),true));
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descThisPart=DataArrayInt::New(),descIThisPart=DataArrayInt::New(),revDescThisPart=DataArrayInt::New(),revDescIThisPart=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> thisPartConsti=thisPart->buildDescendingConnectivity(descThisPart,descIThisPart,revDescThisPart,revDescIThisPart);
  const int *revDescThisPartPtr=revDescThisPart->getConstPointer(),*revDescIThisPartPtr=revDescIThisPart->getConstPointer();
  DataArrayInt *idsOtherInConsti=0;
  bool b=thisPartConsti->areCellsIncludedIn(&otherDimM1OnSameCoords,2,idsOtherInConsti);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> idsOtherInConstiAuto(idsOtherInConsti);
  if(!b)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::findCellIdsLyingOn : the given mdim-1 mesh in other is not a constituent of this !");
  std::set<int> s1;
  for(const int *idOther=idsOtherInConsti->begin();idOther!=idsOtherInConsti->end();idOther++)
    s1.insert(revDescThisPartPtr+revDescIThisPartPtr[*idOther],revDescThisPartPtr+revDescIThisPartPtr[*idOther+1]);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s1arr_renum1=DataArrayInt::New(); s1arr_renum1->alloc((int)s1.size(),1); std::copy(s1.begin(),s1.end(),s1arr_renum1->getPointer());
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s1Comparr_renum1=s1arr_renum1->buildComplement(s0arr->getNumberOfTuples());
  DataArrayInt *neighThisPart=0,*neighIThisPart=0;
  ComputeNeighborsOfCellsAdv(descThisPart,descIThisPart,revDescThisPart,revDescIThisPart,neighThisPart,neighIThisPart);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> neighThisPartAuto(neighThisPart),neighIThisPartAuto(neighIThisPart);
  ExtractFromIndexedArrays(s1Comparr_renum1->begin(),s1Comparr_renum1->end(),neighThisPart,neighIThisPart,neighThisPart,neighIThisPart);// reuse of neighThisPart and neighIThisPart
  neighThisPartAuto=neighThisPart; neighIThisPartAuto=neighIThisPart;
  RemoveIdsFromIndexedArrays(s1Comparr_renum1->begin(),s1Comparr_renum1->end(),neighThisPart,neighIThisPart);
  neighThisPartAuto=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s2_tmp=neighIThisPart->deltaShiftIndex();
  const int li[2]={0,1};
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s2_renum2=s2_tmp->getIdsNotEqualList(li,li+2);
  s2_renum2->transformWithIndArr(s1Comparr_renum1->begin(),s1Comparr_renum1->end());//s2_renum2==s2_renum1
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s_renum1=DataArrayInt::Aggregate(s2_renum2,s1arr_renum1,0);
  s_renum1->sort();
  //
  cellIdsRk0=s0arr.retn();
  cellIdsRk1=s_renum1.retn();
}

/*!
 * This method computes the skin of \b this. That is to say the consituting meshdim-1 mesh is built and only the boundary subpart is
 * returned. This subpart of meshdim-1 mesh is built using meshdim-1 cells in it shared only one cell in \b this.
 * 
 * \return a newly allocated mesh lying on the same coordinates than \b this. The caller has to deal with returned mesh.
 */
MEDCouplingUMesh *MEDCouplingUMesh::computeSkin() const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descIndx=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx=DataArrayInt::New();
  //
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> meshDM1=buildDescendingConnectivity(desc,descIndx,revDesc,revDescIndx);
  revDesc=0; desc=0; descIndx=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx2=revDescIndx->deltaShiftIndex();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> part=revDescIndx2->getIdsEqual(1);
  return static_cast<MEDCouplingUMesh *>(meshDM1->buildPartOfMySelf(part->begin(),part->end(),true));
}

/*!
 * This methods returns set of nodes in a newly allocated array that the caller has to deal with.
 * The returned nodes ids are those lying on the boundary of \b this.
 */
DataArrayInt *MEDCouplingUMesh::findBoundaryNodes() const
{
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> skin=computeSkin();
  return skin->computeFetchedNodeIds();
}

MEDCouplingUMesh *MEDCouplingUMesh::buildUnstructured() const throw(INTERP_KERNEL::Exception)
{
  incrRef();
  return const_cast<MEDCouplingUMesh *>(this);
}

/*
 * This method renumber 'this' using 'newNodeNumbers' array of size this->getNumberOfNodes.
 * newNbOfNodes specifies the *std::max_element(newNodeNumbers,newNodeNumbers+this->getNumberOfNodes())
 * This value is asked because often known by the caller of this method.
 * This method, contrary to MEDCouplingMesh::renumberCells does NOT conserve the number of nodes before and after.
 *
 * @param newNodeNumbers array specifying the new numbering in old2New convention.
 * @param newNbOfNodes the new number of nodes.
 */
void MEDCouplingUMesh::renumberNodes(const int *newNodeNumbers, int newNbOfNodes)
{
  MEDCouplingPointSet::renumberNodes(newNodeNumbers,newNbOfNodes);
  renumberNodesInConn(newNodeNumbers);
}

/*
 * This method renumber 'this' using 'newNodeNumbers' array of size this->getNumberOfNodes.
 * newNbOfNodes specifies the *std::max_element(newNodeNumbers,newNodeNumbers+this->getNumberOfNodes())
 * This value is asked because often known by the caller of this method.
 * This method, contrary to MEDCouplingMesh::renumberCells does NOT conserve the number of nodes before and after.
 * The difference with ParaMEDMEM::MEDCouplingUMesh::renumberNodes method is in the fact that the barycenter of merged nodes is computed here.
 *
 * @param newNodeNumbers array specifying the new numbering.
 * @param newNbOfNodes the new number of nodes.
 *
 */
void MEDCouplingUMesh::renumberNodes2(const int *newNodeNumbers, int newNbOfNodes)
{
  MEDCouplingPointSet::renumberNodes2(newNodeNumbers,newNbOfNodes);
  renumberNodesInConn(newNodeNumbers);
}

/*!
 * This method expects that \b this and \b otherDimM1OnSameCoords share the same coordinates array.
 * otherDimM1OnSameCoords->getMeshDimension() is expected to be equal to this->getMeshDimension()-1.
 * This method searches for nodes needed to be duplicated. These nodes are nodes fetched by \b otherDimM1OnSameCoords which are not part of the boundary of \b otherDimM1OnSameCoords.
 * If a node is in the boundary of \b this \b and in the boundary of \b otherDimM1OnSameCoords this node is considerd as needed to be duplicated.
 * When the set of node ids \b nodeIdsToDuplicate is computed, cell ids in \b this is searched so that their connectivity includes at least 1 node in \b nodeIdsToDuplicate.
 *
 * \param [in] otherDimM1OnSameCoords a mesh lying on the same coords than \b this and with a mesh dimension equal to those of \b this minus 1. WARNING this input
 *             parameter is altered during the call.
 * \param [out] nodeIdsToDuplicate node ids needed to be duplicated following the algorithm explain above.
 * \param [out] cellIdsNeededToBeRenum cell ids in \b this in which the renumber of nodes should be performed.
 * \param [out] cellIdsNotModified cell ids int \b this that lies on \b otherDimM1OnSameCoords mesh whose connectivity do \b not need to be modified as it is the case for \b cellIdsNeededToBeRenum.
 *
 * \warning This method modifies param \b otherDimM1OnSameCoords (for speed reasons).
 */
void MEDCouplingUMesh::findNodesToDuplicate(const MEDCouplingUMesh& otherDimM1OnSameCoords, DataArrayInt *& nodeIdsToDuplicate,
                                            DataArrayInt *& cellIdsNeededToBeRenum, DataArrayInt *& cellIdsNotModified) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  otherDimM1OnSameCoords.checkFullyDefined();
  if(getCoords()!=otherDimM1OnSameCoords.getCoords())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::findNodesToDuplicate : meshes do not share the same coords array !");
  if(otherDimM1OnSameCoords.getMeshDimension()!=getMeshDimension()-1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::findNodesToDuplicate : the mesh given in other parameter must have this->getMeshDimension()-1 !");
  DataArrayInt *cellIdsRk0=0,*cellIdsRk1=0;
  findCellIdsLyingOn(otherDimM1OnSameCoords,cellIdsRk0,cellIdsRk1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIdsRk0Auto(cellIdsRk0),cellIdsRk1Auto(cellIdsRk1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s0=cellIdsRk1->buildComplement(cellIdsRk0->getNumberOfTuples());
  s0->transformWithIndArr(cellIdsRk0Auto->begin(),cellIdsRk0Auto->end());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m0Part=static_cast<MEDCouplingUMesh *>(buildPartOfMySelf(s0->begin(),s0->end(),true));
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s1=m0Part->computeFetchedNodeIds();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s2=otherDimM1OnSameCoords.computeFetchedNodeIds();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> s3=s2->buildSubstraction(s1);
  cellIdsRk1->transformWithIndArr(cellIdsRk0Auto->begin(),cellIdsRk0Auto->end());
  //
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m0Part2=static_cast<MEDCouplingUMesh *>(buildPartOfMySelf(cellIdsRk1->begin(),cellIdsRk1->end(),true));
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc00=DataArrayInt::New(),descI00=DataArrayInt::New(),revDesc00=DataArrayInt::New(),revDescI00=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m01=m0Part2->buildDescendingConnectivity(desc00,descI00,revDesc00,revDescI00);
  DataArrayInt *idsTmp=0;
  bool b=m01->areCellsIncludedIn(&otherDimM1OnSameCoords,2,idsTmp);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ids(idsTmp);
  if(!b)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::findNodesToDuplicate : the given mdim-1 mesh in other is not a constituent of this !");
  MEDCouplingUMesh::RemoveIdsFromIndexedArrays(ids->begin(),ids->end(),desc00,descI00);
  DataArrayInt *tmp0=0,*tmp1=0;
  ComputeNeighborsOfCellsAdv(desc00,descI00,revDesc00,revDescI00,tmp0,tmp1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> neigh00(tmp0);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> neighI00(tmp1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellsToModifyConn0_torenum=MEDCouplingUMesh::ComputeSpreadZoneGradually(neigh00,neighI00);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellsToModifyConn1_torenum=cellsToModifyConn0_torenum->buildComplement(neighI00->getNumberOfTuples()-1);
  cellsToModifyConn0_torenum->transformWithIndArr(cellIdsRk1->begin(),cellIdsRk1->end());
  cellsToModifyConn1_torenum->transformWithIndArr(cellIdsRk1->begin(),cellIdsRk1->end());
  //
  cellIdsNeededToBeRenum=cellsToModifyConn0_torenum.retn();
  cellIdsNotModified=cellsToModifyConn1_torenum.retn();
  nodeIdsToDuplicate=s3.retn();
}

/*!
 * This method operates a modification of the connectivity and coords in \b this.
 * Every time that a node id in [\b nodeIdsToDuplicateBg, \b nodeIdsToDuplicateEnd) will append in nodal connectivity of \b this 
 * its ids will be modified to id this->getNumberOfNodes()+std::distance(nodeIdsToDuplicateBg,std::find(nodeIdsToDuplicateBg,nodeIdsToDuplicateEnd,id)).
 * More explicitely the renumber array in nodes is not explicitely given in old2new to avoid to build a big array of renumbering whereas typically few node ids needs to be
 * renumbered. The node id nodeIdsToDuplicateBg[0] will have id this->getNumberOfNodes()+0, node id nodeIdsToDuplicateBg[1] will have id this->getNumberOfNodes()+1,
 * node id nodeIdsToDuplicateBg[2] will have id this->getNumberOfNodes()+2...
 * 
 * As a consequence nodal connectivity array length will remain unchanged by this method, and nodal connectivity index array will remain unchanged by this method.
 * 
 * \param [in] nodeIdsToDuplicateBg begin of node ids (included) to be duplicated in connectivity only
 * \param [in] nodeIdsToDuplicateEnd end of node ids (excluded) to be duplicated in connectivity only
 */
void MEDCouplingUMesh::duplicateNodes(const int *nodeIdsToDuplicateBg, const int *nodeIdsToDuplicateEnd) throw(INTERP_KERNEL::Exception)
{
  int nbOfNodes=getNumberOfNodes();
  duplicateNodesInCoords(nodeIdsToDuplicateBg,nodeIdsToDuplicateEnd);
  duplicateNodesInConn(nodeIdsToDuplicateBg,nodeIdsToDuplicateEnd,nbOfNodes);
}

/*!
 * This method renumbers nodes \b in \b connectivity \b only \b without \b any \b reference \b to \b coords.
 * This method performs no check on the fact that new coordinate ids are valid. \b Use \b it \b with \b care !
 * This method is an generalization of \ref ParaMEDMEM::MEDCouplingUMesh::shiftNodeNumbersInConn "shiftNodeNumbersInConn method".
 * @param [in] newNodeNumbers in old2New convention
 */
void MEDCouplingUMesh::renumberNodesInConn(const int *newNodeNumbersO2N)
{
  checkConnectivityFullyDefined();
  int *conn=getNodalConnectivity()->getPointer();
  const int *connIndex=getNodalConnectivityIndex()->getConstPointer();
  int nbOfCells=getNumberOfCells();
  for(int i=0;i<nbOfCells;i++)
    for(int iconn=connIndex[i]+1;iconn!=connIndex[i+1];iconn++)
      {
        int& node=conn[iconn];
        if(node>=0)//avoid polyhedron separator
          {
            node=newNodeNumbersO2N[node];
          }
      }
  _nodal_connec->declareAsNew();
  updateTime();
}

/*!
 * This method renumbers nodes \b in \b connectivity \b only \b without \b any \b reference \b to \b coords.
 * This method performs no check on the fact that new coordinate ids are valid. \b Use \b it \b with \b care !
 * This method is an specialization of \ref ParaMEDMEM::MEDCouplingUMesh::renumberNodesInConn "renumberNodesInConn method".
 * 
 * @param [in] delta specifies the shift size applied to nodeId in nodal connectivity in \b this.
 */
void MEDCouplingUMesh::shiftNodeNumbersInConn(int delta) throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  int *conn=getNodalConnectivity()->getPointer();
  const int *connIndex=getNodalConnectivityIndex()->getConstPointer();
  int nbOfCells=getNumberOfCells();
  for(int i=0;i<nbOfCells;i++)
    for(int iconn=connIndex[i]+1;iconn!=connIndex[i+1];iconn++)
      {
        int& node=conn[iconn];
        if(node>=0)//avoid polyhedron separator
          {
            node+=delta;
          }
      }
  _nodal_connec->declareAsNew();
  updateTime();
}

/*!
 * This method operates a modification of the connectivity in \b this.
 * Coordinates are \b NOT considered here and will remain unchanged by this method. this->_coords can ever been null for the needs of this method.
 * Every time that a node id in [\b nodeIdsToDuplicateBg, \b nodeIdsToDuplicateEnd) will append in nodal connectivity of \b this 
 * its ids will be modified to id offset+std::distance(nodeIdsToDuplicateBg,std::find(nodeIdsToDuplicateBg,nodeIdsToDuplicateEnd,id)).
 * More explicitely the renumber array in nodes is not explicitely given in old2new to avoid to build a big array of renumbering whereas typically few node ids needs to be
 * renumbered. The node id nodeIdsToDuplicateBg[0] will have id offset+0, node id nodeIdsToDuplicateBg[1] will have id offset+1,
 * node id nodeIdsToDuplicateBg[2] will have id offset+2...
 * 
 * As a consequence nodal connectivity array length will remain unchanged by this method, and nodal connectivity index array will remain unchanged by this method.
 * As an another consequense after the call of this method \b this can be transiently non cohrent.
 * 
 * \param [in] nodeIdsToDuplicateBg begin of node ids (included) to be duplicated in connectivity only
 * \param [in] nodeIdsToDuplicateEnd end of node ids (excluded) to be duplicated in connectivity only
 * \param [in] offset the offset applied to all node ids in connectivity that are in [nodeIdsToDuplicateBg,nodeIdsToDuplicateEnd). 
 */
void MEDCouplingUMesh::duplicateNodesInConn(const int *nodeIdsToDuplicateBg, const int *nodeIdsToDuplicateEnd, int offset) throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  std::map<int,int> m;
  int val=offset;
  for(const int *work=nodeIdsToDuplicateBg;work!=nodeIdsToDuplicateEnd;work++,val++)
    m[*work]=val;
  int *conn=getNodalConnectivity()->getPointer();
  const int *connIndex=getNodalConnectivityIndex()->getConstPointer();
  int nbOfCells=getNumberOfCells();
  for(int i=0;i<nbOfCells;i++)
    for(int iconn=connIndex[i]+1;iconn!=connIndex[i+1];iconn++)
      {
        int& node=conn[iconn];
        if(node>=0)//avoid polyhedron separator
          {
            std::map<int,int>::iterator it=m.find(node);
            if(it!=m.end())
              node=(*it).second;
          }
      }
  updateTime();
}

/*!
 * This method renumbers cells of 'this' using the array specified by [old2NewBg;old2NewBg+getNumberOfCells())
 *
 * Contrary to MEDCouplingPointSet::renumberNodes, this method makes a permutation without any fuse of cell.
 * After the call of this method the number of cells remains the same as before.
 *
 * If 'check' equals true the method will check that any elements in [old2NewBg;old2NewEnd) is unique ; if not
 * an INTERP_KERNEL::Exception will be thrown. When 'check' equals true [old2NewBg;old2NewEnd) is not expected to
 * be strictly in [0;this->getNumberOfCells()).
 *
 * If 'check' equals false the method will not check the content of [old2NewBg;old2NewEnd).
 * To avoid any throw of SIGSEGV when 'check' equals false, the elements in [old2NewBg;old2NewEnd) should be unique and
 * should be contained in[0;this->getNumberOfCells()).
 * 
 * \param [in] old2NewBg is expected to be a dynamically allocated pointer of size at least equal to this->getNumberOfCells()
 */
void MEDCouplingUMesh::renumberCells(const int *old2NewBg, bool check) throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  int nbCells=getNumberOfCells();
  const int *array=old2NewBg;
  if(check)
    array=DataArrayInt::CheckAndPreparePermutation(old2NewBg,old2NewBg+nbCells);
  //
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  newConn->alloc(_nodal_connec->getNumberOfTuples(),_nodal_connec->getNumberOfComponents());
  newConn->copyStringInfoFrom(*_nodal_connec);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConnI->alloc(_nodal_connec_index->getNumberOfTuples(),_nodal_connec_index->getNumberOfComponents());
  newConnI->copyStringInfoFrom(*_nodal_connec_index);
  //
  int *newC=newConn->getPointer();
  int *newCI=newConnI->getPointer();
  int loc=0;
  newCI[0]=loc;
  for(int i=0;i<nbCells;i++)
    {
      std::size_t pos=std::distance(array,std::find(array,array+nbCells,i));
      int nbOfElts=connI[pos+1]-connI[pos];
      newC=std::copy(conn+connI[pos],conn+connI[pos+1],newC);
      loc+=nbOfElts;
      newCI[i+1]=loc;
    }
  //
  setConnectivity(newConn,newConnI);
  if(check)
    delete [] const_cast<int *>(array);
}

/*!
 * Given a boundary box 'bbox' returns elements 'elems' contained in this 'bbox'.
 * Warning 'elems' is incremented during the call so if elems is not empty before call returned elements will be
 * added in 'elems' parameter.
 */
DataArrayInt *MEDCouplingUMesh::getCellsInBoundingBox(const double *bbox, double eps) const
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> elems=DataArrayInt::New(); elems->alloc(0,1);
  if(getMeshDimension()==-1)
    {
      elems->pushBackSilent(0);
      return elems.retn();
    }
  int dim=getSpaceDimension();
  INTERP_KERNEL::AutoPtr<double> elem_bb=new double[2*dim];
  const int* conn      = getNodalConnectivity()->getConstPointer();
  const int* conn_index= getNodalConnectivityIndex()->getConstPointer();
  const double* coords = getCoords()->getConstPointer();
  int nbOfCells=getNumberOfCells();
  for ( int ielem=0; ielem<nbOfCells;ielem++ )
    {
      for (int i=0; i<dim; i++)
        {
          elem_bb[i*2]=std::numeric_limits<double>::max();
          elem_bb[i*2+1]=-std::numeric_limits<double>::max();
        }

      for (int inode=conn_index[ielem]+1; inode<conn_index[ielem+1]; inode++)//+1 due to offset of cell type.
        {
          int node= conn[inode];
          if(node>=0)//avoid polyhedron separator
            {
              for (int idim=0; idim<dim; idim++)
                {
                  if ( coords[node*dim+idim] < elem_bb[idim*2] )
                    {
                      elem_bb[idim*2] = coords[node*dim+idim] ;
                    }
                  if ( coords[node*dim+idim] > elem_bb[idim*2+1] )
                    {
                      elem_bb[idim*2+1] = coords[node*dim+idim] ;
                    }
                }
            }
        }
      if (intersectsBoundingBox(elem_bb, bbox, dim, eps))
        elems->pushBackSilent(ielem);
    }
  return elems.retn();
}

/*!
 * Given a boundary box 'bbox' returns elements 'elems' contained in this 'bbox' or touching 'bbox' (within 'eps' distance).
 * Warning 'elems' is incremented during the call so if elems is not empty before call returned elements will be
 * added in 'elems' parameter.
 */
DataArrayInt *MEDCouplingUMesh::getCellsInBoundingBox(const INTERP_KERNEL::DirectedBoundingBox& bbox, double eps)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> elems=DataArrayInt::New(); elems->alloc(0,1);
  if(getMeshDimension()==-1)
    {
      elems->pushBackSilent(0);
      return elems.retn();
    }
  int dim=getSpaceDimension();
  INTERP_KERNEL::AutoPtr<double> elem_bb=new double[2*dim];
  const int* conn      = getNodalConnectivity()->getConstPointer();
  const int* conn_index= getNodalConnectivityIndex()->getConstPointer();
  const double* coords = getCoords()->getConstPointer();
  int nbOfCells=getNumberOfCells();
  for ( int ielem=0; ielem<nbOfCells;ielem++ )
    {
      for (int i=0; i<dim; i++)
        {
          elem_bb[i*2]=std::numeric_limits<double>::max();
          elem_bb[i*2+1]=-std::numeric_limits<double>::max();
        }

      for (int inode=conn_index[ielem]+1; inode<conn_index[ielem+1]; inode++)//+1 due to offset of cell type.
        {
          int node= conn[inode];
          if(node>=0)//avoid polyhedron separator
            {
              for (int idim=0; idim<dim; idim++)
                {
                  if ( coords[node*dim+idim] < elem_bb[idim*2] )
                    {
                      elem_bb[idim*2] = coords[node*dim+idim] ;
                    }
                  if ( coords[node*dim+idim] > elem_bb[idim*2+1] )
                    {
                      elem_bb[idim*2+1] = coords[node*dim+idim] ;
                    }
                }
            }
        }
      if(intersectsBoundingBox(bbox, elem_bb, dim, eps))
        elems->pushBackSilent(ielem);
    }
  return elems.retn();
}

/*!
 * Returns the cell type of cell with id 'cellId'.
 */
INTERP_KERNEL::NormalizedCellType MEDCouplingUMesh::getTypeOfCell(int cellId) const
{
  const int *ptI=_nodal_connec_index->getConstPointer();
  const int *pt=_nodal_connec->getConstPointer();
  if(cellId>=0 && cellId<_nodal_connec_index->getNbOfElems()-1)
    return (INTERP_KERNEL::NormalizedCellType) pt[ptI[cellId]];
  else
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::getTypeOfCell : Requesting type of cell #" << cellId << " but it should be in [0," << _nodal_connec_index->getNbOfElems()-1 << ") !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
}

/*!
 * This method returns a newly allocated array containing cell ids (ascendingly sorted) whose geometric type are equal to type.
 * This method throws an INTERP_KERNEL::Exception if meshdimension of \b this is not equal to those of \b type.
 * The coordinates array is not considered here.
 *
 * \param [in] type the geometric type
 * \return cell ids in this having geometric type \a type.
 */
DataArrayInt *MEDCouplingUMesh::giveCellsWithType(INTERP_KERNEL::NormalizedCellType type) const throw(INTERP_KERNEL::Exception)
{
  
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  ret->alloc(0,1);
  checkConnectivityFullyDefined();
  int nbCells=getNumberOfCells();
  int mdim=getMeshDimension();
  const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
  if(mdim!=(int)cm.getDimension())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::giveCellsWithType : Mismatch between mesh dimension and dimension of the cell !");
  const int *ptI=_nodal_connec_index->getConstPointer();
  const int *pt=_nodal_connec->getConstPointer();
  for(int i=0;i<nbCells;i++)
    {
      if((INTERP_KERNEL::NormalizedCellType)pt[ptI[i]]==type)
        ret->pushBackSilent(i);
    }
  return ret.retn();
}

/*!
 * Returns nb of cells having the geometric type 'type'.
 */
int MEDCouplingUMesh::getNumberOfCellsWithType(INTERP_KERNEL::NormalizedCellType type) const
{
  const int *ptI=_nodal_connec_index->getConstPointer();
  const int *pt=_nodal_connec->getConstPointer();
  int nbOfCells=getNumberOfCells();
  int ret=0;
  for(int i=0;i<nbOfCells;i++)
    if((INTERP_KERNEL::NormalizedCellType) pt[ptI[i]]==type)
      ret++;
  return ret;
}

/*!
 * Appends the nodal connectivity in 'conn' of cell with id 'cellId'.
 * All elements added in conn can be used by MEDCouplingUMesh::getCoordinatesOfNode method.
 * That is to say -1 separator is omitted in returned conn.
 */
void MEDCouplingUMesh::getNodeIdsOfCell(int cellId, std::vector<int>& conn) const
{
  const int *ptI=_nodal_connec_index->getConstPointer();
  const int *pt=_nodal_connec->getConstPointer();
  for(const int *w=pt+ptI[cellId]+1;w!=pt+ptI[cellId+1];w++)
    if(*w>=0)
      conn.push_back(*w);
}

std::string MEDCouplingUMesh::simpleRepr() const
{
  static const char msg0[]="No coordinates specified !";
  std::ostringstream ret;
  ret << "Unstructured mesh with name : \"" << getName() << "\"\n";
  ret << "Description of mesh : \"" << getDescription() << "\"\n";
  int tmpp1,tmpp2;
  double tt=getTime(tmpp1,tmpp2);
  ret << "Time attached to the mesh [unit] : " << tt << " [" << getTimeUnit() << "]\n";
  ret << "Iteration : " << tmpp1  << " Order : " << tmpp2 << "\n";
  ret << "Mesh dimension : " << _mesh_dim << "\nSpace dimension : ";
  if(_coords!=0)
    {
      const int spaceDim=getSpaceDimension();
      ret << spaceDim << "\nInfo attached on space dimension : ";
      for(int i=0;i<spaceDim;i++)
        ret << "\"" << _coords->getInfoOnComponent(i) << "\" ";
      ret << "\n";
    }
  else
    ret << msg0 << "\n";
  ret << "Number of nodes : ";
  if(_coords!=0)
    ret << getNumberOfNodes() << "\n";
  else
    ret << msg0 << "\n";
  ret << "Number of cells : ";
  if(_nodal_connec!=0 && _nodal_connec_index!=0)
    ret << getNumberOfCells() << "\n";
  else
    ret << "No connectivity specified !" << "\n";
  ret << "Cell types present : ";
  for(std::set<INTERP_KERNEL::NormalizedCellType>::const_iterator iter=_types.begin();iter!=_types.end();iter++)
    {
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(*iter);
      ret << cm.getRepr() << " ";
    }
  ret << "\n";
  return ret.str();
}

std::string MEDCouplingUMesh::advancedRepr() const
{
  std::ostringstream ret;
  ret << simpleRepr();
  ret << "\nCoordinates array : \n___________________\n\n";
  if(_coords)
    _coords->reprWithoutNameStream(ret);
  else
    ret << "No array set !\n";
  ret << "\n\nConnectivity arrays : \n_____________________\n\n";
  reprConnectivityOfThisLL(ret);
  return ret.str();
}

/*!
 * This method returns a C++ code that is a dump of \a this.
 * This method will throw if this is not fully defined.
 */
std::string MEDCouplingUMesh::cppRepr() const throw(INTERP_KERNEL::Exception)
{
  static const char coordsName[]="coords";
  static const char connName[]="conn";
  static const char connIName[]="connI";
  checkFullyDefined();
  std::ostringstream ret; ret << "// coordinates" << std::endl;
  _coords->reprCppStream(coordsName,ret); ret << std::endl << "// connectivity" << std::endl;
  _nodal_connec->reprCppStream(connName,ret); ret << std::endl;
  _nodal_connec_index->reprCppStream(connIName,ret); ret << std::endl;
  ret << "MEDCouplingUMesh *mesh=MEDCouplingUMesh::New(\"" << getName() << "\"," << getMeshDimension() << ");" << std::endl;
  ret << "mesh->setCoords(" << coordsName << ");" << std::endl;
  ret << "mesh->setConnectivity(" << connName << "," << connIName << ",true);" << std::endl;
  ret << coordsName << "->decrRef(); " << connName << "->decrRef(); " << connIName << "->decrRef();" << std::endl;
  return ret.str();
}

std::string MEDCouplingUMesh::reprConnectivityOfThis() const
{
  std::ostringstream ret;
  reprConnectivityOfThisLL(ret);
  return ret.str();
}

/*!
 * This method builds a newly allocated instance (with the same name than 'this') that the caller has the responsability to deal with.
 * This method returns an instance with all arrays allocated (connectivity, connectivity index, coordinates)
 * but with length of these arrays set to 0. It allows to define an "empty" mesh (with nor cells nor nodes but compliant with
 * some algos).
 * 
 * This method expects that 'this' has a mesh dimension set and higher or equal to 0. If not an exception will be thrown.
 * This method analyzes the 3 arrays of 'this'. For each the following behaviour is done : if the array is null a newly one is created
 * with number of tuples set to 0, if not the array is taken as this in the returned instance.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildSetInstanceFromThis(int spaceDim) const throw(INTERP_KERNEL::Exception)
{
  int mdim=getMeshDimension();
  if(mdim<0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSetInstanceFromThis : invalid mesh dimension ! Should be >= 0 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New(getName(),mdim);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp1,tmp2;
  bool needToCpyCT=true;
  if(!_nodal_connec)
    {
      tmp1=DataArrayInt::New(); tmp1->alloc(0,1);
      needToCpyCT=false;
    }
  else
    {
      tmp1=_nodal_connec;
      tmp1->incrRef();
    }
  if(!_nodal_connec_index)
    {
      tmp2=DataArrayInt::New(); tmp2->alloc(1,1); tmp2->setIJ(0,0,0);
      needToCpyCT=false;
    }
  else
    {
      tmp2=_nodal_connec_index;
      tmp2->incrRef();
    }
  ret->setConnectivity(tmp1,tmp2,false);
  if(needToCpyCT)
    ret->_types=_types;
  if(!_coords)
    {
      MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coords=DataArrayDouble::New(); coords->alloc(0,spaceDim);
      ret->setCoords(coords);
    }
  else
    ret->setCoords(_coords);
  return ret.retn();
}

void MEDCouplingUMesh::reprConnectivityOfThisLL(std::ostringstream& stream) const
{
  if(_nodal_connec!=0 && _nodal_connec_index!=0)
    {
      int nbOfCells=getNumberOfCells();
      const int *c=_nodal_connec->getConstPointer();
      const int *ci=_nodal_connec_index->getConstPointer();
      for(int i=0;i<nbOfCells;i++)
        {
          const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)c[ci[i]]);
          stream << "Cell #" << i << " " << cm.getRepr() << " : ";
          std::copy(c+ci[i]+1,c+ci[i+1],std::ostream_iterator<int>(stream," "));
          stream << "\n";
        }
    }
  else
    stream << "Connectivity not defined !\n";
}

int MEDCouplingUMesh::getNumberOfNodesInCell(int cellId) const
{
  const int *ptI=_nodal_connec_index->getConstPointer();
  const int *pt=_nodal_connec->getConstPointer();
  if(pt[ptI[cellId]]!=INTERP_KERNEL::NORM_POLYHED)
    return ptI[cellId+1]-ptI[cellId]-1;
  else
    return (int)std::count_if(pt+ptI[cellId]+1,pt+ptI[cellId+1],std::bind2nd(std::not_equal_to<int>(),-1));
}

/*!
 * This method is equivalent to MEDCouplingUMesh::getAllTypes excecpt that it returns only types of submesh which cell ids are in [begin,end).
 * This method avoids to compute explicitely submesh to get its types.
 */
std::set<INTERP_KERNEL::NormalizedCellType> MEDCouplingUMesh::getTypesOfPart(const int *begin, const int *end) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  std::set<INTERP_KERNEL::NormalizedCellType> ret;
  const int *conn=_nodal_connec->getConstPointer();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  for(const int *w=begin;w!=end;w++)
    ret.insert((INTERP_KERNEL::NormalizedCellType)conn[connIndex[*w]]);
  return ret;
}

/*!
 * Method reserved for advanced users having prepared their connectivity before.
 * Arrays 'conn' and 'connIndex' will be aggregated without any copy and their counter will be incremented.
 */
void MEDCouplingUMesh::setConnectivity(DataArrayInt *conn, DataArrayInt *connIndex, bool isComputingTypes)
{
  DataArrayInt::SetArrayIn(conn,_nodal_connec);
  DataArrayInt::SetArrayIn(connIndex,_nodal_connec_index);
  if(isComputingTypes)
    computeTypes();
  declareAsNew();
}

/*!
 * Copy constructor. If 'deepCpy' is false 'this' is a shallow copy of other.
 * If 'deeCpy' is true all arrays (coordinates and connectivities) are deeply copied.
 */
MEDCouplingUMesh::MEDCouplingUMesh(const MEDCouplingUMesh& other, bool deepCopy):MEDCouplingPointSet(other,deepCopy),_mesh_dim(other._mesh_dim),
                                                                                 _nodal_connec(0),_nodal_connec_index(0),
                                                                                _types(other._types)
{
  if(other._nodal_connec)
    _nodal_connec=other._nodal_connec->performCpy(deepCopy);
  if(other._nodal_connec_index)
    _nodal_connec_index=other._nodal_connec_index->performCpy(deepCopy);
}

MEDCouplingUMesh::~MEDCouplingUMesh()
{
  if(_nodal_connec)
    _nodal_connec->decrRef();
  if(_nodal_connec_index)
    _nodal_connec_index->decrRef();
}

/*!
 * This method recomputes all cell types of 'this'.
 */
void MEDCouplingUMesh::computeTypes()
{
  if(_nodal_connec && _nodal_connec_index)
    {
      _types.clear();
      const int *conn=_nodal_connec->getConstPointer();
      const int *connIndex=_nodal_connec_index->getConstPointer();
      int nbOfElem=_nodal_connec_index->getNbOfElems()-1;
      if (nbOfElem > 0)
        for(const int *pt=connIndex;pt !=connIndex+nbOfElem;pt++)
          _types.insert((INTERP_KERNEL::NormalizedCellType)conn[*pt]);
    }
}

/*!
 * This method checks that all arrays are set. If yes nothing done if no an exception is thrown.
 */
void MEDCouplingUMesh::checkFullyDefined() const throw(INTERP_KERNEL::Exception)
{
  if(!_nodal_connec_index || !_nodal_connec || !_coords)
    throw INTERP_KERNEL::Exception("Reverse nodal connectivity computation requires full connectivity and coordinates set in unstructured mesh.");
}

/*!
 * This method checks that all connectivity arrays are set. If yes nothing done if no an exception is thrown.
 */
void MEDCouplingUMesh::checkConnectivityFullyDefined() const throw(INTERP_KERNEL::Exception)
{
  if(!_nodal_connec_index || !_nodal_connec)
    throw INTERP_KERNEL::Exception("Reverse nodal connectivity computation requires full connectivity set in unstructured mesh.");
}

int MEDCouplingUMesh::getNumberOfCells() const
{ 
  if(_nodal_connec_index)
    return _nodal_connec_index->getNumberOfTuples()-1;
  else
    if(_mesh_dim==-1)
      return 1;
    else
      throw INTERP_KERNEL::Exception("Unable to get number of cells because no connectivity specified !");
}

int MEDCouplingUMesh::getMeshDimension() const
{
  if(_mesh_dim<-1)
    throw INTERP_KERNEL::Exception("No mesh dimension specified !");
  return _mesh_dim;
}

/*!
 * This method is for test reason. Normally the integer returned is not useable by user.
 */
int MEDCouplingUMesh::getMeshLength() const
{
  return _nodal_connec->getNbOfElems();
}

/*!
 * First step of serialization process. Used by ParaMEDMEM and MEDCouplingCorba to transfert data between process.
 */
void MEDCouplingUMesh::getTinySerializationInformation(std::vector<double>& tinyInfoD, std::vector<int>& tinyInfo, std::vector<std::string>& littleStrings) const
{
  MEDCouplingPointSet::getTinySerializationInformation(tinyInfoD,tinyInfo,littleStrings);
  tinyInfo.push_back(getMeshDimension());
  tinyInfo.push_back(getNumberOfCells());
  if(_nodal_connec)
    tinyInfo.push_back(getMeshLength());
  else
    tinyInfo.push_back(-1);
}

/*!
 * First step of unserialization process.
 */
bool MEDCouplingUMesh::isEmptyMesh(const std::vector<int>& tinyInfo) const
{
  return tinyInfo[6]<=0;
}

/*!
 * Second step of serialization process.
 * @param tinyInfo must be equal to the result given by getTinySerializationInformation method.
 */
void MEDCouplingUMesh::resizeForUnserialization(const std::vector<int>& tinyInfo, DataArrayInt *a1, DataArrayDouble *a2, std::vector<std::string>& littleStrings) const
{
  MEDCouplingPointSet::resizeForUnserialization(tinyInfo,a1,a2,littleStrings);
  if(tinyInfo[5]!=-1)
    a1->alloc(tinyInfo[7]+tinyInfo[6]+1,1);
}

/*!
 * Third and final step of serialization process.
 */
void MEDCouplingUMesh::serialize(DataArrayInt *&a1, DataArrayDouble *&a2) const
{
  MEDCouplingPointSet::serialize(a1,a2);
  if(getMeshDimension()>-1)
    {
      a1=DataArrayInt::New();
      a1->alloc(getMeshLength()+getNumberOfCells()+1,1);
      int *ptA1=a1->getPointer();
      const int *conn=getNodalConnectivity()->getConstPointer();
      const int *index=getNodalConnectivityIndex()->getConstPointer();
      ptA1=std::copy(index,index+getNumberOfCells()+1,ptA1);
      std::copy(conn,conn+getMeshLength(),ptA1);
    }
  else
    a1=0;
}

/*!
 * Second and final unserialization process.
 * @param tinyInfo must be equal to the result given by getTinySerializationInformation method.
 */
void MEDCouplingUMesh::unserialization(const std::vector<double>& tinyInfoD, const std::vector<int>& tinyInfo, const DataArrayInt *a1, DataArrayDouble *a2, const std::vector<std::string>& littleStrings)
{
  MEDCouplingPointSet::unserialization(tinyInfoD,tinyInfo,a1,a2,littleStrings);
  setMeshDimension(tinyInfo[5]);
  if(tinyInfo[7]!=-1)
    {
      // Connectivity
      const int *recvBuffer=a1->getConstPointer();
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> myConnecIndex=DataArrayInt::New();
      myConnecIndex->alloc(tinyInfo[6]+1,1);
      std::copy(recvBuffer,recvBuffer+tinyInfo[6]+1,myConnecIndex->getPointer());
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> myConnec=DataArrayInt::New();
      myConnec->alloc(tinyInfo[7],1);
      std::copy(recvBuffer+tinyInfo[6]+1,recvBuffer+tinyInfo[6]+1+tinyInfo[7],myConnec->getPointer());
      setConnectivity(myConnec, myConnecIndex);
    }
}

/*!
 * This is the low algorithm of MEDCouplingUMesh::buildPartOfMySelf2.
 * CellIds are given using range specified by a start an end and step.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildPartOfMySelfKeepCoords2(int start, int end, int step) const
{
  checkFullyDefined();
  int ncell=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New();
  ret->_mesh_dim=_mesh_dim;
  ret->setCoords(_coords);
  int newNbOfCells=DataArray::GetNumberOfItemGivenBESRelative(start,end,step,"MEDCouplingUMesh::buildPartOfMySelfKeepCoords2 : ");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New(); newConnI->alloc(newNbOfCells+1,1);
  int *newConnIPtr=newConnI->getPointer(); *newConnIPtr=0;
  int work=start;
  const int *conn=_nodal_connec->getConstPointer();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  for(int i=0;i<newNbOfCells;i++,newConnIPtr++,work+=step)
    {
      if(work>=0 && work<ncell)
        {
          newConnIPtr[1]=newConnIPtr[0]+connIndex[work+1]-connIndex[work];
        }
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::buildPartOfMySelfKeepCoords2 : On pos #" << i << " input cell id =" << work << " should be in [0," << ncell << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New(); newConn->alloc(newConnIPtr[0],1);
  int *newConnPtr=newConn->getPointer();
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  work=start;
  for(int i=0;i<newNbOfCells;i++,newConnIPtr++,work+=step)
    {
      types.insert((INTERP_KERNEL::NormalizedCellType)conn[connIndex[work]]);
      newConnPtr=std::copy(conn+connIndex[work],conn+connIndex[work+1],newConnPtr);
    }
  ret->setConnectivity(newConn,newConnI,false);
  ret->_types=types;
  ret->copyTinyInfoFrom(this);
  return ret.retn();
}

/*!
 * This is the low algorithm of MEDCouplingUMesh::buildPartOfMySelf.
 * Keeps from 'this' only cells which constituing point id are in the ids specified by ['begin','end').
 * The return newly allocated mesh will share the same coordinates as 'this'.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildPartOfMySelfKeepCoords(const int *begin, const int *end) const
{
  checkFullyDefined();
  int ncell=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New();
  ret->_mesh_dim=_mesh_dim;
  ret->setCoords(_coords);
  std::size_t nbOfElemsRet=std::distance(begin,end);
  int *connIndexRet=new int[nbOfElemsRet+1];
  connIndexRet[0]=0;
  const int *conn=_nodal_connec->getConstPointer();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  int newNbring=0;
  for(const int *work=begin;work!=end;work++,newNbring++)
    {
      if(*work>=0 && *work<ncell)
        connIndexRet[newNbring+1]=connIndexRet[newNbring]+connIndex[*work+1]-connIndex[*work];
      else
        {
          delete [] connIndexRet;
          std::ostringstream oss; oss << "MEDCouplingUMesh::buildPartOfMySelfKeepCoords : On pos #" << std::distance(begin,work) << " input cell id =" << *work << " should be in [0," << ncell << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  int *connRet=new int[connIndexRet[nbOfElemsRet]];
  int *connRetWork=connRet;
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  for(const int *work=begin;work!=end;work++)
    {
      types.insert((INTERP_KERNEL::NormalizedCellType)conn[connIndex[*work]]);
      connRetWork=std::copy(conn+connIndex[*work],conn+connIndex[*work+1],connRetWork);
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> connRetArr=DataArrayInt::New();
  connRetArr->useArray(connRet,true,CPP_DEALLOC,connIndexRet[nbOfElemsRet],1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> connIndexRetArr=DataArrayInt::New();
  connIndexRetArr->useArray(connIndexRet,true,CPP_DEALLOC,(int)nbOfElemsRet+1,1);
  ret->setConnectivity(connRetArr,connIndexRetArr,false);
  ret->_types=types;
  ret->copyTinyInfoFrom(this);
  return ret.retn();
}

/*!
 * brief returns the volumes of the cells underlying the field \a field
 *
 * For 2D geometries, the returned field contains the areas.
 * For 3D geometries, the returned field contains the volumes.
 *
 * param field field on which cells the volumes are required
 * return field containing the volumes, area or length depending the meshdimension.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::getMeasureField(bool isAbs) const
{
  std::string name="MeasureOfMesh_";
  name+=getName();
  int nbelem=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> field=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  field->setName(name.c_str());
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> array=DataArrayDouble::New();
  array->alloc(nbelem,1);
  double *area_vol=array->getPointer();
  field->setArray(array) ; array=0;
  field->setMesh(const_cast<MEDCouplingUMesh *>(this));
  field->synchronizeTimeWithMesh();
  if(getMeshDimension()!=-1)
    {
      int ipt;
      INTERP_KERNEL::NormalizedCellType type;
      int dim_space=getSpaceDimension();
      const double *coords=getCoords()->getConstPointer();
      const int *connec=getNodalConnectivity()->getConstPointer();
      const int *connec_index=getNodalConnectivityIndex()->getConstPointer();
      for(int iel=0;iel<nbelem;iel++)
        {
          ipt=connec_index[iel];
          type=(INTERP_KERNEL::NormalizedCellType)connec[ipt];
          area_vol[iel]=INTERP_KERNEL::computeVolSurfOfCell2<int,INTERP_KERNEL::ALL_C_MODE>(type,connec+ipt+1,connec_index[iel+1]-ipt-1,coords,dim_space);
        }
      if(isAbs)
        std::transform(area_vol,area_vol+nbelem,area_vol,std::ptr_fun<double,double>(fabs));
    }
  else
    {
      area_vol[0]=std::numeric_limits<double>::max();
    }
  return field.retn();
}

/*!
 * This method is equivalent to MEDCouplingUMesh::getMeasureField except that only part defined by [begin,end) is returned !
 * This method avoids to build explicitely part of this to perform the work.
 */
DataArrayDouble *MEDCouplingUMesh::getPartMeasureField(bool isAbs, const int *begin, const int *end) const
{
  std::string name="PartMeasureOfMesh_";
  name+=getName();
  int nbelem=(int)std::distance(begin,end);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> array=DataArrayDouble::New();
  array->setName(name.c_str());
  array->alloc(nbelem,1);
  double *area_vol=array->getPointer();
  if(getMeshDimension()!=-1)
    {
      int ipt;
      INTERP_KERNEL::NormalizedCellType type;
      int dim_space=getSpaceDimension();
      const double *coords=getCoords()->getConstPointer();
      const int *connec=getNodalConnectivity()->getConstPointer();
      const int *connec_index=getNodalConnectivityIndex()->getConstPointer();
      for(const int *iel=begin;iel!=end;iel++)
        {
          ipt=connec_index[*iel];
          type=(INTERP_KERNEL::NormalizedCellType)connec[ipt];
          *area_vol++=INTERP_KERNEL::computeVolSurfOfCell2<int,INTERP_KERNEL::ALL_C_MODE>(type,connec+ipt+1,connec_index[*iel+1]-ipt-1,coords,dim_space);
        }
      if(isAbs)
        std::transform(array->getPointer(),area_vol,array->getPointer(),std::ptr_fun<double,double>(fabs));
    }
  else
    {
      area_vol[0]=std::numeric_limits<double>::max();
    }
  return array.retn();
}

/*!
 * This methods returns a field on nodes and no time. This method is useful to check "P1*" conservative interpolators.
 * This field returns the getMeasureField of the dualMesh in P1 sens of 'this'.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::getMeasureFieldOnNode(bool isAbs) const
{
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> tmp=getMeasureField(isAbs);
  std::string name="MeasureOnNodeOfMesh_";
  name+=getName();
  int nbNodes=getNumberOfNodes();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_NODES);
  double cst=1./((double)getMeshDimension()+1.);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> array=DataArrayDouble::New();
  array->alloc(nbNodes,1);
  double *valsToFill=array->getPointer();
  std::fill(valsToFill,valsToFill+nbNodes,0.);
  const double *values=tmp->getArray()->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> da=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> daInd=DataArrayInt::New();
  getReverseNodalConnectivity(da,daInd);
  const int *daPtr=da->getConstPointer();
  const int *daIPtr=daInd->getConstPointer();
  for(int i=0;i<nbNodes;i++)
    for(const int *cell=daPtr+daIPtr[i];cell!=daPtr+daIPtr[i+1];cell++)
      valsToFill[i]+=cst*values[*cell];
  ret->setMesh(this);
  ret->setArray(array);
  return ret.retn();
}

/*!
 * This methods returns a vector field on cells that represents the orthogonal vector normalized of each 2D cell of this.
 * This method is only callable on mesh with meshdim == 2 and spacedim==2 or 3.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::buildOrthogonalField() const
{
  if((getMeshDimension()!=2) && (getMeshDimension()!=1 || getSpaceDimension()!=2))
    throw INTERP_KERNEL::Exception("Expected a umesh with ( meshDim == 2 spaceDim == 2 or 3 ) or ( meshDim == 1 spaceDim == 2 ) !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> array=DataArrayDouble::New();
  int nbOfCells=getNumberOfCells();
  int nbComp=getMeshDimension()+1;
  array->alloc(nbOfCells,nbComp);
  double *vals=array->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  const double *coords=_coords->getConstPointer();
  if(getMeshDimension()==2)
    {
      if(getSpaceDimension()==3)
        {
          MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> loc=getBarycenterAndOwner();
          const double *locPtr=loc->getConstPointer();
          for(int i=0;i<nbOfCells;i++,vals+=3)
            {
              int offset=connI[i];
              INTERP_KERNEL::crossprod<3>(locPtr+3*i,coords+3*conn[offset+1],coords+3*conn[offset+2],vals);
              double n=INTERP_KERNEL::norm<3>(vals);
              std::transform(vals,vals+3,vals,std::bind2nd(std::multiplies<double>(),1./n));
            }
        }
      else
        {
          for(int i=0;i<nbOfCells;i++)
            { vals[3*i]=0.; vals[3*i+1]=0.; vals[3*i+2]=1.; }
        }
    }
  else//meshdimension==1
    {
      double tmp[2];
      for(int i=0;i<nbOfCells;i++)
        {
          int offset=connI[i];
          std::transform(coords+2*conn[offset+2],coords+2*conn[offset+2]+2,coords+2*conn[offset+1],tmp,std::minus<double>());
          double n=INTERP_KERNEL::norm<2>(tmp);
          std::transform(tmp,tmp+2,tmp,std::bind2nd(std::multiplies<double>(),1./n));
          *vals++=-tmp[1];
          *vals++=tmp[0];
        }
    }
  ret->setArray(array);
  ret->setMesh(this);
  ret->synchronizeTimeWithSupport();
  return ret.retn();
}

/*!
 * This method is equivalent to MEDCouplingUMesh::buildOrthogonalField except that only part defined by [begin,end) is returned !
 * This method avoids to build explicitely part of this to perform the work.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::buildPartOrthogonalField(const int *begin, const int *end) const
{
  if((getMeshDimension()!=2) && (getMeshDimension()!=1 || getSpaceDimension()!=2))
    throw INTERP_KERNEL::Exception("Expected a umesh with ( meshDim == 2 spaceDim == 2 or 3 ) or ( meshDim == 1 spaceDim == 2 ) !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> array=DataArrayDouble::New();
  std::size_t nbelems=std::distance(begin,end);
  int nbComp=getMeshDimension()+1;
  array->alloc((int)nbelems,nbComp);
  double *vals=array->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  const double *coords=_coords->getConstPointer();
  if(getMeshDimension()==2)
    {
      if(getSpaceDimension()==3)
        {
          MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> loc=getPartBarycenterAndOwner(begin,end);
          const double *locPtr=loc->getConstPointer();
          for(const int *i=begin;i!=end;i++,vals+=3,locPtr+=3)
            {
              int offset=connI[*i];
              INTERP_KERNEL::crossprod<3>(locPtr,coords+3*conn[offset+1],coords+3*conn[offset+2],vals);
              double n=INTERP_KERNEL::norm<3>(vals);
              std::transform(vals,vals+3,vals,std::bind2nd(std::multiplies<double>(),1./n));
            }
        }
      else
        {
          for(std::size_t i=0;i<nbelems;i++)
            { vals[3*i]=0.; vals[3*i+1]=0.; vals[3*i+2]=1.; }
        }
    }
  else//meshdimension==1
    {
      double tmp[2];
      for(const int *i=begin;i!=end;i++)
        {
          int offset=connI[*i];
          std::transform(coords+2*conn[offset+2],coords+2*conn[offset+2]+2,coords+2*conn[offset+1],tmp,std::minus<double>());
          double n=INTERP_KERNEL::norm<2>(tmp);
          std::transform(tmp,tmp+2,tmp,std::bind2nd(std::multiplies<double>(),1./n));
          *vals++=-tmp[1];
          *vals++=tmp[0];
        }
    }
  ret->setArray(array);
  ret->setMesh(this);
  ret->synchronizeTimeWithSupport();
  return ret.retn();
}

/*!
 * This methods returns a vector newly created field on cells that represents the direction vector of each 1D cell of this.
 * This method is only callable on mesh with meshdim == 1 containing only SEG2.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::buildDirectionVectorField() const
{
   if(getMeshDimension()!=1)
    throw INTERP_KERNEL::Exception("Expected a umesh with meshDim == 1 for buildDirectionVectorField !");
   if(_types.size()!=1 || *(_types.begin())!=INTERP_KERNEL::NORM_SEG2)
     throw INTERP_KERNEL::Exception("Expected a umesh with only NORM_SEG2 type of elements for buildDirectionVectorField !");
   MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
   MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> array=DataArrayDouble::New();
   int nbOfCells=getNumberOfCells();
   int spaceDim=getSpaceDimension();
   array->alloc(nbOfCells,spaceDim);
   double *pt=array->getPointer();
   const double *coo=getCoords()->getConstPointer();
   std::vector<int> conn;
   conn.reserve(2);
   for(int i=0;i<nbOfCells;i++)
     {
       conn.resize(0);
       getNodeIdsOfCell(i,conn);
       pt=std::transform(coo+conn[1]*spaceDim,coo+(conn[1]+1)*spaceDim,coo+conn[0]*spaceDim,pt,std::minus<double>());
     }
   ret->setArray(array);
   ret->setMesh(this);
   ret->synchronizeTimeWithSupport();
   return ret.retn();   
}

/*!
 * This method expects that 'this' is fully defined and has a spaceDim==3 and a meshDim==3. If it is not the case an exception will be thrown.
 * This method returns 2 objects : 
 * - a newly created mesh instance containing the result of the slice lying on different coords than 'this' and with a meshdim == 2
 * - a newly created dataarray having number of tuples equal to the number of cells in returned mesh that tells for each 2D cell in returned
 *   mesh the 3D cell id is 'this' it comes from.
 * This method works only for linear meshes (non quadratic).
 * If plane crosses within 'eps' a face in 'this' shared by more than 1 cell, 2 output faces will be generated. The 2 faces having the same geometry than intersecting
 * face. Only 'cellIds' parameter can distinguish the 2.
 * @param origin is the origin of the plane. It should be an array of length 3.
 * @param vec is the direction vector of the plane. It should be an array of length 3. Norm of 'vec' should be > 1e-6.
 * @param eps is the precision. It is used by called method MEDCouplingUMesh::getCellIdsCrossingPlane for the first 3D cell selection (in absolute). 'eps' is
 * also used to state if new points should be created or already existing points are reused. 'eps' is also used to tells if plane overlaps a face, edge or nodes (in absolute).
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildSlice3D(const double *origin, const double *vec, double eps, DataArrayInt *&cellIds) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3D works on umeshes with meshdim equal to 3 and spaceDim equal to 3 too!");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> candidates=getCellIdsCrossingPlane(origin,vec,eps);
  if(candidates->empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3D : No 3D cells in this intercepts the specified plane considering bounding boxes !");
  std::vector<int> nodes;
  DataArrayInt *cellIds1D=0;
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> subMesh=static_cast<MEDCouplingUMesh*>(buildPartOfMySelf(candidates->begin(),candidates->end(),false));
  subMesh->findNodesOnPlane(origin,vec,eps,nodes);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc1=DataArrayInt::New(),desc2=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descIndx1=DataArrayInt::New(),descIndx2=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc1=DataArrayInt::New(),revDesc2=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx1=DataArrayInt::New(),revDescIndx2=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mDesc2=subMesh->buildDescendingConnectivity(desc2,descIndx2,revDesc2,revDescIndx2);//meshDim==2 spaceDim==3
  revDesc2=0; revDescIndx2=0;
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mDesc1=mDesc2->buildDescendingConnectivity(desc1,descIndx1,revDesc1,revDescIndx1);//meshDim==1 spaceDim==3
  revDesc1=0; revDescIndx1=0;
  mDesc1->fillCellIdsToKeepFromNodeIds(&nodes[0],&nodes[0]+nodes.size(),true,cellIds1D);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIds1DTmp(cellIds1D);
  //
  std::vector<int> cut3DCurve(mDesc1->getNumberOfCells(),-2);
  for(const int *it=cellIds1D->begin();it!=cellIds1D->end();it++)
    cut3DCurve[*it]=-1;
  mDesc1->split3DCurveWithPlane(origin,vec,eps,cut3DCurve);
  std::vector< std::pair<int,int> > cut3DSurf(mDesc2->getNumberOfCells());
  AssemblyForSplitFrom3DCurve(cut3DCurve,nodes,mDesc2->getNodalConnectivity()->getConstPointer(),mDesc2->getNodalConnectivityIndex()->getConstPointer(),
                              mDesc1->getNodalConnectivity()->getConstPointer(),mDesc1->getNodalConnectivityIndex()->getConstPointer(),
                              desc1->getConstPointer(),descIndx1->getConstPointer(),cut3DSurf);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(DataArrayInt::New()),connI(DataArrayInt::New()),cellIds2(DataArrayInt::New());
  connI->pushBackSilent(0); conn->alloc(0,1); cellIds2->alloc(0,1);
  subMesh->assemblyForSplitFrom3DSurf(cut3DSurf,desc2->getConstPointer(),descIndx2->getConstPointer(),conn,connI,cellIds2);
  if(cellIds2->empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3D : No 3D cells in this intercepts the specified plane !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New("Slice3D",2);
  ret->setCoords(mDesc1->getCoords());
  ret->setConnectivity(conn,connI,true);
  cellIds=candidates->selectByTupleId(cellIds2->begin(),cellIds2->end());
  return ret.retn();
}

/*!
 * This method expects that 'this' is fully defined and has a spaceDim==3 and a meshDim==2. If it is not the case an exception will be thrown.
 * This method returns 2 objects : 
 * - a newly created mesh instance containing the result of the slice lying on different coords than 'this' and with a meshdim == 1
 * - a newly created dataarray having number of tuples equal to the number of cells in returned mesh that tells for each 2D cell in returned
 *   mesh the 3DSurf cell id is 'this' it comes from.
 * This method works only for linear meshes (non quadratic).
 * If plane crosses within 'eps' a face in 'this' shared by more than 1 cell, 2 output faces will be generated. The 2 faces having the same geometry than intersecting
 * face. Only 'cellIds' parameter can distinguish the 2.
 * @param origin is the origin of the plane. It should be an array of length 3.
 * @param vec is the direction vector of the plane. It should be an array of length 3. Norm of 'vec' should be > 1e-6.
 * @param eps is the precision. It is used by called method MEDCouplingUMesh::getCellIdsCrossingPlane for the first 3DSurf cell selection (in absolute). 'eps' is
 * also used to state if new points should be created or already existing points are reused. 'eps' is also used to tells if plane overlaps a face, edge or nodes (in absolute).
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildSlice3DSurf(const double *origin, const double *vec, double eps, DataArrayInt *&cellIds) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=2 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3DSurf works on umeshes with meshdim equal to 2 and spaceDim equal to 3 !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> candidates=getCellIdsCrossingPlane(origin,vec,eps);
  if(candidates->empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3DSurf : No 3D surf cells in this intercepts the specified plane considering bounding boxes !");
  std::vector<int> nodes;
  DataArrayInt *cellIds1D=0;
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> subMesh=static_cast<MEDCouplingUMesh*>(buildPartOfMySelf(candidates->begin(),candidates->end(),false));
  subMesh->findNodesOnPlane(origin,vec,eps,nodes);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descIndx1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mDesc1=subMesh->buildDescendingConnectivity(desc1,descIndx1,revDesc1,revDescIndx1);//meshDim==1 spaceDim==3
  mDesc1->fillCellIdsToKeepFromNodeIds(&nodes[0],&nodes[0]+nodes.size(),true,cellIds1D);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIds1DTmp(cellIds1D);
  //
  std::vector<int> cut3DCurve(mDesc1->getNumberOfCells(),-2);
  for(const int *it=cellIds1D->begin();it!=cellIds1D->end();it++)
    cut3DCurve[*it]=-1;
  mDesc1->split3DCurveWithPlane(origin,vec,eps,cut3DCurve);
  int ncellsSub=subMesh->getNumberOfCells();
  std::vector< std::pair<int,int> > cut3DSurf(ncellsSub);
  AssemblyForSplitFrom3DCurve(cut3DCurve,nodes,subMesh->getNodalConnectivity()->getConstPointer(),subMesh->getNodalConnectivityIndex()->getConstPointer(),
                              mDesc1->getNodalConnectivity()->getConstPointer(),mDesc1->getNodalConnectivityIndex()->getConstPointer(),
                              desc1->getConstPointer(),descIndx1->getConstPointer(),cut3DSurf);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(DataArrayInt::New()),connI(DataArrayInt::New()),cellIds2(DataArrayInt::New()); connI->pushBackSilent(0);
  conn->alloc(0,1);
  const int *nodal=subMesh->getNodalConnectivity()->getConstPointer();
  const int *nodalI=subMesh->getNodalConnectivityIndex()->getConstPointer();
  for(int i=0;i<ncellsSub;i++)
    {
      if(cut3DSurf[i].first!=-1 && cut3DSurf[i].second!=-1)
        {
          if(cut3DSurf[i].first!=-2)
            {
              conn->pushBackSilent((int)INTERP_KERNEL::NORM_SEG2); conn->pushBackSilent(cut3DSurf[i].first); conn->pushBackSilent(cut3DSurf[i].second);
              connI->pushBackSilent(conn->getNumberOfTuples());
              cellIds2->pushBackSilent(i);
            }
          else
            {
              int cellId3DSurf=cut3DSurf[i].second;
              int offset=nodalI[cellId3DSurf]+1;
              int nbOfEdges=nodalI[cellId3DSurf+1]-offset;
              for(int j=0;j<nbOfEdges;j++)
                {
                  conn->pushBackSilent((int)INTERP_KERNEL::NORM_SEG2); conn->pushBackSilent(nodal[offset+j]); conn->pushBackSilent(nodal[offset+(j+1)%nbOfEdges]);
                  connI->pushBackSilent(conn->getNumberOfTuples());
                  cellIds2->pushBackSilent(cellId3DSurf);
                }
            }
        }
    }
  if(cellIds2->empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3DSurf : No 3DSurf cells in this intercepts the specified plane !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New("Slice3DSurf",1);
  ret->setCoords(mDesc1->getCoords());
  ret->setConnectivity(conn,connI,true);
  cellIds=candidates->selectByTupleId(cellIds2->begin(),cellIds2->end());
  return ret.retn();
}

/*!
 * This method expects that 'this' is fully defined and has a spaceDim==3. If it is not the case an exception will be thrown.
 * This method returns a newly created dataarray containing cellsids in 'this' that potentially crosses the plane specified by 'origin' and 'vec'.
 * @param origin is the origin of the plane. It should be an array of length 3.
 * @param vec is the direction vector of the plane. It should be an array of length 3. Norm of 'vec' should be > 1e-6.
 */
DataArrayInt *MEDCouplingUMesh::getCellIdsCrossingPlane(const double *origin, const double *vec, double eps) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSlice3D works on umeshes with spaceDim equal to 3 !");
  double normm=sqrt(vec[0]*vec[0]+vec[1]*vec[1]+vec[2]*vec[2]);
  if(normm<1e-6)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getCellIdsCrossingPlane : parameter 'vec' should have a norm2 greater than 1e-6 !");
  double vec2[3];
  vec2[0]=vec[1]; vec2[1]=-vec[0]; vec2[2]=0.;//vec2 is the result of cross product of vec with (0,0,1)
  double angle=acos(vec[2]/normm);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIds;
  double bbox[6];
  if(angle>eps)
    {
      MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coo=_coords->deepCpy();
      MEDCouplingPointSet::Rotate3DAlg(origin,vec2,angle,coo->getNumberOfTuples(),coo->getPointer());
      MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mw=clone(false);//false -> shallow copy
      mw->setCoords(coo);
      mw->getBoundingBox(bbox);
      bbox[4]=origin[2]-eps; bbox[5]=origin[2]+eps;
      cellIds=mw->getCellsInBoundingBox(bbox,eps);
    }
  else
    {
      getBoundingBox(bbox);
      bbox[4]=origin[2]-eps; bbox[5]=origin[2]+eps;
      cellIds=getCellsInBoundingBox(bbox,eps);
    }
  return cellIds.retn();
}

/*!
 * This method checks that 'this' is a contiguous mesh. The user is expected to call this method on a mesh with meshdim==1.
 * If not an exception will thrown. If this is an empty mesh with no cell an exception will be thrown too.
 * No consideration of coordinate is done by this method.
 * A 1D mesh is said contiguous if : a cell i with nodal connectivity (k,p) the cell i+1 the nodal connectivity should be (p,m)
 * If not false is returned. In case that false is returned a call to ParaMEDMEM::MEDCouplingUMesh::mergeNodes could be usefull.
 */
bool MEDCouplingUMesh::isContiguous1D() const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::isContiguous1D : this method has a sense only for 1D mesh !");
  int nbCells=getNumberOfCells();
  if(nbCells<1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::isContiguous1D : this method has a sense for non empty mesh !");
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  int ref=conn[connI[0]+2];
  for(int i=1;i<nbCells;i++)
    {
      if(conn[connI[i]+1]!=ref)
        return false;
      ref=conn[connI[i]+2];
    }
  return true;
}

/*!
 * This method is only callable on mesh with meshdim == 1 containing only SEG2 and spaceDim==3.
 * This method projects this on the 3D line defined by (pt,v). This methods first checks that all SEG2 are along v vector.
 * @param pt reference point of the line
 * @param v normalized director vector of the line
 * @param eps max precision before throwing an exception
 * @param res output of size this->getNumberOfCells
 */
void MEDCouplingUMesh::project1D(const double *pt, const double *v, double eps, double *res) const
{
  if(getMeshDimension()!=1)
    throw INTERP_KERNEL::Exception("Expected a umesh with meshDim == 1 for project1D !");
   if(_types.size()!=1 || *(_types.begin())!=INTERP_KERNEL::NORM_SEG2)
     throw INTERP_KERNEL::Exception("Expected a umesh with only NORM_SEG2 type of elements for project1D !");
   if(getSpaceDimension()!=3)
     throw INTERP_KERNEL::Exception("Expected a umesh with spaceDim==3 for project1D !");
   MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> f=buildDirectionVectorField();
   const double *fPtr=f->getArray()->getConstPointer();
   double tmp[3];
   for(int i=0;i<getNumberOfCells();i++)
     {
       const double *tmp1=fPtr+3*i;
       tmp[0]=tmp1[1]*v[2]-tmp1[2]*v[1];
       tmp[1]=tmp1[2]*v[0]-tmp1[0]*v[2];
       tmp[2]=tmp1[0]*v[1]-tmp1[1]*v[0];
       double n1=INTERP_KERNEL::norm<3>(tmp);
       n1/=INTERP_KERNEL::norm<3>(tmp1);
       if(n1>eps)
         throw INTERP_KERNEL::Exception("UMesh::Projection 1D failed !");
     }
   const double *coo=getCoords()->getConstPointer();
   for(int i=0;i<getNumberOfNodes();i++)
     {
       std::transform(coo+i*3,coo+i*3+3,pt,tmp,std::minus<double>());
       std::transform(tmp,tmp+3,v,tmp,std::multiplies<double>());
       res[i]=std::accumulate(tmp,tmp+3,0.);
     }
}

/*!
 * This method computes the distance from a point \a pt to \a this and the first \a cellId and \a nodeId in \a this corresponding to the returned distance. 
 * \a this is expected to be a mesh so that its space dimension is equal to its
 * mesh dimension + 1. Furthermore only mesh dimension 1 and 2 are supported for the moment.
 * Distance from \a ptBg to \a ptEnd is expected to be equal to the space dimension. \a this is also expected to be fully defined (connectivity and coordinates).
 * 
 * This method firstly find the closer node in \a this to the requested point whose coordinates are defined by [ \a ptBg, \a ptEnd ). Then for this node found 
 * the cells sharing this node (if any) are considered to find if the distance to these cell are smaller than the result found previously. If no cells are linked
 * to the node that minimizes distance with the input point then -1 is returned in cellId.
 *
 * So this method is more accurate (so, more costly) than simply searching for the closest point in \a this.
 * If only this information is enough for you simply call \c getCoords()->distanceToTuple on \a this.
 *
 * \param [in] ptBg the start pointer (included) of the coordinates of the point
 * \param [in] ptEnd the end pointer (not included) of the coordinates of the point
 * \param [out] cellId that corresponds to minimal distance. If the closer node is not linked to any cell in \a this -1 is returned.
 * \return the positive value of the distance.
 * \throw if distance from \a ptBg to \a ptEnd is not equal to the space dimension. An exception is also thrown if mesh dimension of \a this is not equal to space
 * dimension - 1.
 * \sa DataArrayDouble::distanceToTuple
 */
double MEDCouplingUMesh::distanceToPoint(const double *ptBg, const double *ptEnd, int& cellId, int& nodeId) const throw(INTERP_KERNEL::Exception)
{
  int meshDim=getMeshDimension(),spaceDim=getSpaceDimension();
  if(meshDim!=spaceDim-1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::distanceToPoint works only for spaceDim=meshDim+1 !");
  if(meshDim!=2 && meshDim!=1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::distanceToPoint : only mesh dimension 2 and 1 are implemented !");
  checkFullyDefined();
  if((int)std::distance(ptBg,ptEnd)!=spaceDim)
    { std::ostringstream oss; oss << "MEDCouplingUMesh::distanceToPoint : input point has to have dimension equal to the space dimension of this (" << spaceDim << ") !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
  nodeId=-1;
  double ret0=_coords->distanceToTuple(ptBg,ptEnd,nodeId);
  if(nodeId==-1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::distanceToPoint : something wrong with nodes in this !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIds=getCellIdsLyingOnNodes(&nodeId,&nodeId+1,false);
  switch(meshDim)
    {
    case 2:
      {
        distanceToPoint3DSurfAlg(ptBg,cellIds,ret0,cellId);
        return ret0;
      }
    case 1:
      {
        distanceToPoint2DCurveAlg(ptBg,cellIds,ret0,cellId);
        return ret0;
      }
    default:
      throw INTERP_KERNEL::Exception("MEDCouplingUMesh::distanceToPoint : only mesh dimension 2 and 1 are implemented !");
    }
  
  return ret0;
}


/*!
 * \param [in] pt the start pointer (included) of the coordinates of the point
 * \param [in] cellIds
 * \param [in,out] ret0 the min distance between \a this and the external input point
 * \param [out] cellId that corresponds to minimal distance. If the closer node is not linked to any cell in \a this -1 is returned.
 * \sa MEDCouplingUMesh::distanceToPoint
 */
void MEDCouplingUMesh::distanceToPoint3DSurfAlg(const double *pt, const DataArrayInt *cellIds, double& ret0, int& cellId) const throw(INTERP_KERNEL::Exception)
{
  const double *coords=_coords->getConstPointer();
  cellId=-1; 
  if(cellIds->empty())
    return;
  const int *ptr=_nodal_connec->getConstPointer();
  const int *ptrI=_nodal_connec_index->getConstPointer();
  for(const int *zeCell=cellIds->begin();zeCell!=cellIds->end();zeCell++)
    {
      switch((INTERP_KERNEL::NormalizedCellType)ptr[ptrI[*zeCell]])
        {
        case INTERP_KERNEL::NORM_TRI3:
          {
            double tmp=INTERP_KERNEL::DistanceFromPtToTriInSpaceDim3(pt,coords+3*ptr[ptrI[*zeCell]+1],coords+3*ptr[ptrI[*zeCell]+2],coords+3*ptr[ptrI[*zeCell]+3]);
            if(tmp<ret0)
              { ret0=tmp; cellId=*zeCell; }
            break;
          }
        case INTERP_KERNEL::NORM_QUAD4:
        case INTERP_KERNEL::NORM_POLYGON:
          {
            double tmp=INTERP_KERNEL::DistanceFromPtToPolygonInSpaceDim3(pt,ptr+ptrI[*zeCell]+1,ptr+ptrI[*zeCell+1],coords);
            if(tmp<ret0)
              { ret0=tmp; cellId=*zeCell; }
            break;
          }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::distanceToPoint3DSurfAlg : not managed cell type ! Supporting TRI3, QUAD4 and POLYGON !");
        }
    }
}

/*!
 * \param [in] pt the start pointer (included) of the coordinates of the point
 * \param [in] cellIds
 * \param [in,out] ret0 the min distance between \a this and the external input point
 * \param [out] cellId that corresponds to minimal distance. If the closer node is not linked to any cell in \a this -1 is returned.
 * \sa MEDCouplingUMesh::distanceToPoint
 */
void MEDCouplingUMesh::distanceToPoint2DCurveAlg(const double *pt, const DataArrayInt *cellIds, double& ret0, int& cellId) const throw(INTERP_KERNEL::Exception)
{
  const double *coords=_coords->getConstPointer();
  if(cellIds->empty())
    { cellId=-1; return; }
  const int *ptr=_nodal_connec->getConstPointer();
  const int *ptrI=_nodal_connec_index->getConstPointer();
  for(const int *zeCell=cellIds->begin();zeCell!=cellIds->end();zeCell++)
    {
       switch((INTERP_KERNEL::NormalizedCellType)ptr[ptrI[*zeCell]])
        {
        case INTERP_KERNEL::NORM_SEG2:
          {
            double tmp=INTERP_KERNEL::SquareDistanceFromPtToSegInSpaceDim2(pt,coords+2*ptr[ptrI[*zeCell]+1],coords+2*ptr[ptrI[*zeCell]+2]);
            if(tmp!=std::numeric_limits<double>::max()) tmp=sqrt(tmp);
            if(tmp<ret0)
              { ret0=tmp; cellId=*zeCell; }
            break;
          }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::distanceToPoint2DCurveAlg : not managed cell type ! Supporting SEG2 !");
        }
    }
}

/*!
 * Returns a cell if any that contains the point located on 'pos' with precison eps.
 * If 'pos' is outside 'this' -1 is returned. If several cells contain this point the cell with the smallest id is returned.
 * \b Warning this method is good if the caller intends to evaluate only one point. But if more than one point is requested on 'this'
 * it is better to use MEDCouplingUMesh::getCellsContainingPoints method because in this case, the acceleration structure will be computed only once.
 */
int MEDCouplingUMesh::getCellContainingPoint(const double *pos, double eps) const
{
  std::vector<int> elts;
  getCellsContainingPoint(pos,eps,elts);
  if(elts.empty())
    return -1;
  return elts.front();
}

/*!
 * Returns all cellIds in 'elts' of point 'pos' with eps accuracy.
 * \b Warning this method is good if the caller intends to evaluate only one point. But if more than one point is requested on 'this'
 * it is better to use MEDCouplingUMesh::getCellsContainingPoints method because in this case, the acceleration structure will be computed only once.
 */
void MEDCouplingUMesh::getCellsContainingPoint(const double *pos, double eps, std::vector<int>& elts) const
{
  std::vector<int> eltsIndex;
  getCellsContainingPoints(pos,1,eps,elts,eltsIndex);
}

/// @cond INTERNAL

namespace ParaMEDMEM
{
  template<const int SPACEDIMM>
  class DummyClsMCUG
  {
  public:
    static const int MY_SPACEDIM=SPACEDIMM;
    static const int MY_MESHDIM=8;
    typedef int MyConnType;
    static const INTERP_KERNEL::NumberingPolicy My_numPol=INTERP_KERNEL::ALL_C_MODE;
    // begin
    // useless, but for windows compilation ...
    const double* getCoordinatesPtr() const { return 0; }
    const int* getConnectivityPtr() const { return 0; }
    const int* getConnectivityIndexPtr() const { return 0; }
    INTERP_KERNEL::NormalizedCellType getTypeOfElement(int) const { return (INTERP_KERNEL::NormalizedCellType)0; }
    // end
  };

  INTERP_KERNEL::Edge *MEDCouplingUMeshBuildQPFromEdge(INTERP_KERNEL::NormalizedCellType typ, std::map<int, std::pair<INTERP_KERNEL::Node *,bool> >& mapp2, const int *bg)
  {
    INTERP_KERNEL::Edge *ret=0;
    switch(typ)
      {
      case INTERP_KERNEL::NORM_SEG2:
        {
          ret=new INTERP_KERNEL::EdgeLin(mapp2[bg[0]].first,mapp2[bg[1]].first);
          break;
        }
      case INTERP_KERNEL::NORM_SEG3:
        {
          INTERP_KERNEL::EdgeLin *e1=new INTERP_KERNEL::EdgeLin(mapp2[bg[0]].first,mapp2[bg[2]].first);
          INTERP_KERNEL::EdgeLin *e2=new INTERP_KERNEL::EdgeLin(mapp2[bg[2]].first,mapp2[bg[1]].first);
          INTERP_KERNEL::SegSegIntersector inters(*e1,*e2);
          bool colinearity=inters.areColinears();
          delete e1; delete e2;
          if(colinearity)
            ret=new INTERP_KERNEL::EdgeLin(mapp2[bg[0]].first,mapp2[bg[1]].first);
          else
            ret=new INTERP_KERNEL::EdgeArcCircle(mapp2[bg[0]].first,mapp2[bg[2]].first,mapp2[bg[1]].first);
          mapp2[bg[2]].second=false;
          break;
        }
      default:
        throw INTERP_KERNEL::Exception("MEDCouplingUMeshBuildQPFromEdge : Expecting a mesh with spaceDim==2 and meshDim==1 !");
      }
    return ret;
  }

  /*!
   * This method creates a sub mesh in Geometric2D DS. The sub mesh is composed be the sub set of cells in 'candidates' and the global mesh 'mDesc'.
   * The input meth 'mDesc' must be so that mDim==1 et spaceDim==3.
   * 'mapp' contains a mapping between local numbering in submesh and the global node numbering in 'mDesc'.
   */
  INTERP_KERNEL::QuadraticPolygon *MEDCouplingUMeshBuildQPFromMesh(const MEDCouplingUMesh *mDesc, const std::vector<int>& candidates, std::map<INTERP_KERNEL::Node *,int>& mapp) throw(INTERP_KERNEL::Exception)
  {
    mapp.clear();
    std::map<int, std::pair<INTERP_KERNEL::Node *,bool> > mapp2;//bool is for a flag specifying if node is boundary (true) or only a middle for SEG3.
    const double *coo=mDesc->getCoords()->getConstPointer();
    const int *c=mDesc->getNodalConnectivity()->getConstPointer();
    const int *cI=mDesc->getNodalConnectivityIndex()->getConstPointer();
    std::set<int> s;
    for(std::vector<int>::const_iterator it=candidates.begin();it!=candidates.end();it++)
      s.insert(c+cI[*it]+1,c+cI[(*it)+1]);
    for(std::set<int>::const_iterator it2=s.begin();it2!=s.end();it2++)
      {
        INTERP_KERNEL::Node *n=new INTERP_KERNEL::Node(coo[2*(*it2)],coo[2*(*it2)+1]);
        mapp2[*it2]=std::pair<INTERP_KERNEL::Node *,bool>(n,true);
      }
    INTERP_KERNEL::QuadraticPolygon *ret=new INTERP_KERNEL::QuadraticPolygon;
    for(std::vector<int>::const_iterator it=candidates.begin();it!=candidates.end();it++)
      {
        INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)c[cI[*it]];
        ret->pushBack(MEDCouplingUMeshBuildQPFromEdge(typ,mapp2,c+cI[*it]+1));
      }
    for(std::map<int, std::pair<INTERP_KERNEL::Node *,bool> >::const_iterator it2=mapp2.begin();it2!=mapp2.end();it2++)
      {
        if((*it2).second.second)
          mapp[(*it2).second.first]=(*it2).first;
        ((*it2).second.first)->decrRef();
      }
    return ret;
  }

  INTERP_KERNEL::Node *MEDCouplingUMeshBuildQPNode(int nodeId, const double *coo1, int offset1, const double *coo2, int offset2, const std::vector<double>& addCoo)
  {
    if(nodeId>=offset2)
      {
        int locId=nodeId-offset2;
        return new INTERP_KERNEL::Node(addCoo[2*locId],addCoo[2*locId+1]);
      }
    if(nodeId>=offset1)
      {
        int locId=nodeId-offset1;
        return new INTERP_KERNEL::Node(coo2[2*locId],coo2[2*locId+1]);
      }
    return new INTERP_KERNEL::Node(coo1[2*nodeId],coo1[2*nodeId+1]);
  }

  void MEDCouplingUMeshBuildQPFromMesh3(const double *coo1, int offset1, const double *coo2, int offset2, const std::vector<double>& addCoo,
                                        const int *desc1Bg, const int *desc1End, const std::vector<std::vector<int> >& intesctEdges1,
                                        /*output*/std::map<INTERP_KERNEL::Node *,int>& mapp, std::map<int,INTERP_KERNEL::Node *>& mappRev)
  {
    for(const int *desc1=desc1Bg;desc1!=desc1End;desc1++)
      {
        int eltId1=abs(*desc1)-1;
        for(std::vector<int>::const_iterator it1=intesctEdges1[eltId1].begin();it1!=intesctEdges1[eltId1].end();it1++)
          {
            std::map<int,INTERP_KERNEL::Node *>::const_iterator it=mappRev.find(*it1);
            if(it==mappRev.end())
              {
                INTERP_KERNEL::Node *node=MEDCouplingUMeshBuildQPNode(*it1,coo1,offset1,coo2,offset2,addCoo);
                mapp[node]=*it1;
                mappRev[*it1]=node;
              }
          }
      }
  }
}

/// @endcond

template<int SPACEDIM>
void MEDCouplingUMesh::getCellsContainingPointsAlg(const double *coords, const double *pos, int nbOfPoints,
                                                   double eps, std::vector<int>& elts, std::vector<int>& eltsIndex) const
{
  std::vector<double> bbox;
  eltsIndex.resize(nbOfPoints+1);
  eltsIndex[0]=0;
  elts.clear();
  getBoundingBoxForBBTree(bbox);
  int nbOfCells=getNumberOfCells();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  double bb[2*SPACEDIM];
  BBTree<SPACEDIM,int> myTree(&bbox[0],0,0,nbOfCells,-eps);
  for(int i=0;i<nbOfPoints;i++)
    {
      eltsIndex[i+1]=eltsIndex[i];
      for(int j=0;j<SPACEDIM;j++)
        {
          bb[2*j]=pos[SPACEDIM*i+j];
          bb[2*j+1]=pos[SPACEDIM*i+j];
        }
      std::vector<int> candidates;
      myTree.getIntersectingElems(bb,candidates);
      for(std::vector<int>::const_iterator iter=candidates.begin();iter!=candidates.end();iter++)
        {
          int sz=connI[(*iter)+1]-connI[*iter]-1;
          if(INTERP_KERNEL::PointLocatorAlgos<DummyClsMCUG<SPACEDIM> >::isElementContainsPoint(pos+i*SPACEDIM,
                                                                                               (INTERP_KERNEL::NormalizedCellType)conn[connI[*iter]],
                                                                                               coords,conn+connI[*iter]+1,sz,eps))
            {
              eltsIndex[i+1]++;
              elts.push_back(*iter);
            }
        }
    }
}

/*!
 * This method is an extension of MEDCouplingUMesh::getCellContainingPoint and MEDCouplingUMesh::getCellsContainingPoint.
 * This method performs 'nbOfPoints' time the getCellsContainingPoint request. This method is recommended rather than the 2 others
 * in case of multi points searching.
 * This method returns 2 arrays 'elts' and 'eltsIndex'. 'eltsIndex' is of size 'nbOfPoints+1' and 'elts' is of size 'eltsIndex[nbOfPoints-1]'.
 * For point j in [0,nbOfPoints), (eltsIndex[j+1]-eltsIndex[j]) cells contain this point. These cells are : [elts.begin()+eltsIndex[j],elts.begin():eltsIndex[j+1]).
 * 
 * \param pos input parameter that points to an array of size 'getSpaceDim()*nbOfPoints' points stored in full interlace mode : X0,Y0,Z0,X1,Y1,Z1...
 */
void MEDCouplingUMesh::getCellsContainingPoints(const double *pos, int nbOfPoints, double eps,
                                                std::vector<int>& elts, std::vector<int>& eltsIndex) const
{
  int spaceDim=getSpaceDimension();
  int mDim=getMeshDimension();
  if(spaceDim==3)
    {
      if(mDim==3)
        {
          const double *coords=_coords->getConstPointer();
          getCellsContainingPointsAlg<3>(coords,pos,nbOfPoints,eps,elts,eltsIndex);
        }
      /*else if(mDim==2)
        {
          
        }*/
      else
        throw INTERP_KERNEL::Exception("For spaceDim==3 only meshDim==3 implemented for getelementscontainingpoints !");
    }
  else if(spaceDim==2)
    {
      if(mDim==2)
        {
          const double *coords=_coords->getConstPointer();
          getCellsContainingPointsAlg<2>(coords,pos,nbOfPoints,eps,elts,eltsIndex);
        }
      else
        throw INTERP_KERNEL::Exception("For spaceDim==2 only meshDim==2 implemented for getelementscontainingpoints !");
    }
  else if(spaceDim==1)
    {
      if(mDim==1)
        {
          const double *coords=_coords->getConstPointer();
          getCellsContainingPointsAlg<1>(coords,pos,nbOfPoints,eps,elts,eltsIndex);
        }
      else
        throw INTERP_KERNEL::Exception("For spaceDim==1 only meshDim==1 implemented for getelementscontainingpoints !");
    }
  else
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getCellsContainingPoints : not managed for mdim not in [1,2,3] !");
}

/*!
 * This method is only available for a mesh with meshDim==2 and spaceDim==2||spaceDim==3.
 * This method returns a vector 'cells' where all detected butterfly cells have been added to cells.
 * A 2D cell is considered to be butterfly if it exists at least one pair of distinct edges of it that intersect each other
 * anywhere excepted their extremities. An INTERP_KERNEL::NORM_NORI3 could \b not be butterfly.
 */
void MEDCouplingUMesh::checkButterflyCells(std::vector<int>& cells, double eps) const
{
  const char msg[]="Butterfly detection work only for 2D cells with spaceDim==2 or 3!";
  if(getMeshDimension()!=2)
    throw INTERP_KERNEL::Exception(msg);
  int spaceDim=getSpaceDimension();
  if(spaceDim!=2 && spaceDim!=3)
    throw INTERP_KERNEL::Exception(msg);
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::vector<double> cell2DinS2;
  for(int i=0;i<nbOfCells;i++)
    {
      int offset=connI[i];
      int nbOfNodesForCell=connI[i+1]-offset-1;
      if(nbOfNodesForCell<=3)
        continue;
      bool isQuad=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[offset]).isQuadratic();
      project2DCellOnXY(conn+offset+1,conn+connI[i+1],cell2DinS2);
      if(isButterfly2DCell(cell2DinS2,isQuad,eps))
        cells.push_back(i);
      cell2DinS2.clear();
    }
}

/*!
 * This method is typically requested to unbutterfly 2D linear cells in \b this.
 *
 * This method expects that space dimension is equal to 2 and mesh dimension is equal to 2 too. If it is not the case an INTERP_KERNEL::Exception will be thrown.
 * This method works only for linear 2D cells. If there is any of non linear cells (INTERP_KERNEL::NORM_QUAD8 for example) an INTERP_KERNEL::Exception will be thrown too.
 * 
 * For each 2D linear cell in \b this, this method builds the convex envelop (or the convex hull) of the current cell.
 * This convex envelop is computed using Jarvis march algorithm.
 * The coordinates and the number of cells of \b this remain unchanged on invocation of this method.
 * Only connectivity of some cells could be modified if those cells were not representing a convex envelop. If a cell already equals its convex envelop (regardless orientation)
 * its connectivity will remain unchanged. If the computation leads to a modification of nodal connectivity of a cell its geometric type will be modified to INTERP_KERNEL::NORM_POLYGON.
 *
 * @return a newly allocated array containing cellIds that have been modified if any. If no cells have been impacted by this method NULL is returned.
 */
DataArrayInt *MEDCouplingUMesh::convexEnvelop2D() throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=2 || getSpaceDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::convexEnvelop2D  works only for meshDim=2 and spaceDim=2 !");
  checkFullyDefined();
  const double *coords=getCoords()->getConstPointer();
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> nodalConnecIndexOut=DataArrayInt::New();
  nodalConnecIndexOut->alloc(nbOfCells+1,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> nodalConnecOut(DataArrayInt::New());
  int *workIndexOut=nodalConnecIndexOut->getPointer();
  *workIndexOut=0;
  const int *nodalConnecIn=_nodal_connec->getConstPointer();
  const int *nodalConnecIndexIn=_nodal_connec_index->getConstPointer();
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> isChanged(DataArrayInt::New());
  isChanged->alloc(0,1);
  for(int i=0;i<nbOfCells;i++,workIndexOut++)
    {
      int pos=nodalConnecOut->getNumberOfTuples();
      if(BuildConvexEnvelopOf2DCellJarvis(coords,nodalConnecIn+nodalConnecIndexIn[i],nodalConnecIn+nodalConnecIndexIn[i+1],nodalConnecOut))
        isChanged->pushBackSilent(i);
      types.insert((INTERP_KERNEL::NormalizedCellType)nodalConnecOut->getIJ(pos,0));
      workIndexOut[1]=nodalConnecOut->getNumberOfTuples();
    }
  if(isChanged->empty())
    return 0;
  setConnectivity(nodalConnecOut,nodalConnecIndexOut,false);
  _types=types;
  return isChanged.retn();
}

/*!
 * This method is \b NOT const because it can modify 'this'.
 * 'this' is expected to be an unstructured mesh with meshDim==2 and spaceDim==3. If not an exception will be thrown.
 * @param mesh1D is an unstructured mesh with MeshDim==1 and spaceDim==3. If not an exception will be thrown.
 * @param policy specifies the type of extrusion chosen. \b 0 for translation (most simple),
 * \b 1 for translation and rotation around point of 'mesh1D'.
 * @return an unstructured mesh with meshDim==3 and spaceDim==3. The returned mesh has the same coords than 'this'.  
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildExtrudedMesh(const MEDCouplingUMesh *mesh1D, int policy)
{
  checkFullyDefined();
  mesh1D->checkFullyDefined();
  if(!mesh1D->isContiguous1D())
    throw INTERP_KERNEL::Exception("buildExtrudedMesh : 1D mesh passed in parameter is not contiguous !");
  if(getSpaceDimension()!=mesh1D->getSpaceDimension())
    throw INTERP_KERNEL::Exception("Invalid call to buildExtrudedMesh this and mesh1D must have same space dimension !");
  if((getMeshDimension()!=2 || getSpaceDimension()!=3) && (getMeshDimension()!=1 || getSpaceDimension()!=2))
    throw INTERP_KERNEL::Exception("Invalid 'this' for buildExtrudedMesh method : must be (meshDim==2 and spaceDim==3) or (meshDim==1 and spaceDim==2) !");
  if(mesh1D->getMeshDimension()!=1)
    throw INTERP_KERNEL::Exception("Invalid 'mesh1D' for buildExtrudedMesh method : must be meshDim==1 !");
  bool isQuad=false;
  if(isPresenceOfQuadratic())
    {
      if(mesh1D->isFullyQuadratic())
        isQuad=true;
      else
        throw INTERP_KERNEL::Exception("Invalid 2D mesh and 1D mesh because 2D mesh has quadratic cells and 1D is not fully quadratic !");
    }
  zipCoords();
  int oldNbOfNodes=getNumberOfNodes();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> newCoords;
  switch(policy)
    {
    case 0:
      {
        newCoords=fillExtCoordsUsingTranslation(mesh1D,isQuad);
        break;
      }
    case 1:
      {
        newCoords=fillExtCoordsUsingTranslAndAutoRotation(mesh1D,isQuad);
        break;
      }
    default:
      throw INTERP_KERNEL::Exception("Not implemented extrusion policy : must be in (0) !");
    }
  setCoords(newCoords);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=buildExtrudedMeshFromThisLowLev(oldNbOfNodes,isQuad);
  updateTime();
  return ret.retn();
}

/*!
 * This method works on a 3D curve linear mesh that is to say (meshDim==1 and spaceDim==3).
 * If it is not the case an exception will be thrown.
 * This method is non const because the coordinate of 'this' can be appended with some new points issued from
 * intersection of plane defined by ('origin','vec').
 * This method has one in/out parameter : 'cut3DCurve'.
 * Param 'cut3DCurve' is expected to be of size 'this->getNumberOfCells()'. For each i in [0,'this->getNumberOfCells()')
 * if cut3DCurve[i]==-2, it means that for cell #i in 'this' nothing has been detected previously.
 * if cut3DCurve[i]==-1, it means that cell#i has been already detected to be fully part of plane defined by ('origin','vec').
 * This method will throw an exception if 'this' contains a non linear segment.
 */
void MEDCouplingUMesh::split3DCurveWithPlane(const double *origin, const double *vec, double eps, std::vector<int>& cut3DCurve) throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=1 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::split3DCurveWithPlane works on umeshes with meshdim equal to 1 and spaceDim equal to 3 !");
  int ncells=getNumberOfCells();
  int nnodes=getNumberOfNodes();
  double vec2[3],vec3[3],vec4[3];
  double normm=sqrt(vec[0]*vec[0]+vec[1]*vec[1]+vec[2]*vec[2]);
  if(normm<1e-6)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::split3DCurveWithPlane : parameter 'vec' should have a norm2 greater than 1e-6 !");
  vec2[0]=vec[0]/normm; vec2[1]=vec[1]/normm; vec2[2]=vec[2]/normm;
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coo=_coords->getConstPointer();
  std::vector<double> addCoo;
  for(int i=0;i<ncells;i++)
    {
      if(conn[connI[i]]==(int)INTERP_KERNEL::NORM_SEG2)
        {
          if(cut3DCurve[i]==-2)
            {
              int st=conn[connI[i]+1],endd=conn[connI[i]+2];
              vec3[0]=coo[3*endd]-coo[3*st]; vec3[1]=coo[3*endd+1]-coo[3*st+1]; vec3[2]=coo[3*endd+2]-coo[3*st+2];
              double normm2=sqrt(vec3[0]*vec3[0]+vec3[1]*vec3[1]+vec3[2]*vec3[2]);
              double colin=std::abs((vec3[0]*vec2[0]+vec3[1]*vec2[1]+vec3[2]*vec2[2])/normm2);
              if(colin>eps)//if colin<=eps -> current SEG2 is colinear to the input plane
                {
                  const double *st2=coo+3*st;
                  vec4[0]=st2[0]-origin[0]; vec4[1]=st2[1]-origin[1]; vec4[2]=st2[2]-origin[2];
                  double pos=-(vec4[0]*vec2[0]+vec4[1]*vec2[1]+vec4[2]*vec2[2])/((vec3[0]*vec2[0]+vec3[1]*vec2[1]+vec3[2]*vec2[2]));
                  if(pos>eps && pos<1-eps)
                    {
                      int nNode=((int)addCoo.size())/3;
                      vec4[0]=st2[0]+pos*vec3[0]; vec4[1]=st2[1]+pos*vec3[1]; vec4[2]=st2[2]+pos*vec3[2];
                      addCoo.insert(addCoo.end(),vec4,vec4+3);
                      cut3DCurve[i]=nnodes+nNode;
                    }
                }
            }
        }
      else
        throw INTERP_KERNEL::Exception("MEDCouplingUMesh::split3DCurveWithPlane : this method is only available for linear cell (NORM_SEG2) !");
    }
  if(!addCoo.empty())
    {
      int newNbOfNodes=nnodes+((int)addCoo.size())/3;
      MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coo2=DataArrayDouble::New();
      coo2->alloc(newNbOfNodes,3);
      double *tmp=coo2->getPointer();
      tmp=std::copy(_coords->begin(),_coords->end(),tmp);
      std::copy(addCoo.begin(),addCoo.end(),tmp);
      DataArrayDouble::SetArrayIn(coo2,_coords);
    }
}

/*!
 * This method incarnates the policy 0 for MEDCouplingUMesh::buildExtrudedMesh method.
 * @param mesh1D is the input 1D mesh used for translation computation.
 * @return newCoords new coords filled by this method. 
 */
DataArrayDouble *MEDCouplingUMesh::fillExtCoordsUsingTranslation(const MEDCouplingUMesh *mesh1D, bool isQuad) const
{
  int oldNbOfNodes=getNumberOfNodes();
  int nbOf1DCells=mesh1D->getNumberOfCells();
  int spaceDim=getSpaceDimension();
  DataArrayDouble *ret=DataArrayDouble::New();
  std::vector<bool> isQuads;
  int nbOfLevsInVec=isQuad?2*nbOf1DCells+1:nbOf1DCells+1;
  ret->alloc(oldNbOfNodes*nbOfLevsInVec,spaceDim);
  double *retPtr=ret->getPointer();
  const double *coords=getCoords()->getConstPointer();
  double *work=std::copy(coords,coords+spaceDim*oldNbOfNodes,retPtr);
  std::vector<int> v;
  std::vector<double> c;
  double vec[3];
  v.reserve(3);
  c.reserve(6);
  for(int i=0;i<nbOf1DCells;i++)
    {
      v.resize(0);
      mesh1D->getNodeIdsOfCell(i,v);
      c.resize(0);
      mesh1D->getCoordinatesOfNode(v[isQuad?2:1],c);
      mesh1D->getCoordinatesOfNode(v[0],c);
      std::transform(c.begin(),c.begin()+spaceDim,c.begin()+spaceDim,vec,std::minus<double>());
      for(int j=0;j<oldNbOfNodes;j++)
        work=std::transform(vec,vec+spaceDim,retPtr+spaceDim*(i*oldNbOfNodes+j),work,std::plus<double>());
      if(isQuad)
        {
          c.resize(0);
          mesh1D->getCoordinatesOfNode(v[1],c);
          mesh1D->getCoordinatesOfNode(v[0],c);
          std::transform(c.begin(),c.begin()+spaceDim,c.begin()+spaceDim,vec,std::minus<double>());
          for(int j=0;j<oldNbOfNodes;j++)
            work=std::transform(vec,vec+spaceDim,retPtr+spaceDim*(i*oldNbOfNodes+j),work,std::plus<double>());
        }
    }
  ret->copyStringInfoFrom(*getCoords());
  return ret;
}

/*!
 * This method incarnates the policy 1 for MEDCouplingUMesh::buildExtrudedMesh method.
 * @param mesh1D is the input 1D mesh used for translation and automatic rotation computation.
 * @return newCoords new coords filled by this method. 
 */
DataArrayDouble *MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation(const MEDCouplingUMesh *mesh1D, bool isQuad) const throw(INTERP_KERNEL::Exception)
{
  if(mesh1D->getSpaceDimension()==2)
    return fillExtCoordsUsingTranslAndAutoRotation2D(mesh1D,isQuad);
  if(mesh1D->getSpaceDimension()==3)
    return fillExtCoordsUsingTranslAndAutoRotation3D(mesh1D,isQuad);
  throw INTERP_KERNEL::Exception("Not implemented rotation and translation alg. for spacedim other than 2 and 3 !");
}

/*!
 * This method incarnates the policy 1 for MEDCouplingUMesh::buildExtrudedMesh method.
 * @param mesh1D is the input 1D mesh used for translation and automatic rotation computation.
 * @return newCoords new coords filled by this method. 
 */
DataArrayDouble *MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation2D(const MEDCouplingUMesh *mesh1D, bool isQuad) const throw(INTERP_KERNEL::Exception)
{
  if(isQuad)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation2D : not implemented for quadratic cells !");
  int oldNbOfNodes=getNumberOfNodes();
  int nbOf1DCells=mesh1D->getNumberOfCells();
  if(nbOf1DCells<2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation2D : impossible to detect any angle of rotation ! Change extrusion policy 1->0 !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> ret=DataArrayDouble::New();
  int nbOfLevsInVec=nbOf1DCells+1;
  ret->alloc(oldNbOfNodes*nbOfLevsInVec,2);
  double *retPtr=ret->getPointer();
  retPtr=std::copy(getCoords()->getConstPointer(),getCoords()->getConstPointer()+getCoords()->getNbOfElems(),retPtr);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> tmp=MEDCouplingUMesh::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> tmp2=getCoords()->deepCpy();
  tmp->setCoords(tmp2);
  const double *coo1D=mesh1D->getCoords()->getConstPointer();
  const int *conn1D=mesh1D->getNodalConnectivity()->getConstPointer();
  const int *connI1D=mesh1D->getNodalConnectivityIndex()->getConstPointer();
  for(int i=1;i<nbOfLevsInVec;i++)
    {
      const double *begin=coo1D+2*conn1D[connI1D[i-1]+1];
      const double *end=coo1D+2*conn1D[connI1D[i-1]+2];
      const double *third=i+1<nbOfLevsInVec?coo1D+2*conn1D[connI1D[i]+2]:coo1D+2*conn1D[connI1D[i-2]+1];
      const double vec[2]={end[0]-begin[0],end[1]-begin[1]};
      tmp->translate(vec);
      double tmp3[2],radius,alpha,alpha0;
      const double *p0=i+1<nbOfLevsInVec?begin:third;
      const double *p1=i+1<nbOfLevsInVec?end:begin;
      const double *p2=i+1<nbOfLevsInVec?third:end;
      INTERP_KERNEL::EdgeArcCircle::GetArcOfCirclePassingThru(p0,p1,p2,tmp3,radius,alpha,alpha0);
      double cosangle=i+1<nbOfLevsInVec?(p0[0]-tmp3[0])*(p1[0]-tmp3[0])+(p0[1]-tmp3[1])*(p1[1]-tmp3[1]):(p2[0]-tmp3[0])*(p1[0]-tmp3[0])+(p2[1]-tmp3[1])*(p1[1]-tmp3[1]);
      double angle=acos(cosangle/(radius*radius));
      tmp->rotate(end,0,angle);
      retPtr=std::copy(tmp2->getConstPointer(),tmp2->getConstPointer()+tmp2->getNbOfElems(),retPtr);
    }
  return ret.retn();
}

/*!
 * This method incarnates the policy 1 for MEDCouplingUMesh::buildExtrudedMesh method.
 * @param mesh1D is the input 1D mesh used for translation and automatic rotation computation.
 * @return newCoords new coords filled by this method. 
 */
DataArrayDouble *MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation3D(const MEDCouplingUMesh *mesh1D, bool isQuad) const throw(INTERP_KERNEL::Exception)
{
  if(isQuad)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation3D : not implemented for quadratic cells !");
  int oldNbOfNodes=getNumberOfNodes();
  int nbOf1DCells=mesh1D->getNumberOfCells();
  if(nbOf1DCells<2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::fillExtCoordsUsingTranslAndAutoRotation3D : impossible to detect any angle of rotation ! Change extrusion policy 1->0 !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> ret=DataArrayDouble::New();
  int nbOfLevsInVec=nbOf1DCells+1;
  ret->alloc(oldNbOfNodes*nbOfLevsInVec,3);
  double *retPtr=ret->getPointer();
  retPtr=std::copy(getCoords()->getConstPointer(),getCoords()->getConstPointer()+getCoords()->getNbOfElems(),retPtr);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> tmp=MEDCouplingUMesh::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> tmp2=getCoords()->deepCpy();
  tmp->setCoords(tmp2);
  const double *coo1D=mesh1D->getCoords()->getConstPointer();
  const int *conn1D=mesh1D->getNodalConnectivity()->getConstPointer();
  const int *connI1D=mesh1D->getNodalConnectivityIndex()->getConstPointer();
  for(int i=1;i<nbOfLevsInVec;i++)
    {
      const double *begin=coo1D+3*conn1D[connI1D[i-1]+1];
      const double *end=coo1D+3*conn1D[connI1D[i-1]+2];
      const double *third=i+1<nbOfLevsInVec?coo1D+3*conn1D[connI1D[i]+2]:coo1D+3*conn1D[connI1D[i-2]+1];
      const double vec[3]={end[0]-begin[0],end[1]-begin[1],end[2]-begin[2]};
      tmp->translate(vec);
      double tmp3[2],radius,alpha,alpha0;
      const double *p0=i+1<nbOfLevsInVec?begin:third;
      const double *p1=i+1<nbOfLevsInVec?end:begin;
      const double *p2=i+1<nbOfLevsInVec?third:end;
      double vecPlane[3]={
        (p1[1]-p0[1])*(p2[2]-p1[2])-(p1[2]-p0[2])*(p2[1]-p1[1]),
        (p1[2]-p0[2])*(p2[0]-p1[0])-(p1[0]-p0[0])*(p2[2]-p1[2]),
        (p1[0]-p0[0])*(p2[1]-p1[1])-(p1[1]-p0[1])*(p2[0]-p1[0]),
      };
      double norm=sqrt(vecPlane[0]*vecPlane[0]+vecPlane[1]*vecPlane[1]+vecPlane[2]*vecPlane[2]);
      if(norm>1.e-7)
        {
          vecPlane[0]/=norm; vecPlane[1]/=norm; vecPlane[2]/=norm;
          double norm2=sqrt(vecPlane[0]*vecPlane[0]+vecPlane[1]*vecPlane[1]);
          double vec2[2]={vecPlane[1]/norm2,-vecPlane[0]/norm2};
          double s2=norm2;
          double c2=cos(asin(s2));
          double m[3][3]={
            {vec2[0]*vec2[0]*(1-c2)+c2, vec2[0]*vec2[1]*(1-c2), vec2[1]*s2},
            {vec2[0]*vec2[1]*(1-c2), vec2[1]*vec2[1]*(1-c2)+c2, -vec2[0]*s2},
            {-vec2[1]*s2, vec2[0]*s2, c2}
          };
          double p0r[3]={m[0][0]*p0[0]+m[0][1]*p0[1]+m[0][2]*p0[2], m[1][0]*p0[0]+m[1][1]*p0[1]+m[1][2]*p0[2], m[2][0]*p0[0]+m[2][1]*p0[1]+m[2][2]*p0[2]};
          double p1r[3]={m[0][0]*p1[0]+m[0][1]*p1[1]+m[0][2]*p1[2], m[1][0]*p1[0]+m[1][1]*p1[1]+m[1][2]*p1[2], m[2][0]*p1[0]+m[2][1]*p1[1]+m[2][2]*p1[2]};
          double p2r[3]={m[0][0]*p2[0]+m[0][1]*p2[1]+m[0][2]*p2[2], m[1][0]*p2[0]+m[1][1]*p2[1]+m[1][2]*p2[2], m[2][0]*p2[0]+m[2][1]*p2[1]+m[2][2]*p2[2]};
          INTERP_KERNEL::EdgeArcCircle::GetArcOfCirclePassingThru(p0r,p1r,p2r,tmp3,radius,alpha,alpha0);
          double cosangle=i+1<nbOfLevsInVec?(p0r[0]-tmp3[0])*(p1r[0]-tmp3[0])+(p0r[1]-tmp3[1])*(p1r[1]-tmp3[1]):(p2r[0]-tmp3[0])*(p1r[0]-tmp3[0])+(p2r[1]-tmp3[1])*(p1r[1]-tmp3[1]);
          double angle=acos(cosangle/(radius*radius));
          tmp->rotate(end,vecPlane,angle);
          
        }
      retPtr=std::copy(tmp2->getConstPointer(),tmp2->getConstPointer()+tmp2->getNbOfElems(),retPtr);
    }
  return ret.retn();
}

/*!
 * This method is private because not easy to use for end user. This method is const contrary to
 * MEDCouplingUMesh::buildExtrudedMesh method because this->_coords are expected to contain
 * the coords sorted slice by slice.
 * @param isQuad specifies presence of quadratic cells.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildExtrudedMeshFromThisLowLev(int nbOfNodesOf1Lev, bool isQuad) const
{
  int nbOf1DCells=getNumberOfNodes()/nbOfNodesOf1Lev-1;
  int nbOf2DCells=getNumberOfCells();
  int nbOf3DCells=nbOf2DCells*nbOf1DCells;
  MEDCouplingUMesh *ret=MEDCouplingUMesh::New("Extruded",getMeshDimension()+1);
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConnI->alloc(nbOf3DCells+1,1);
  int *newConnIPtr=newConnI->getPointer();
  *newConnIPtr++=0;
  std::vector<int> newc;
  for(int j=0;j<nbOf2DCells;j++)
    {
      AppendExtrudedCell(conn+connI[j],conn+connI[j+1],nbOfNodesOf1Lev,isQuad,newc);
      *newConnIPtr++=(int)newc.size();
    }
  newConn->alloc((int)(newc.size())*nbOf1DCells,1);
  int *newConnPtr=newConn->getPointer();
  int deltaPerLev=isQuad?2*nbOfNodesOf1Lev:nbOfNodesOf1Lev;
  newConnIPtr=newConnI->getPointer();
  for(int iz=0;iz<nbOf1DCells;iz++)
    {
      if(iz!=0)
        std::transform(newConnIPtr+1,newConnIPtr+1+nbOf2DCells,newConnIPtr+1+iz*nbOf2DCells,std::bind2nd(std::plus<int>(),newConnIPtr[iz*nbOf2DCells]));
      for(std::vector<int>::const_iterator iter=newc.begin();iter!=newc.end();iter++,newConnPtr++)
        {
          int icell=(int)(iter-newc.begin());
          if(std::find(newConnIPtr,newConnIPtr+nbOf2DCells,icell)==newConnIPtr+nbOf2DCells)
            {
              if(*iter!=-1)
                *newConnPtr=(*iter)+iz*deltaPerLev;
              else
                *newConnPtr=-1;
            }
          else
            *newConnPtr=(*iter);
        }
    }
  ret->setConnectivity(newConn,newConnI,true);
  ret->setCoords(getCoords());
  return ret;
}

/*!
 * This method returns if 'this' is constituted by only quadratic cells.
 */
bool MEDCouplingUMesh::isFullyQuadratic() const
{
  checkFullyDefined();
  bool ret=true;
  int nbOfCells=getNumberOfCells();
  for(int i=0;i<nbOfCells && ret;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=getTypeOfCell(i);
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
      ret=cm.isQuadratic();
    }
  return ret;
}

/*!
 * This method returns if there is at least one quadratic cell.
 */
bool MEDCouplingUMesh::isPresenceOfQuadratic() const
{
  checkFullyDefined();
  bool ret=false;
  int nbOfCells=getNumberOfCells();
  for(int i=0;i<nbOfCells && !ret;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=getTypeOfCell(i);
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
      ret=cm.isQuadratic();
    }
  return ret;
}

/*!
 * This method convert quadratic cells to linear cells if any was found.
 * If no such cells exists 'this' remains unchanged.
 */
void MEDCouplingUMesh::convertQuadraticCellsToLinear() throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  int nbOfCells=getNumberOfCells();
  int delta=0;
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=getTypeOfCell(i);
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
      if(cm.isQuadratic())
        {
          INTERP_KERNEL::NormalizedCellType typel=cm.getLinearType();
          const INTERP_KERNEL::CellModel& cml=INTERP_KERNEL::CellModel::GetCellModel(typel);
          delta+=cm.getNumberOfNodes()-cml.getNumberOfNodes();
        }
    }
  if(delta==0)
    return ;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConn->alloc(getMeshLength()-delta,1);
  newConnI->alloc(nbOfCells+1,1);
  const int *icptr=_nodal_connec->getConstPointer();
  const int *iciptr=_nodal_connec_index->getConstPointer();
  int *ocptr=newConn->getPointer();
  int *ociptr=newConnI->getPointer();
  *ociptr=0;
  _types.clear();
  for(int i=0;i<nbOfCells;i++,ociptr++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)icptr[iciptr[i]];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
      if(!cm.isQuadratic())
        {
          _types.insert(type);
          ocptr=std::copy(icptr+iciptr[i],icptr+iciptr[i+1],ocptr);
          ociptr[1]=ociptr[0]+iciptr[i+1]-iciptr[i];
        }
      else
        {
          INTERP_KERNEL::NormalizedCellType typel=cm.getLinearType();
          _types.insert(typel);
          const INTERP_KERNEL::CellModel& cml=INTERP_KERNEL::CellModel::GetCellModel(typel);
          int newNbOfNodes=cml.getNumberOfNodes();
          *ocptr++=(int)typel;
          ocptr=std::copy(icptr+iciptr[i]+1,icptr+iciptr[i]+newNbOfNodes+1,ocptr);
          ociptr[1]=ociptr[0]+newNbOfNodes+1;
        }
    }
  setConnectivity(newConn,newConnI,false);
}

/*!
 * This method converts all linear cell in \a this to quadratic one.
 * Contrary to MEDCouplingUMesh::convertQuadraticCellsToLinear method, here it is needed to specify the target
 * type of cells expected. For example INTERP_KERNEL::NORM_TRI3 can be converted to INTERP_KERNEL::NORM_TRI6 if \a conversionType is equal to 0 (the default)
 * or to INTERP_KERNEL::NORM_TRI7 if \a conversionType is equal to 1. All non linear cells and polyhedron in \a this are let untouched.
 * Contrary to MEDCouplingUMesh::convertQuadraticCellsToLinear method, the coordinates in \a this can be become bigger. All created nodes will be put at the
 * end of the existing coordinates.
 * 
 * \param [in] conversionType specifies the type of conversion expected. Only 0 (default) and 1 are supported presently. 0 those that creates the 'most' simple
 *             corresponding quadratic cells. 1 is those creating the 'most' complex.
 * \return a newly created DataArrayInt instance that the caller should deal with containing cell ids of converted cells.
 * 
 * \throw if \a this is not fully defined. It throws too if \a conversionType is not in [0,1].
 *
 * \sa MEDCouplingUMesh::convertQuadraticCellsToLinear
 */
DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic(int conversionType) throw(INTERP_KERNEL::Exception)
{
  DataArrayInt *conn=0,*connI=0;
  DataArrayDouble *coords=0;
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  checkFullyDefined();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret,connSafe,connISafe;
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coordsSafe;
  int meshDim=getMeshDimension();
  switch(conversionType)
    {
    case 0:
      switch(meshDim)
        {
        case 1:
          ret=convertLinearCellsToQuadratic1D0(conn,connI,coords,types);
          connSafe=conn; connISafe=connI; coordsSafe=coords;
          break;
        case 2:
          ret=convertLinearCellsToQuadratic2D0(conn,connI,coords,types);
          connSafe=conn; connISafe=connI; coordsSafe=coords;
          break;
        case 3:
          ret=convertLinearCellsToQuadratic3D0(conn,connI,coords,types);
          connSafe=conn; connISafe=connI; coordsSafe=coords;
          break;
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::convertLinearCellsToQuadratic : conversion of type 0 mesh dimensions available are [1,2,3] !");
        }
      break;
    case 1:
      {
        switch(meshDim)
        {
        case 1:
          ret=convertLinearCellsToQuadratic1D0(conn,connI,coords,types);//it is not a bug. In 1D policy 0 and 1 are equals
          connSafe=conn; connISafe=connI; coordsSafe=coords;
          break;
        case 2:
          ret=convertLinearCellsToQuadratic2D1(conn,connI,coords,types);
          connSafe=conn; connISafe=connI; coordsSafe=coords;
          break;
        case 3:
          ret=convertLinearCellsToQuadratic3D1(conn,connI,coords,types);
          connSafe=conn; connISafe=connI; coordsSafe=coords;
          break;
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::convertLinearCellsToQuadratic : conversion of type 1 mesh dimensions available are [1,2,3] !");
        }
        break;
      }
    default:
      throw INTERP_KERNEL::Exception("MEDCouplingUMesh::convertLinearCellsToQuadratic : conversion type available are 0 (default, the simplest) and 1 (the most complex) !");
    }
  setConnectivity(connSafe,connISafe,false);
  _types=types;
  setCoords(coordsSafe);
  return ret.retn();
}

/*!
 * Implementes \a conversionType 0 for meshes with meshDim = 1, of MEDCouplingUMesh::convertLinearCellsToQuadratic method.
 * \return a newly created DataArrayInt instance that the caller should deal with containing cell ids of converted cells.
 * \sa MEDCouplingUMesh::convertLinearCellsToQuadratic.
 */
DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic1D0(DataArrayInt *&conn, DataArrayInt *&connI, DataArrayDouble *& coords, std::set<INTERP_KERNEL::NormalizedCellType>& types) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> bary=getBarycenterAndOwner();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New(); newConn->alloc(0,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New(); newConnI->alloc(1,1); newConnI->setIJ(0,0,0);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(0,1);
  int nbOfCells=getNumberOfCells();
  int nbOfNodes=getNumberOfNodes();
  const int *cPtr=_nodal_connec->getConstPointer();
  const int *icPtr=_nodal_connec_index->getConstPointer();
  int lastVal=0,offset=nbOfNodes;
  for(int i=0;i<nbOfCells;i++,icPtr++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)cPtr[*icPtr];
      if(type==INTERP_KERNEL::NORM_SEG2)
        {
          types.insert(INTERP_KERNEL::NORM_SEG3);
          newConn->pushBackSilent((int)INTERP_KERNEL::NORM_SEG3);
          newConn->pushBackValsSilent(cPtr+icPtr[0]+1,cPtr+icPtr[0]+3);
          newConn->pushBackSilent(offset++);
          lastVal+=4;
          newConnI->pushBackSilent(lastVal);
          ret->pushBackSilent(i);
        }
      else
        {
          types.insert(type);
          lastVal+=(icPtr[1]-icPtr[0]);
          newConnI->pushBackSilent(lastVal);
          newConn->pushBackValsSilent(cPtr+icPtr[0],cPtr+icPtr[1]);
        }
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> tmp=bary->selectByTupleIdSafe(ret->begin(),ret->end());
  coords=DataArrayDouble::Aggregate(getCoords(),tmp); conn=newConn.retn(); connI=newConnI.retn();
  return ret.retn();
}

DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic2DAnd3D0(const MEDCouplingUMesh *m1D, const DataArrayInt *desc, const DataArrayInt *descI, DataArrayInt *&conn, DataArrayInt *&connI, DataArrayDouble *& coords, std::set<INTERP_KERNEL::NormalizedCellType>& types) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New(); newConn->alloc(0,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New(); newConnI->alloc(1,1); newConnI->setIJ(0,0,0);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(0,1);
  //
  const int *descPtr(desc->begin()),*descIPtr(descI->begin());
  DataArrayInt *conn1D=0,*conn1DI=0;
  std::set<INTERP_KERNEL::NormalizedCellType> types1D;
  DataArrayDouble *coordsTmp=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret1D=m1D->convertLinearCellsToQuadratic1D0(conn1D,conn1DI,coordsTmp,types1D); ret1D=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coordsTmpSafe(coordsTmp);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn1DSafe(conn1D),conn1DISafe(conn1DI);
  const int *c1DPtr=conn1D->begin();
  const int *c1DIPtr=conn1DI->begin();
  int nbOfCells=getNumberOfCells();
  const int *cPtr=_nodal_connec->getConstPointer();
  const int *icPtr=_nodal_connec_index->getConstPointer();
  int lastVal=0;
  for(int i=0;i<nbOfCells;i++,icPtr++,descIPtr++)
    {
      INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)cPtr[*icPtr];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(typ);
      if(!cm.isQuadratic())
        {
          INTERP_KERNEL::NormalizedCellType typ2=cm.getQuadraticType();
          types.insert(typ2); newConn->pushBackSilent(typ2);
          newConn->pushBackValsSilent(cPtr+icPtr[0]+1,cPtr+icPtr[1]);
          for(const int *d=descPtr+descIPtr[0];d!=descPtr+descIPtr[1];d++)
            newConn->pushBackSilent(c1DPtr[c1DIPtr[*d]+3]);
          lastVal+=(icPtr[1]-icPtr[0])+(descIPtr[1]-descIPtr[0]);
          newConnI->pushBackSilent(lastVal);
          ret->pushBackSilent(i);
        }
      else
        {
          types.insert(typ);
          lastVal+=(icPtr[1]-icPtr[0]);
          newConnI->pushBackSilent(lastVal);
          newConn->pushBackValsSilent(cPtr+icPtr[0],cPtr+icPtr[1]);
        }
    }
  conn=newConn.retn(); connI=newConnI.retn(); coords=coordsTmpSafe.retn();
  return ret.retn();
}

/*!
 * Implementes \a conversionType 0 for meshes with meshDim = 2, of MEDCouplingUMesh::convertLinearCellsToQuadratic method.
 * \return a newly created DataArrayInt instance that the caller should deal with containing cell ids of converted cells.
 * \sa MEDCouplingUMesh::convertLinearCellsToQuadratic.
 */
DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic2D0(DataArrayInt *&conn, DataArrayInt *&connI, DataArrayDouble *& coords, std::set<INTERP_KERNEL::NormalizedCellType>& types) const throw(INTERP_KERNEL::Exception)
{
  
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc(DataArrayInt::New()),descI(DataArrayInt::New()),tmp2(DataArrayInt::New()),tmp3(DataArrayInt::New());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m1D=buildDescendingConnectivity(desc,descI,tmp2,tmp3); tmp2=0; tmp3=0;
  return convertLinearCellsToQuadratic2DAnd3D0(m1D,desc,descI,conn,connI,coords,types);
}

DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic2D1(DataArrayInt *&conn, DataArrayInt *&connI, DataArrayDouble *& coords, std::set<INTERP_KERNEL::NormalizedCellType>& types) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc(DataArrayInt::New()),descI(DataArrayInt::New()),tmp2(DataArrayInt::New()),tmp3(DataArrayInt::New());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m1D=buildDescendingConnectivity(desc,descI,tmp2,tmp3); tmp2=0; tmp3=0;
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New(); newConn->alloc(0,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New(); newConnI->alloc(1,1); newConnI->setIJ(0,0,0);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(0,1);
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> bary=getBarycenterAndOwner();
  const int *descPtr(desc->begin()),*descIPtr(descI->begin());
  DataArrayInt *conn1D=0,*conn1DI=0;
  std::set<INTERP_KERNEL::NormalizedCellType> types1D;
  DataArrayDouble *coordsTmp=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret1D=m1D->convertLinearCellsToQuadratic1D0(conn1D,conn1DI,coordsTmp,types1D); ret1D=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coordsTmpSafe(coordsTmp);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn1DSafe(conn1D),conn1DISafe(conn1DI);
  const int *c1DPtr=conn1D->begin();
  const int *c1DIPtr=conn1DI->begin();
  int nbOfCells=getNumberOfCells();
  const int *cPtr=_nodal_connec->getConstPointer();
  const int *icPtr=_nodal_connec_index->getConstPointer();
  int lastVal=0,offset=coordsTmpSafe->getNumberOfTuples();
  for(int i=0;i<nbOfCells;i++,icPtr++,descIPtr++)
    {
      INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)cPtr[*icPtr];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(typ);
      if(!cm.isQuadratic())
        {
          INTERP_KERNEL::NormalizedCellType typ2=cm.getQuadraticType2();
          types.insert(typ2); newConn->pushBackSilent(typ2);
          newConn->pushBackValsSilent(cPtr+icPtr[0]+1,cPtr+icPtr[1]);
          for(const int *d=descPtr+descIPtr[0];d!=descPtr+descIPtr[1];d++)
            newConn->pushBackSilent(c1DPtr[c1DIPtr[*d]+3]);
          newConn->pushBackSilent(offset+ret->getNumberOfTuples());
          lastVal+=(icPtr[1]-icPtr[0])+(descIPtr[1]-descIPtr[0])+1;
          newConnI->pushBackSilent(lastVal);
          ret->pushBackSilent(i);
        }
      else
        {
          types.insert(typ);
          lastVal+=(icPtr[1]-icPtr[0]);
          newConnI->pushBackSilent(lastVal);
          newConn->pushBackValsSilent(cPtr+icPtr[0],cPtr+icPtr[1]);
        }
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> tmp=bary->selectByTupleIdSafe(ret->begin(),ret->end());
  coords=DataArrayDouble::Aggregate(coordsTmpSafe,tmp); conn=newConn.retn(); connI=newConnI.retn();
  return ret.retn();
}

/*!
 * Implementes \a conversionType 0 for meshes with meshDim = 3, of MEDCouplingUMesh::convertLinearCellsToQuadratic method.
 * \return a newly created DataArrayInt instance that the caller should deal with containing cell ids of converted cells.
 * \sa MEDCouplingUMesh::convertLinearCellsToQuadratic.
 */
DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic3D0(DataArrayInt *&conn, DataArrayInt *&connI, DataArrayDouble *& coords, std::set<INTERP_KERNEL::NormalizedCellType>& types) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc(DataArrayInt::New()),descI(DataArrayInt::New()),tmp2(DataArrayInt::New()),tmp3(DataArrayInt::New());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m1D=explode3DMeshTo1D(desc,descI,tmp2,tmp3); tmp2=0; tmp3=0;
  return convertLinearCellsToQuadratic2DAnd3D0(m1D,desc,descI,conn,connI,coords,types);
}

DataArrayInt *MEDCouplingUMesh::convertLinearCellsToQuadratic3D1(DataArrayInt *&conn, DataArrayInt *&connI, DataArrayDouble *& coords, std::set<INTERP_KERNEL::NormalizedCellType>& types) const throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc2(DataArrayInt::New()),desc2I(DataArrayInt::New()),tmp2(DataArrayInt::New()),tmp3(DataArrayInt::New());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m2D=buildDescendingConnectivityGen<MinusOneSonsGeneratorBiQuadratic>(desc2,desc2I,tmp2,tmp3,MEDCouplingFastNbrer); tmp2=0; tmp3=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc1(DataArrayInt::New()),desc1I(DataArrayInt::New()),tmp4(DataArrayInt::New()),tmp5(DataArrayInt::New());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m1D=explode3DMeshTo1D(desc1,desc1I,tmp4,tmp5); tmp4=0; tmp5=0;
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New(); newConn->alloc(0,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New(); newConnI->alloc(1,1); newConnI->setIJ(0,0,0);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(),ret2=DataArrayInt::New(); ret->alloc(0,1); ret2->alloc(0,1);
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> bary=getBarycenterAndOwner();
  const int *descPtr(desc1->begin()),*descIPtr(desc1I->begin()),*desc2Ptr(desc2->begin()),*desc2IPtr(desc2I->begin());
  DataArrayInt *conn1D=0,*conn1DI=0,*conn2D=0,*conn2DI=0;
  std::set<INTERP_KERNEL::NormalizedCellType> types1D,types2D;
  DataArrayDouble *coordsTmp=0,*coordsTmp2=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret1D=m1D->convertLinearCellsToQuadratic1D0(conn1D,conn1DI,coordsTmp,types1D); ret1D=DataArrayInt::New(); ret1D->alloc(0,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn1DSafe(conn1D),conn1DISafe(conn1DI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coordsTmpSafe(coordsTmp);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret2D=m2D->convertLinearCellsToQuadratic2D1(conn2D,conn2DI,coordsTmp2,types2D); ret2D=DataArrayInt::New(); ret2D->alloc(0,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coordsTmp2Safe(coordsTmp2);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn2DSafe(conn2D),conn2DISafe(conn2DI);
  const int *c1DPtr=conn1D->begin(),*c1DIPtr=conn1DI->begin(),*c2DPtr=conn2D->begin(),*c2DIPtr=conn2DI->begin();
  int nbOfCells=getNumberOfCells();
  const int *cPtr=_nodal_connec->getConstPointer();
  const int *icPtr=_nodal_connec_index->getConstPointer();
  int lastVal=0,offset=coordsTmpSafe->getNumberOfTuples();
  for(int i=0;i<nbOfCells;i++,icPtr++,descIPtr++,desc2IPtr++)
    {
      INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)cPtr[*icPtr];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(typ);
      if(!cm.isQuadratic())
        {
          INTERP_KERNEL::NormalizedCellType typ2=cm.getQuadraticType2();
          if(typ2==INTERP_KERNEL::NORM_ERROR)
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::convertLinearCellsToQuadratic3D1 : On cell #" << i << " the linear cell type does not support advanced quadratization !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
          types.insert(typ2); newConn->pushBackSilent(typ2);
          newConn->pushBackValsSilent(cPtr+icPtr[0]+1,cPtr+icPtr[1]);
          for(const int *d=descPtr+descIPtr[0];d!=descPtr+descIPtr[1];d++)
            newConn->pushBackSilent(c1DPtr[c1DIPtr[*d]+3]);
          for(const int *d=desc2Ptr+desc2IPtr[0];d!=desc2Ptr+desc2IPtr[1];d++)
            {
              int nodeId2=c2DPtr[c2DIPtr[(*d)+1]-1];
              int tmpPos=newConn->getNumberOfTuples();
              newConn->pushBackSilent(nodeId2);
              ret2D->pushBackSilent(nodeId2); ret1D->pushBackSilent(tmpPos);
            }
          newConn->pushBackSilent(offset+ret->getNumberOfTuples());
          lastVal+=(icPtr[1]-icPtr[0])+(descIPtr[1]-descIPtr[0])+(desc2IPtr[1]-desc2IPtr[0])+1;
          newConnI->pushBackSilent(lastVal);
          ret->pushBackSilent(i);
        }
      else
        {
          types.insert(typ);
          lastVal+=(icPtr[1]-icPtr[0]);
          newConnI->pushBackSilent(lastVal);
          newConn->pushBackValsSilent(cPtr+icPtr[0],cPtr+icPtr[1]);
        }
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> diffRet2D=ret2D->getDifferentValues();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> o2nRet2D=diffRet2D->invertArrayN2O2O2N(coordsTmp2Safe->getNumberOfTuples());
  coordsTmp2Safe=coordsTmp2Safe->selectByTupleId(diffRet2D->begin(),diffRet2D->end());
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> tmp=bary->selectByTupleIdSafe(ret->begin(),ret->end());
  std::vector<const DataArrayDouble *> v(3); v[0]=coordsTmpSafe; v[1]=coordsTmp2Safe; v[2]=tmp;
  int *c=newConn->getPointer();
  const int *cI(newConnI->begin());
  for(const int *elt=ret1D->begin();elt!=ret1D->end();elt++)
    c[*elt]=o2nRet2D->getIJ(c[*elt],0)+offset;
  offset=coordsTmp2Safe->getNumberOfTuples();
  for(const int *elt=ret->begin();elt!=ret->end();elt++)
    c[cI[(*elt)+1]-1]+=offset;
  coords=DataArrayDouble::Aggregate(v); conn=newConn.retn(); connI=newConnI.retn();
  return ret.retn();
}

/*!
 * This method tessallates 'this' so that the number of cells remains the same.
 * This method works only for meshes with spaceDim equal to 2 and meshDim equal to 2.
 * If no cells are quadratic in 'this' (INTERP_KERNEL::NORM_QUAD8, INTERP_KERNEL::NORM_TRI6, INTERP_KERNEL::NORM_QPOLYG ) this method will remain unchanged.
 * 
 * \b WARNING this method can lead to a uge amount of nodes if eps is very low.
 * @param eps specifies the maximal angle (in radian) between 2 subedges of polylinized edge constituting the input polygon.
 */
void MEDCouplingUMesh::tessellate2D(double eps) throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=2 || getSpaceDimension()!=2)  
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::tessellate2D works on umeshes with meshdim equal to 2 and spaceDim equal to 2 too!");
  double epsa=fabs(eps);
  if(epsa<std::numeric_limits<double>::min())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::tessellate2DCurve : epsilon is null ! Please specify a higher epsilon. If too tiny it can lead to a huge amount of nodes and memory !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> desc1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> descIndx1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDesc1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revDescIndx1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mDesc=buildDescendingConnectivity2(desc1,descIndx1,revDesc1,revDescIndx1);
  revDesc1=0; revDescIndx1=0;
  mDesc->tessellate2DCurve(eps);
  subDivide2DMesh(mDesc->_nodal_connec->getConstPointer(),mDesc->_nodal_connec_index->getConstPointer(),desc1->getConstPointer(),descIndx1->getConstPointer());
  setCoords(mDesc->getCoords());
}

/*!
 * This method tessallates 'this' so that the number of cells remains the same.
 * This method works only for meshes with spaceDim equal to 2 and meshDim equal to 1.
 * If no cells are quadratic in 'this' (INTERP_KERNEL::NORM_QUAD8, INTERP_KERNEL::NORM_TRI6, INTERP_KERNEL::NORM_QPOLYG ) this method will remain unchanged.
 * 
 * \b WARNING this method can lead to a uge amount of nodes if eps is very low.
 * @param eps specifies the maximal angle (in radian) between 2 subedges of polylinized edge constituting the input polygon.
 */
void MEDCouplingUMesh::tessellate2DCurve(double eps) throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=1 || getSpaceDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::tessellate2DCurve works on umeshes with meshdim equal to 1 and spaceDim equal to 2 too!");
  double epsa=fabs(eps);
  if(epsa<std::numeric_limits<double>::min())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::tessellate2DCurve : epsilon is null ! Please specify a higher epsilon. If too tiny it can lead to a huge amount of nodes and memory !");
  INTERP_KERNEL::QUADRATIC_PLANAR::_arc_detection_precision=1.e-10;
  int nbCells=getNumberOfCells();
  int nbNodes=getNumberOfNodes();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coords=_coords->getConstPointer();
  std::vector<double> addCoo;
  std::vector<int> newConn;//no direct DataArrayInt because interface with Geometric2D
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI(DataArrayInt::New());
  newConnI->alloc(nbCells+1,1);
  int *newConnIPtr=newConnI->getPointer();
  *newConnIPtr=0;
  int tmp1[3];
  INTERP_KERNEL::Node *tmp2[3];
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  for(int i=0;i<nbCells;i++,newConnIPtr++)
    {
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[connI[i]]);
      if(cm.isQuadratic())
        {//assert(connI[i+1]-connI[i]-1==3)
          tmp1[0]=conn[connI[i]+1+0]; tmp1[1]=conn[connI[i]+1+1]; tmp1[2]=conn[connI[i]+1+2];
          tmp2[0]=new INTERP_KERNEL::Node(coords[2*tmp1[0]],coords[2*tmp1[0]+1]);
          tmp2[1]=new INTERP_KERNEL::Node(coords[2*tmp1[1]],coords[2*tmp1[1]+1]);
          tmp2[2]=new INTERP_KERNEL::Node(coords[2*tmp1[2]],coords[2*tmp1[2]+1]);
          INTERP_KERNEL::EdgeArcCircle *eac=INTERP_KERNEL::EdgeArcCircle::BuildFromNodes(tmp2[0],tmp2[2],tmp2[1]);
          if(eac)
            {
              eac->tesselate(tmp1,nbNodes,epsa,newConn,addCoo);
              types.insert((INTERP_KERNEL::NormalizedCellType)newConn[newConnIPtr[0]]);
              delete eac;
              newConnIPtr[1]=(int)newConn.size();
            }
          else
            {
              types.insert(INTERP_KERNEL::NORM_SEG2);
              newConn.push_back(INTERP_KERNEL::NORM_SEG2);
              newConn.insert(newConn.end(),conn+connI[i]+1,conn+connI[i]+3);
              newConnIPtr[1]=newConnIPtr[0]+3;
            }
        }
      else
        {
          types.insert((INTERP_KERNEL::NormalizedCellType)conn[connI[i]]);
          newConn.insert(newConn.end(),conn+connI[i],conn+connI[i+1]);
          newConnIPtr[1]=newConnIPtr[0]+3;
        }
    }
  if(addCoo.empty() && ((int)newConn.size())==_nodal_connec->getNumberOfTuples())//nothing happens during tasselation : no update needed
    return ;
  _types=types;
  DataArrayInt::SetArrayIn(newConnI,_nodal_connec_index);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnArr=DataArrayInt::New();
  newConnArr->alloc((int)newConn.size(),1);
  std::copy(newConn.begin(),newConn.end(),newConnArr->getPointer());
  DataArrayInt::SetArrayIn(newConnArr,_nodal_connec);
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> newCoords=DataArrayDouble::New();
  newCoords->alloc(nbNodes+((int)addCoo.size())/2,2);
  double *work=std::copy(_coords->begin(),_coords->end(),newCoords->getPointer());
  std::copy(addCoo.begin(),addCoo.end(),work);
  DataArrayDouble::SetArrayIn(newCoords,_coords);
  updateTime();
}

/*!
 * This methods modify this by converting each cells into simplex cell, that is too say triangle for meshdim==2 or tetra for meshdim==3.
 * This cut into simplex is performed following the parameter \a policy. This method so typically increases the number of cells of \a this.
 * This method \b keeps the number of nodes \b unchanged. That's why the splitting policy in 3D INTERP_KERNEL::GENERAL_24 and INTERP_KERNEL::GENERAL_48 are not available here.
 * This method returns new2old newly allocated array that specifies a each cell of \a this after the call what was its id it comes.
 * 
 * The semantic of \a policy parameter :
 * - 1 only QUAD4. For QUAD4 the cut is done along 0-2 diagonal for QUAD4
 * - 2 only QUAD4. For QUAD4 the cut is done along 1-3 diagonal for QUAD4
 * - PLANAR_FACE_5 only HEXA8. All HEXA8 are split into 5 TETRA4
 * - PLANAR_FACE_6 only HEXA8. All HEXA8 are split into 6 TETRA4
 */
DataArrayInt *MEDCouplingUMesh::simplexize(int policy) throw(INTERP_KERNEL::Exception)
{
  switch(policy)
    {
    case 0:
      return simplexizePol0();
    case 1:
      return simplexizePol1();
    case (int) INTERP_KERNEL::PLANAR_FACE_5:
      return simplexizePlanarFace5();
    case (int) INTERP_KERNEL::PLANAR_FACE_6:
      return simplexizePlanarFace6();
    default:
      throw INTERP_KERNEL::Exception("MEDCouplingUMesh::simplexize : unrecognized policy ! Must be :\n  - 0 or 1 (only available for meshdim=2) \n  - PLANAR_FACE_5, PLANAR_FACE_6  (only for meshdim=3)");
    }
}

bool MEDCouplingUMesh::areOnlySimplexCells() const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()<1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::areOnlySimplexCells : only available with meshes having a meshdim >= 1 !");
  int nbCells=getNumberOfCells();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbCells;i++)
    {
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[connI[i]]);
      if(!cm.isSimplex())
        return false;
    }
  return true;
}

/*!
 * This method implements policy 0 of virtual method ParaMEDMEM::MEDCouplingUMesh::simplexize.
 */
DataArrayInt *MEDCouplingUMesh::simplexizePol0() throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  if(getMeshDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::simplexizePol0 : this policy is only available for mesh with meshdim == 2 !");
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  int nbOfCutCells=getNumberOfCellsWithType(INTERP_KERNEL::NORM_QUAD4);
  ret->alloc(nbOfCells+nbOfCutCells,1);
  if(nbOfCutCells==0) { ret->iota(0); return ret.retn(); }
  int *retPt=ret->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConnI->alloc(nbOfCells+nbOfCutCells+1,1);
  newConn->alloc(getMeshLength()+3*nbOfCutCells,1);
  int *pt=newConn->getPointer();
  int *ptI=newConnI->getPointer();
  ptI[0]=0;
  const int *oldc=_nodal_connec->getConstPointer();
  const int *ci=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbOfCells;i++,ci++)
    {
      if((INTERP_KERNEL::NormalizedCellType)oldc[ci[0]]==INTERP_KERNEL::NORM_QUAD4)
        {
          const int tmp[8]={(int)INTERP_KERNEL::NORM_TRI3,oldc[ci[0]+1],oldc[ci[0]+2],oldc[ci[0]+3],
                            (int)INTERP_KERNEL::NORM_TRI3,oldc[ci[0]+1],oldc[ci[0]+3],oldc[ci[0]+4]};
          pt=std::copy(tmp,tmp+8,pt);
          ptI[1]=ptI[0]+4;
          ptI[2]=ptI[0]+8;
          *retPt++=i;
          *retPt++=i;
          ptI+=2;
        }
      else
        {
          pt=std::copy(oldc+ci[0],oldc+ci[1],pt);
          ptI[1]=ptI[0]+ci[1]-ci[0];
          ptI++;
          *retPt++=i;
        }
    }
  _nodal_connec->decrRef();
  _nodal_connec=newConn.retn();
  _nodal_connec_index->decrRef();
  _nodal_connec_index=newConnI.retn();
  computeTypes();
  updateTime();
  return ret.retn();
}

/*!
 * This method implements policy 1 of virtual method ParaMEDMEM::MEDCouplingUMesh::simplexize.
 */
DataArrayInt *MEDCouplingUMesh::simplexizePol1() throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  if(getMeshDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::simplexizePol0 : this policy is only available for mesh with meshdim == 2 !");
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  int nbOfCutCells=getNumberOfCellsWithType(INTERP_KERNEL::NORM_QUAD4);
  ret->alloc(nbOfCells+nbOfCutCells,1);
  if(nbOfCutCells==0) { ret->iota(0); return ret.retn(); }
  int *retPt=ret->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConnI->alloc(nbOfCells+nbOfCutCells+1,1);
  newConn->alloc(getMeshLength()+3*nbOfCutCells,1);
  int *pt=newConn->getPointer();
  int *ptI=newConnI->getPointer();
  ptI[0]=0;
  const int *oldc=_nodal_connec->getConstPointer();
  const int *ci=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbOfCells;i++,ci++)
    {
      if((INTERP_KERNEL::NormalizedCellType)oldc[ci[0]]==INTERP_KERNEL::NORM_QUAD4)
        {
          const int tmp[8]={(int)INTERP_KERNEL::NORM_TRI3,oldc[ci[0]+1],oldc[ci[0]+2],oldc[ci[0]+4],
                            (int)INTERP_KERNEL::NORM_TRI3,oldc[ci[0]+2],oldc[ci[0]+3],oldc[ci[0]+4]};
          pt=std::copy(tmp,tmp+8,pt);
          ptI[1]=ptI[0]+4;
          ptI[2]=ptI[0]+8;
          *retPt++=i;
          *retPt++=i;
          ptI+=2;
        }
      else
        {
          pt=std::copy(oldc+ci[0],oldc+ci[1],pt);
          ptI[1]=ptI[0]+ci[1]-ci[0];
          ptI++;
          *retPt++=i;
        }
    }
  _nodal_connec->decrRef();
  _nodal_connec=newConn.retn();
  _nodal_connec_index->decrRef();
  _nodal_connec_index=newConnI.retn();
  computeTypes();
  updateTime();
  return ret.retn();
}

/*!
 * This method implements policy INTERP_KERNEL::PLANAR_FACE_5 of virtual method ParaMEDMEM::MEDCouplingUMesh::simplexize.
 */
DataArrayInt *MEDCouplingUMesh::simplexizePlanarFace5() throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  if(getMeshDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::simplexizePlanarFace5 : this policy is only available for mesh with meshdim == 3 !");
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  int nbOfCutCells=getNumberOfCellsWithType(INTERP_KERNEL::NORM_HEXA8);
  ret->alloc(nbOfCells+4*nbOfCutCells,1);
  if(nbOfCutCells==0) { ret->iota(0); return ret.retn(); }
  int *retPt=ret->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConnI->alloc(nbOfCells+4*nbOfCutCells+1,1);
  newConn->alloc(getMeshLength()+16*nbOfCutCells,1);//21
  int *pt=newConn->getPointer();
  int *ptI=newConnI->getPointer();
  ptI[0]=0;
  const int *oldc=_nodal_connec->getConstPointer();
  const int *ci=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbOfCells;i++,ci++)
    {
      if((INTERP_KERNEL::NormalizedCellType)oldc[ci[0]]==INTERP_KERNEL::NORM_HEXA8)
        {
          for(int j=0;j<5;j++,pt+=5,ptI++)
            {
              pt[0]=(int)INTERP_KERNEL::NORM_TETRA4;
              pt[1]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_5_WO[4*j+0]+1]; pt[2]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_5_WO[4*j+1]+1]; pt[3]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_5_WO[4*j+2]+1]; pt[4]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_5_WO[4*j+3]+1];
              *retPt++=i;
              ptI[1]=ptI[0]+5;
            }
        }
      else
        {
          pt=std::copy(oldc+ci[0],oldc+ci[1],pt);
          ptI[1]=ptI[0]+ci[1]-ci[0];
          ptI++;
          *retPt++=i;
        }
    }
  _nodal_connec->decrRef();
  _nodal_connec=newConn.retn();
  _nodal_connec_index->decrRef();
  _nodal_connec_index=newConnI.retn();
  computeTypes();
  updateTime();
  return ret.retn();
}

/*!
 * This method implements policy INTERP_KERNEL::PLANAR_FACE_6 of virtual method ParaMEDMEM::MEDCouplingUMesh::simplexize.
 */
DataArrayInt *MEDCouplingUMesh::simplexizePlanarFace6() throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  if(getMeshDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::simplexizePlanarFace6 : this policy is only available for mesh with meshdim == 3 !");
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  int nbOfCutCells=getNumberOfCellsWithType(INTERP_KERNEL::NORM_HEXA8);
  ret->alloc(nbOfCells+5*nbOfCutCells,1);
  if(nbOfCutCells==0) { ret->iota(0); return ret.retn(); }
  int *retPt=ret->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConnI=DataArrayInt::New();
  newConnI->alloc(nbOfCells+5*nbOfCutCells+1,1);
  newConn->alloc(getMeshLength()+21*nbOfCutCells,1);
  int *pt=newConn->getPointer();
  int *ptI=newConnI->getPointer();
  ptI[0]=0;
  const int *oldc=_nodal_connec->getConstPointer();
  const int *ci=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbOfCells;i++,ci++)
    {
      if((INTERP_KERNEL::NormalizedCellType)oldc[ci[0]]==INTERP_KERNEL::NORM_HEXA8)
        {
          for(int j=0;j<6;j++,pt+=5,ptI++)
            {
              pt[0]=(int)INTERP_KERNEL::NORM_TETRA4;
              pt[1]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_6_WO[4*j+0]+1]; pt[2]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_6_WO[4*j+1]+1]; pt[3]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_6_WO[4*j+2]+1]; pt[4]=oldc[ci[0]+INTERP_KERNEL::SPLIT_NODES_6_WO[4*j+3]+1];
              *retPt++=i;
              ptI[1]=ptI[0]+5;
            }
        }
      else
        {
          pt=std::copy(oldc+ci[0],oldc+ci[1],pt);
          ptI[1]=ptI[0]+ci[1]-ci[0];
          ptI++;
          *retPt++=i;
        }
    }
  _nodal_connec->decrRef();
  _nodal_connec=newConn.retn();
  _nodal_connec_index->decrRef();
  _nodal_connec_index=newConnI.retn();
  computeTypes();
  updateTime();
  return ret.retn();
}

/*!
 * This private method is used to subdivide edges of a mesh with meshdim==2. If 'this' has no a meshdim equal to 2 an exception will be thrown.
 * This method completly ignore coordinates.
 * @param nodeSubdived is the nodal connectivity of subdivision of edges
 * @param nodeIndxSubdived is the nodal connectivity index of subdivision of edges
 * @param desc is descending connectivity in format specified in MEDCouplingUMesh::buildDescendingConnectivity2
 * @param descIndex is descending connectivity index in format specified in MEDCouplingUMesh::buildDescendingConnectivity2
 */
void MEDCouplingUMesh::subDivide2DMesh(const int *nodeSubdived, const int *nodeIndxSubdived, const int *desc, const int *descIndex) throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::subDivide2DMesh : works only on umesh with meshdim==2 !");
  int nbOfCells=getNumberOfCells();
  int *connI=_nodal_connec_index->getPointer();
  int newConnLgth=0;
  for(int i=0;i<nbOfCells;i++,connI++)
    {
      int offset=descIndex[i];
      int nbOfEdges=descIndex[i+1]-offset;
      //
      bool ddirect=desc[offset+nbOfEdges-1]>0;
      int eedgeId=std::abs(desc[offset+nbOfEdges-1])-1;
      int ref=ddirect?nodeSubdived[nodeIndxSubdived[eedgeId+1]-1]:nodeSubdived[nodeIndxSubdived[eedgeId]+1];
      for(int j=0;j<nbOfEdges;j++)
        {
          bool direct=desc[offset+j]>0;
          int edgeId=std::abs(desc[offset+j])-1;
          if(!INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)nodeSubdived[nodeIndxSubdived[edgeId]]).isQuadratic())
            {
              int id1=nodeSubdived[nodeIndxSubdived[edgeId]+1];
              int id2=nodeSubdived[nodeIndxSubdived[edgeId+1]-1];
              int ref2=direct?id1:id2;
              if(ref==ref2)
                {
                  int nbOfSubNodes=nodeIndxSubdived[edgeId+1]-nodeIndxSubdived[edgeId]-1;
                  newConnLgth+=nbOfSubNodes-1;
                  ref=direct?id2:id1;
                }
              else
                {
                  std::ostringstream oss; oss << "MEDCouplingUMesh::subDivide2DMesh : On polygon #" << i << " edgeid #" << j << " subedges mismatch : end subedge k!=start subedge k+1 !";
                  throw INTERP_KERNEL::Exception(oss.str().c_str());
                }
            }
          else
            {
              throw INTERP_KERNEL::Exception("MEDCouplingUMesh::subDivide2DMesh : this method only subdivides into linear edges !");
            }
        }
      newConnLgth++;//+1 is for cell type
      connI[1]=newConnLgth;
    }
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> newConn=DataArrayInt::New();
  newConn->alloc(newConnLgth,1);
  int *work=newConn->getPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      *work++=INTERP_KERNEL::NORM_POLYGON;
      int offset=descIndex[i];
      int nbOfEdges=descIndex[i+1]-offset;
      for(int j=0;j<nbOfEdges;j++)
        {
          bool direct=desc[offset+j]>0;
          int edgeId=std::abs(desc[offset+j])-1;
          if(direct)
            work=std::copy(nodeSubdived+nodeIndxSubdived[edgeId]+1,nodeSubdived+nodeIndxSubdived[edgeId+1]-1,work);
          else
            {
              int nbOfSubNodes=nodeIndxSubdived[edgeId+1]-nodeIndxSubdived[edgeId]-1;
              std::reverse_iterator<const int *> it(nodeSubdived+nodeIndxSubdived[edgeId+1]);
              work=std::copy(it,it+nbOfSubNodes-1,work);
            }
        }
    }
  DataArrayInt::SetArrayIn(newConn,_nodal_connec);
  _types.clear();
  if(nbOfCells>0)
    _types.insert(INTERP_KERNEL::NORM_POLYGON);
}

/*!
 * This method converts all degenerated cells to simpler cells. For example a NORM_QUAD4 cell consituted from 2 same node id in its
 * nodal connectivity will be transform to a NORM_TRI3 cell.
 * This method works \b only \b on \b linear cells.
 * This method works on nodes ids, that is to say a call to ParaMEDMEM::MEDCouplingUMesh::mergeNodes
 * method could be useful before calling this method in case of presence of several pair of nodes located on same position.
 * This method throws an exception if 'this' is not fully defined (connectivity).
 * This method throws an exception too if a "too" degenerated cell is detected. For example a NORM_TRI3 with 3 times the same node id.
 */
void MEDCouplingUMesh::convertDegeneratedCells() throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()<=1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::convertDegeneratedCells works on umeshes with meshdim equals to 2 or 3 !");
  int nbOfCells=getNumberOfCells();
  if(nbOfCells<1)
    return ;
  int initMeshLgth=getMeshLength();
  int *conn=_nodal_connec->getPointer();
  int *index=_nodal_connec_index->getPointer();
  int posOfCurCell=0;
  int newPos=0;
  int lgthOfCurCell;
  for(int i=0;i<nbOfCells;i++)
    {
      lgthOfCurCell=index[i+1]-posOfCurCell;
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[posOfCurCell];
      int newLgth;
      INTERP_KERNEL::NormalizedCellType newType=INTERP_KERNEL::CellSimplify::simplifyDegeneratedCell(type,conn+posOfCurCell+1,lgthOfCurCell-1,
                                                                                                     conn+newPos+1,newLgth);
      conn[newPos]=newType;
      newPos+=newLgth+1;
      posOfCurCell=index[i+1];
      index[i+1]=newPos;
    }
  if(newPos!=initMeshLgth)
    _nodal_connec->reAlloc(newPos);
  computeTypes();
}

/*!
 * This method checks that all or only polygons (depending 'polyOnly' parameter) 2D cells are correctly oriented relative to 'vec' vector.
 * The 'vec' vector has to have a non nul norm.
 * If not 'cells' parameter will be appended with cellIds of incorrect cells.
 * @throw when 'this' is not a mesh with meshdim==2 and spacedim==3
 */
void MEDCouplingUMesh::are2DCellsNotCorrectlyOriented(const double *vec, bool polyOnly, std::vector<int>& cells) const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=2 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("Invalid mesh to apply are2DCellsNotCorrectlyOriented on it : must be meshDim==2 and spaceDim==3 !");
  int nbOfCells=getNumberOfCells();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coordsPtr=_coords->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[connI[i]];
      if(!polyOnly || (type==INTERP_KERNEL::NORM_POLYGON || type==INTERP_KERNEL::NORM_QPOLYG))
        {
          bool isQuadratic=INTERP_KERNEL::CellModel::GetCellModel(type).isQuadratic();
          if(!IsPolygonWellOriented(isQuadratic,vec,conn+connI[i]+1,conn+connI[i+1],coordsPtr))
            cells.push_back(i);
        }
    }
}

/*!
 * This method orient correctly (if needed) all or only polygons (depending 'polyOnly' parameter)  2D cells are correctly oriented relative to 'vec' vector.
 * The 'vec' vector has to have a non nul norm.
 * @throw when 'this' is not a mesh with meshdim==2 and spacedim==3
 */
void MEDCouplingUMesh::orientCorrectly2DCells(const double *vec, bool polyOnly) throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=2 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("Invalid mesh to apply orientCorrectly2DCells on it : must be meshDim==2 and spaceDim==3 !");
  int nbOfCells=getNumberOfCells();
  int *conn=_nodal_connec->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coordsPtr=_coords->getConstPointer();
  bool isModified=false;
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[connI[i]];
      if(!polyOnly || (type==INTERP_KERNEL::NORM_POLYGON || type==INTERP_KERNEL::NORM_QPOLYG))
        {
          bool isQuadratic=INTERP_KERNEL::CellModel::GetCellModel(type).isQuadratic();
          if(!IsPolygonWellOriented(isQuadratic,vec,conn+connI[i]+1,conn+connI[i+1],coordsPtr))
            {
              isModified=true;
              std::vector<int> tmp(connI[i+1]-connI[i]-2);
              std::copy(conn+connI[i]+2,conn+connI[i+1],tmp.rbegin());
              std::copy(tmp.begin(),tmp.end(),conn+connI[i]+2);
            }
        }
    }
  if(isModified)
    _nodal_connec->declareAsNew();
  updateTime();
}

/*!
 * This method checks that all polyhedrons cells have correctly oriented faces.
 * If not, 'cells' parameter will be appended with cellIds of incorrect cells.
 * @throw when 'this' is not a mesh with meshdim==3 and spacedim==3
 */
void MEDCouplingUMesh::arePolyhedronsNotCorrectlyOriented(std::vector<int>& cells) const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("Invalid mesh to apply arePolyhedronsNotCorrectlyOriented on it : must be meshDim==3 and spaceDim==3 !");
  int nbOfCells=getNumberOfCells();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coordsPtr=_coords->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[connI[i]];
      if(type==INTERP_KERNEL::NORM_POLYHED)
        {
          if(!IsPolyhedronWellOriented(conn+connI[i]+1,conn+connI[i+1],coordsPtr))
            cells.push_back(i);
        }
    }
}

/*!
 * This method tries to orient correctly polhedrons cells.
 * 
 * \throw when 'this' is not a mesh with meshdim==3 and spacedim==3. An exception is also thrown when the attempt of reparation fails.
 * \sa MEDCouplingUMesh::findAndCorrectBadOriented3DCells
 */
void MEDCouplingUMesh::orientCorrectlyPolyhedrons() throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("Invalid mesh to apply orientCorrectlyPolyhedrons on it : must be meshDim==3 and spaceDim==3 !");
  int nbOfCells=getNumberOfCells();
  int *conn=_nodal_connec->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coordsPtr=_coords->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[connI[i]];
      if(type==INTERP_KERNEL::NORM_POLYHED)
        {
          try
            {
              if(!IsPolyhedronWellOriented(conn+connI[i]+1,conn+connI[i+1],coordsPtr))
                TryToCorrectPolyhedronOrientation(conn+connI[i]+1,conn+connI[i+1],coordsPtr);
            }
          catch(INTERP_KERNEL::Exception& e)
            {
              std::ostringstream oss; oss << "Something wrong in polyhedron #" << i << " : " << e.what();
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
    }
  updateTime();
}

/*!
 * This method is expected to be applied on a mesh with spaceDim==3 and meshDim==3. If not an exception will be thrown.
 * This method analyzes only linear extruded 3D cells (NORM_HEXA8,NORM_PENTA6,NORM_HEXGP12...)
 * If some extruded cells does not fulfill the MED norm for extruded cells (first face of 3D cell should be oriented to the exterior of the 3D cell).
 * Some viewers are very careful of that (SMESH), but ParaVis ignore that.
 *
 * \ret a newly allocated int array with one components containing cell ids renumbered to fit the convention of MED (MED file and MEDCoupling)
 * \sa MEDCouplingUMesh::findAndCorrectBadOriented3DCells
 */
DataArrayInt *MEDCouplingUMesh::findAndCorrectBadOriented3DExtrudedCells() throw(INTERP_KERNEL::Exception)
{
  const char msg[]="check3DCellsWellOriented detection works only for 3D cells !";
  if(getMeshDimension()!=3)
    throw INTERP_KERNEL::Exception(msg);
  int spaceDim=getSpaceDimension();
  if(spaceDim!=3)
    throw INTERP_KERNEL::Exception(msg);
  //
  int nbOfCells=getNumberOfCells();
  int *conn=_nodal_connec->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coo=getCoords()->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cells(DataArrayInt::New()); cells->alloc(0,1);
  for(int i=0;i<nbOfCells;i++)
    {
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[connI[i]]);
      if(cm.isExtruded() && !cm.isDynamic() && !cm.isQuadratic())
        {
          if(!Is3DExtrudedStaticCellWellOriented(conn+connI[i]+1,conn+connI[i+1],coo))
            {
              CorrectExtrudedStaticCell(conn+connI[i]+1,conn+connI[i+1]);
              cells->pushBackSilent(i);
            }
        }
    }
  return cells.retn();
}

/*!
 * This method is a faster method to correct orientation of all 3D cells in \a this.
 * This method works only if \a this is a 3D mesh, that is to say a mesh with mesh dimension 3 and a space dimension 3.
 * This method makes the hypothesis that \a this a coherent that is to say MEDCouplingUMesh::checkCoherency2 should throw no exception.
 * 
 * \ret a newly allocated int array with one components containing cell ids renumbered to fit the convention of MED (MED file and MEDCoupling)
 * \sa MEDCouplingUMesh::orientCorrectlyPolyhedrons, 
 */
DataArrayInt *MEDCouplingUMesh::findAndCorrectBadOriented3DCells() throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("Invalid mesh to apply findAndCorrectBadOriented3DCells on it : must be meshDim==3 and spaceDim==3 !");
  int nbOfCells=getNumberOfCells();
  int *conn=_nodal_connec->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coordsPtr=_coords->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(0,1);
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)conn[connI[i]];
      switch(type)
        {
        case INTERP_KERNEL::NORM_TETRA4:
          {
            if(!IsTetra4WellOriented(conn+connI[i]+1,conn+connI[i+1],coordsPtr))
              {
                std::swap(*(conn+connI[i]+2),*(conn+connI[i]+3));
                ret->pushBackSilent(i);
              }
            break;
          }
        case INTERP_KERNEL::NORM_PYRA5:
          {
            if(!IsPyra5WellOriented(conn+connI[i]+1,conn+connI[i+1],coordsPtr))
              {
                std::swap(*(conn+connI[i]+2),*(conn+connI[i]+4));
                ret->pushBackSilent(i);
              }
            break;
          }
        case INTERP_KERNEL::NORM_PENTA6:
        case INTERP_KERNEL::NORM_HEXA8:
        case INTERP_KERNEL::NORM_HEXGP12:
          {
            if(!Is3DExtrudedStaticCellWellOriented(conn+connI[i]+1,conn+connI[i+1],coordsPtr))
              {
                CorrectExtrudedStaticCell(conn+connI[i]+1,conn+connI[i+1]);
                ret->pushBackSilent(i);
              }
            break;
          }
        case INTERP_KERNEL::NORM_POLYHED:
          {
            if(!IsPolyhedronWellOriented(conn+connI[i]+1,conn+connI[i+1],coordsPtr))
              {
                TryToCorrectPolyhedronOrientation(conn+connI[i]+1,conn+connI[i+1],coordsPtr);
                ret->pushBackSilent(i);
              }
            break;
          }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::orientCorrectly3DCells : Your mesh contains type of cell not supported yet ! send mail to anthony.geay@cea.fr to add it !");
        }
    }
  updateTime();
  return ret.retn();
}

/*!
 * This method has a sense for meshes with spaceDim==3 and meshDim==2.
 * If it is not the case an exception will be thrown.
 * This method is fast because the first cell of 'this' is used to compute the plane.
 * @param vec output of size at least 3 used to store the normal vector (with norm equal to Area ) of searched plane.
 * @param pos output of size at least 3 used to store a point owned of searched plane.
 */
void MEDCouplingUMesh::getFastAveragePlaneOfThis(double *vec, double *pos) const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=2 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("Invalid mesh to apply getFastAveragePlaneOfThis on it : must be meshDim==2 and spaceDim==3 !");
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coordsPtr=_coords->getConstPointer();
  INTERP_KERNEL::areaVectorOfPolygon<int,INTERP_KERNEL::ALL_C_MODE>(conn+1,connI[1]-connI[0]-1,coordsPtr,vec);
  std::copy(coordsPtr+3*conn[1],coordsPtr+3*conn[1]+3,pos);
}

/*!
 * The returned newly created field has to be managed by the caller.
 * This method returns a field on cell with no time lying on 'this'. The meshdimension and spacedimension of this are expected to be both in [2,3]. If not an exception will be thrown.
 * This method for the moment only deals with NORM_TRI3, NORM_QUAD4 and NORM_TETRA4 geometric types.
 * If a cell has an another type an exception will be thrown.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::getEdgeRatioField() const throw(INTERP_KERNEL::Exception)
{
  checkCoherency();
  int spaceDim=getSpaceDimension();
  int meshDim=getMeshDimension();
  if(spaceDim!=2 && spaceDim!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getEdgeRatioField : SpaceDimension must be equal to 2 or 3 !");
  if(meshDim!=2 && meshDim!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getEdgeRatioField : MeshDimension must be equal to 2 or 3 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  ret->setMesh(this);
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> arr=DataArrayDouble::New();
  arr->alloc(nbOfCells,1);
  double *pt=arr->getPointer();
  ret->setArray(arr);//In case of throw to avoid mem leaks arr will be used after decrRef.
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coo=_coords->getConstPointer();
  double tmp[12];
  for(int i=0;i<nbOfCells;i++,pt++)
    {
      INTERP_KERNEL::NormalizedCellType t=(INTERP_KERNEL::NormalizedCellType)*conn;
      switch(t)
        {
          case INTERP_KERNEL::NORM_TRI3:
            {
              FillInCompact3DMode(spaceDim,3,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::triEdgeRatio(tmp);
              break;
            }
          case INTERP_KERNEL::NORM_QUAD4:
            {
              FillInCompact3DMode(spaceDim,4,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::quadEdgeRatio(tmp);
              break;
            }
          case INTERP_KERNEL::NORM_TETRA4:
            {
              FillInCompact3DMode(spaceDim,4,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::tetraEdgeRatio(tmp);
              break;
            }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getEdgeRatioField : A cell with not manged type (NORM_TRI3, NORM_QUAD4 and NORM_TETRA4) has been detected !");
        }
      conn+=connI[i+1]-connI[i];
    }
  ret->setName("EdgeRatio");
  ret->synchronizeTimeWithSupport();
  return ret.retn();
}

/*!
 * The returned newly created field has to be managed by the caller.
 * This method returns a field on cell with no time lying on 'this'. The meshdimension and spacedimension of this are expected to be both in [2,3]. If not an exception will be thrown.
 * This method for the moment only deals with NORM_TRI3, NORM_QUAD4 and NORM_TETRA4 geometric types.
 * If a cell has an another type an exception will be thrown.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::getAspectRatioField() const throw(INTERP_KERNEL::Exception)
{
  checkCoherency();
  int spaceDim=getSpaceDimension();
  int meshDim=getMeshDimension();
  if(spaceDim!=2 && spaceDim!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getAspectRatioField : SpaceDimension must be equal to 2 or 3 !");
  if(meshDim!=2 && meshDim!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getAspectRatioField : MeshDimension must be equal to 2 or 3 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  ret->setMesh(this);
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> arr=DataArrayDouble::New();
  arr->alloc(nbOfCells,1);
  double *pt=arr->getPointer();
  ret->setArray(arr);//In case of throw to avoid mem leaks arr will be used after decrRef.
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coo=_coords->getConstPointer();
  double tmp[12];
  for(int i=0;i<nbOfCells;i++,pt++)
    {
      INTERP_KERNEL::NormalizedCellType t=(INTERP_KERNEL::NormalizedCellType)*conn;
      switch(t)
        {
          case INTERP_KERNEL::NORM_TRI3:
            {
              FillInCompact3DMode(spaceDim,3,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::triAspectRatio(tmp);
              break;
            }
          case INTERP_KERNEL::NORM_QUAD4:
            {
              FillInCompact3DMode(spaceDim,4,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::quadAspectRatio(tmp);
              break;
            }
          case INTERP_KERNEL::NORM_TETRA4:
            {
              FillInCompact3DMode(spaceDim,4,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::tetraAspectRatio(tmp);
              break;
            }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getAspectRatioField : A cell with not manged type (NORM_TRI3, NORM_QUAD4 and NORM_TETRA4) has been detected !");
        }
      conn+=connI[i+1]-connI[i];
    }
  ret->setName("AspectRatio");
  ret->synchronizeTimeWithSupport();
  return ret.retn();
}

/*!
 * The returned newly created field has to be managed by the caller.
 * This method returns a field on cell with no time lying on 'this'. The meshdimension must be equal to 2 and the spacedimension must be equal to 3. If not an exception will be thrown.
 * This method for the moment only deals with NORM_QUAD4 geometric type.
 * If a cell has an another type an exception will be thrown.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::getWarpField() const throw(INTERP_KERNEL::Exception)
{
  checkCoherency();
  int spaceDim=getSpaceDimension();
  int meshDim=getMeshDimension();
  if(spaceDim!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getWarpField : SpaceDimension must be equal to 3 !");
  if(meshDim!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getWarpField : MeshDimension must be equal to 2 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  ret->setMesh(this);
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> arr=DataArrayDouble::New();
  arr->alloc(nbOfCells,1);
  double *pt=arr->getPointer();
  ret->setArray(arr);//In case of throw to avoid mem leaks arr will be used after decrRef.
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coo=_coords->getConstPointer();
  double tmp[12];
  for(int i=0;i<nbOfCells;i++,pt++)
    {
      INTERP_KERNEL::NormalizedCellType t=(INTERP_KERNEL::NormalizedCellType)*conn;
      switch(t)
        {
          case INTERP_KERNEL::NORM_QUAD4:
            {
              FillInCompact3DMode(3,4,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::quadWarp(tmp);
              break;
            }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getWarpField : A cell with not manged type (NORM_QUAD4) has been detected !");
        }
      conn+=connI[i+1]-connI[i];
    }
  ret->setName("Warp");
  ret->synchronizeTimeWithSupport();
  return ret.retn();
}

/*!
 * The returned newly created field has to be managed by the caller.
 * This method returns a field on cell with no time lying on 'this'. The meshdimension must be equal to 2 and the spacedimension must be equal to 3. If not an exception will be thrown.
 * This method for the moment only deals with NORM_QUAD4 geometric type.
 * If a cell has an another type an exception will be thrown.
 */
MEDCouplingFieldDouble *MEDCouplingUMesh::getSkewField() const throw(INTERP_KERNEL::Exception)
{
  checkCoherency();
  int spaceDim=getSpaceDimension();
  int meshDim=getMeshDimension();
  if(spaceDim!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getSkewField : SpaceDimension must be equal to 3 !");
  if(meshDim!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getSkewField : MeshDimension must be equal to 2 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=MEDCouplingFieldDouble::New(ON_CELLS,ONE_TIME);
  ret->setMesh(this);
  int nbOfCells=getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> arr=DataArrayDouble::New();
  arr->alloc(nbOfCells,1);
  double *pt=arr->getPointer();
  ret->setArray(arr);//In case of throw to avoid mem leaks arr will be used after decrRef.
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const double *coo=_coords->getConstPointer();
  double tmp[12];
  for(int i=0;i<nbOfCells;i++,pt++)
    {
      INTERP_KERNEL::NormalizedCellType t=(INTERP_KERNEL::NormalizedCellType)*conn;
      switch(t)
        {
          case INTERP_KERNEL::NORM_QUAD4:
            {
              FillInCompact3DMode(3,4,conn+1,coo,tmp);
              *pt=INTERP_KERNEL::quadSkew(tmp);
              break;
            }
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::getSkewField : A cell with not manged type (NORM_QUAD4) has been detected !");
        }
      conn+=connI[i+1]-connI[i];
    }
  ret->setName("Skew");
  ret->synchronizeTimeWithSupport();
  return ret.retn();
}

/*!
 * This method aggregate the bbox of each cell and put it into bbox parameter.
 * @param bbox out parameter of size 2*spacedim*nbOfcells.
 */
void MEDCouplingUMesh::getBoundingBoxForBBTree(std::vector<double>& bbox) const
{
  int spaceDim=getSpaceDimension();
  int nbOfCells=getNumberOfCells();
  bbox.resize(2*nbOfCells*spaceDim);
  for(int i=0;i<nbOfCells*spaceDim;i++)
    {
      bbox[2*i]=std::numeric_limits<double>::max();
      bbox[2*i+1]=-std::numeric_limits<double>::max();
    }
  const double *coordsPtr=_coords->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      int offset=connI[i]+1;
      int nbOfNodesForCell=connI[i+1]-offset;
      for(int j=0;j<nbOfNodesForCell;j++)
        {
          int nodeId=conn[offset+j];
          if(nodeId>=0)
            for(int k=0;k<spaceDim;k++)
              {
                bbox[2*spaceDim*i+2*k]=std::min(bbox[2*spaceDim*i+2*k],coordsPtr[spaceDim*nodeId+k]);
                bbox[2*spaceDim*i+2*k+1]=std::max(bbox[2*spaceDim*i+2*k+1],coordsPtr[spaceDim*nodeId+k]);
              }
        }
    }
}

/// @cond INTERNAL

namespace ParaMEDMEMImpl
{
  class ConnReader
  {
  public:
    ConnReader(const int *c, int val):_conn(c),_val(val) { }
    bool operator() (const int& pos) { return _conn[pos]!=_val; }
  private:
    const int *_conn;
    int _val;
  };

  class ConnReader2
  {
  public:
    ConnReader2(const int *c, int val):_conn(c),_val(val) { }
    bool operator() (const int& pos) { return _conn[pos]==_val; }
  private:
    const int *_conn;
    int _val;
  };
}

/// @endcond

/*!
 * This method expects that 'this' is sorted by types. If not an exception will be thrown.
 * This method returns in the same format as code (see MEDCouplingUMesh::checkTypeConsistencyAndContig or MEDCouplingUMesh::splitProfilePerType) how
 * 'this' is composed in cell types.
 * The returned array is of size 3*n where n is the number of different types present in 'this'. 
 * For every k in [0,n] ret[3*k+2]==0 because it has no sense here. 
 * This parameter is kept only for compatibility with other methode listed above.
 */
std::vector<int> MEDCouplingUMesh::getDistributionOfTypes() const throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *work=connI;
  int nbOfCells=getNumberOfCells();
  std::size_t n=getAllTypes().size();
  std::vector<int> ret(3*n,0); //ret[3*k+2]==0 because it has no sense here
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  for(std::size_t i=0;work!=connI+nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)conn[*work];
      if(types.find(typ)!=types.end())
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::getDistributionOfTypes : Type " << INTERP_KERNEL::CellModel::GetCellModel(typ).getRepr();
          oss << " is not contiguous !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
      types.insert(typ);
      ret[3*i]=typ;
      const int *work2=std::find_if(work+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,typ));
      ret[3*i+1]=(int)std::distance(work,work2);
      work=work2;
    }
  return ret;
}

/*!
 * This method is used to check that this has contiguous cell type in same order than described in 'code'.
 * only for types cell, type node is not managed.
 * Format of 'code' is the following. 'code' should be of size 3*n and non empty. If not an exception is thrown.
 * foreach k in [0,n) on 3*k pos represent the geometric type and 3*k+1 number of elements of type 3*k.
 * 3*k+2 refers if different from -1 the pos in 'idsPerType' to get the corresponding array.
 * If 2 or more same geometric type is in 'code' and exception is thrown too.
 *
 * This method firstly checks
 * If it exists k so that 3*k geometric type is not in geometric types of this an exception will be thrown.
 * If it exists k so that 3*k geometric type exists but the number of consecutive cell types does not match,
 * an exception is thrown too.
 * 
 * If all geometric types in 'code' are exactly those in 'this' null pointer is returned.
 * If it exists a geometric type in 'this' \b not in 'code' \b no exception is thrown 
 * and a DataArrayInt instance is returned that the user has the responsability to deallocate.
 */
DataArrayInt *MEDCouplingUMesh::checkTypeConsistencyAndContig(const std::vector<int>& code, const std::vector<const DataArrayInt *>& idsPerType) const throw(INTERP_KERNEL::Exception)
{
  if(code.empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::checkTypeConsistencyAndContig : code is empty, should not !");
  std::size_t sz=code.size();
  std::size_t n=sz/3;
  if(sz%3!=0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::checkTypeConsistencyAndContig : code size is NOT %3 !");
  std::vector<INTERP_KERNEL::NormalizedCellType> types;
  int nb=0;
  for(std::size_t i=0;i<n;i++)
    if(std::find(types.begin(),types.end(),(INTERP_KERNEL::NormalizedCellType)code[3*i])==types.end())
      {
        types.push_back((INTERP_KERNEL::NormalizedCellType)code[3*i]);
        nb+=code[3*i+1];
        if(_types.find((INTERP_KERNEL::NormalizedCellType)code[3*i])==_types.end())
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::checkTypeConsistencyAndContig : expected geo types not in this !");
      }
  if(types.size()!=n)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::checkTypeConsistencyAndContig : code contains duplication of types in unstructured mesh !");
  if(idsPerType.empty())
    {
      if(!checkConsecutiveCellTypesAndOrder(&types[0],&types[0]+types.size()))
        throw INTERP_KERNEL::Exception("MEDCouplingUMesh::checkTypeConsistencyAndContig : non contiguous type !");
      if(types.size()==_types.size())
        return 0;
    }
  DataArrayInt *ret=DataArrayInt::New();
  ret->alloc(nb,1);
  int *retPtr=ret->getPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  const int *conn=_nodal_connec->getConstPointer();
  int nbOfCells=getNumberOfCells();
  const int *i=connI;
  int kk=0;
  for(std::vector<INTERP_KERNEL::NormalizedCellType>::const_iterator it=types.begin();it!=types.end();it++,kk++)
    {
      i=std::find_if(i,connI+nbOfCells,ParaMEDMEMImpl::ConnReader2(conn,(int)(*it)));
      int offset=(int)std::distance(connI,i);
      if(code[3*kk+2]==-1)
        {
          const int *j=std::find_if(i+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,(int)(*it)));
          std::size_t pos2=std::distance(i,j);
          for(std::size_t k=0;k<pos2;k++)
            *retPtr++=(int)k+offset;
          i=j;
        }
      else
        {
          retPtr=std::transform(idsPerType[code[3*kk+2]]->getConstPointer(),idsPerType[code[3*kk+2]]->getConstPointer()+idsPerType[code[3*kk+2]]->getNbOfElems(),
                                retPtr,std::bind2nd(std::plus<int>(),offset));
        }
    }
  return ret;
}

/*!
 * This method makes the hypothesis that \at this is sorted by type. If not an exception will be thrown.
 * This method is the opposite of MEDCouplingUMesh::checkTypeConsistencyAndContig method. Given a list of cells in \a profile it returns a list of sub-profiles sorted by geo type.
 * The result is put in the array \a idsPerType. In the returned parameter \a code, foreach i \a code[3*i+2] refers (if different from -1) to a location into the \a idsPerType.
 * This method has 1 input \a profile and 3 outputs \a code' \a idsInPflPerType and \a idsPerType.
 * 
 * @param [out] code is a vector of size 3*n where n is the number of different geometric type in \a this \b reduced to the profile \a profile. \a code has exactly the same semantic than in MEDCouplingUMesh::checkTypeConsistencyAndContig method.
 * @param [out] idsInPflPerType is a vector of size of different geometric type in the subpart defined by \a profile of \a this ( equal to \a code.size()/3). For each i,
 *              \a idsInPflPerType[i] stores the tuple ids in \a profile that correspond to the geometric type code[3*i+0]
 * @param [out] idsPerType is a vector of size of different sub profiles needed to be defined to represent the profile \a profile for a given geometric type.
 *              This vector can be empty in case of all geometric type cells are fully covered in ascending in the given input \a profile.
 * @throw if \a profile has not exactly one component. It throws too, if \a profile contains some values not in [0,getNumberOfCells()) or if 'this' is not fully defined
 */
void MEDCouplingUMesh::splitProfilePerType(const DataArrayInt *profile, std::vector<int>& code, std::vector<DataArrayInt *>& idsInPflPerType, std::vector<DataArrayInt *>& idsPerType) const throw(INTERP_KERNEL::Exception)
{
  if(profile->getNumberOfComponents()!=1)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::splitProfilePerType : input profile should have exactly one component !");
  checkConnectivityFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::vector<INTERP_KERNEL::NormalizedCellType> types;
  std::vector<int> typeRangeVals(1);
  for(const int *i=connI;i!=connI+nbOfCells;)
    {
      INTERP_KERNEL::NormalizedCellType curType=(INTERP_KERNEL::NormalizedCellType)conn[*i];
      if(std::find(types.begin(),types.end(),curType)!=types.end())
        {
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::splitProfilePerType : current mesh is not sorted by type !");
        }
      types.push_back(curType);
      i=std::find_if(i+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,(int)curType));
      typeRangeVals.push_back((int)std::distance(connI,i));
    }
  //
  DataArrayInt *castArr=0,*rankInsideCast=0,*castsPresent=0;
  profile->splitByValueRange(&typeRangeVals[0],&typeRangeVals[0]+typeRangeVals.size(),castArr,rankInsideCast,castsPresent);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp0=castArr;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp1=rankInsideCast;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp2=castsPresent;
  //
  int nbOfCastsFinal=castsPresent->getNumberOfTuples();
  code.resize(3*nbOfCastsFinal);
  std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> > idsInPflPerType2;
  std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> > idsPerType2;
  for(int i=0;i<nbOfCastsFinal;i++)
    {
      int castId=castsPresent->getIJ(i,0);
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp3=castArr->getIdsEqual(castId);
      idsInPflPerType2.push_back(tmp3);
      code[3*i]=(int)types[castId];
      code[3*i+1]=tmp3->getNumberOfTuples();
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp4=rankInsideCast->selectByTupleId(tmp3->getConstPointer(),tmp3->getConstPointer()+tmp3->getNumberOfTuples());
      if(tmp4->getNumberOfTuples()!=typeRangeVals[castId+1]-typeRangeVals[castId] || !tmp4->isIdentity())
        {
          tmp4->copyStringInfoFrom(*profile);
          idsPerType2.push_back(tmp4);
          code[3*i+2]=(int)idsPerType2.size()-1;
        }
      else
        {
          code[3*i+2]=-1;
        }
    }
  std::size_t sz2=idsInPflPerType2.size();
  idsInPflPerType.resize(sz2);
  for(std::size_t i=0;i<sz2;i++)
    {
      DataArrayInt *locDa=idsInPflPerType2[i];
      locDa->incrRef();
      idsInPflPerType[i]=locDa;
    }
  std::size_t sz=idsPerType2.size();
  idsPerType.resize(sz);
  for(std::size_t i=0;i<sz;i++)
    {
      DataArrayInt *locDa=idsPerType2[i];
      locDa->incrRef();
      idsPerType[i]=locDa;
    }
}

/*!
 * This method is here too emulate the MEDMEM behaviour on BDC (buildDescendingConnectivity). Hoping this method becomes deprecated very soon.
 * This method make the assumption that 'this' and 'nM1LevMesh' mesh lyies on same coords (same pointer) as MED and MEDMEM does.
 * The following equality should be verified 'nM1LevMesh->getMeshDimension()==this->getMeshDimension()-1'
 * This method returns 5+2 elements. 'desc', 'descIndx', 'revDesc', 'revDescIndx' and 'meshnM1' behaves exactly as ParaMEDMEM::MEDCouplingUMesh::buildDescendingConnectivity except the content as described after. The returned array specifies the n-1 mesh reordered by type as MEDMEM does. 'nM1LevMeshIds' contains the ids in returned 'meshnM1'. Finally 'meshnM1Old2New' contains numbering old2new that is to say the cell #k in coarse 'nM1LevMesh' will have the number ret[k] in returned mesh 'nM1LevMesh' MEDMEM reordered.
 */
MEDCouplingUMesh *MEDCouplingUMesh::emulateMEDMEMBDC(const MEDCouplingUMesh *nM1LevMesh, DataArrayInt *desc, DataArrayInt *descIndx, DataArrayInt *&revDesc, DataArrayInt *&revDescIndx, DataArrayInt *& nM1LevMeshIds, DataArrayInt *&meshnM1Old2New) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  nM1LevMesh->checkFullyDefined();
  if(getMeshDimension()-1!=nM1LevMesh->getMeshDimension())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::emulateMEDMEMBDC : The mesh passed as first argument should have a meshDim equal to this->getMeshDimension()-1 !" );
  if(_coords!=nM1LevMesh->getCoords())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::emulateMEDMEMBDC : 'this' and mesh in first argument should share the same coords : Use tryToShareSameCoords method !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp0=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp1=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret1=buildDescendingConnectivity(desc,descIndx,tmp0,tmp1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret0=ret1->sortCellsInMEDFileFrmt();
  desc->transformWithIndArr(ret0->getConstPointer(),ret0->getConstPointer()+ret0->getNbOfElems());
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> tmp=MEDCouplingUMesh::New();
  tmp->setConnectivity(tmp0,tmp1);
  tmp->renumberCells(ret0->getConstPointer(),false);
  revDesc=tmp->getNodalConnectivity();
  revDescIndx=tmp->getNodalConnectivityIndex();
  DataArrayInt *ret=0;
  if(!ret1->areCellsIncludedIn(nM1LevMesh,2,ret))
    {
      int tmp2;
      ret->getMaxValue(tmp2);
      ret->decrRef();
      std::ostringstream oss; oss << "MEDCouplingUMesh::emulateMEDMEMBDC : input N-1 mesh present a cell not in descending mesh ... Id of cell is " << tmp2 << " !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  nM1LevMeshIds=ret;
  //
  revDesc->incrRef();
  revDescIndx->incrRef();
  ret1->incrRef();
  ret0->incrRef();
  meshnM1Old2New=ret0;
  return ret1;
}

/*!
 * This method sorts cell in this so that cells are sorted by cell type specified by MEDMEM and so for MED file.
 * It avoids to deal with renum in MEDLoader so it is useful for MED file R/W with multi types.
 * This method returns a newly allocated array old2New.
 * This method expects that connectivity of this is set. If not an exception will be thrown. Coordinates are not taken into account.
 */
DataArrayInt *MEDCouplingUMesh::sortCellsInMEDFileFrmt() throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=getRenumArrForConsecutiveCellTypesSpec(MEDMEM_ORDER,MEDMEM_ORDER+N_MEDMEM_ORDER);
  renumberCells(ret->getConstPointer(),false);
  return ret.retn();
}

/*!
 * This methods checks that cells are sorted by their types.
 * This method makes asumption (no check) that connectivity is correctly set before calling.
 */
bool MEDCouplingUMesh::checkConsecutiveCellTypes() const
{
  checkFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::set<INTERP_KERNEL::NormalizedCellType> types;
  for(const int *i=connI;i!=connI+nbOfCells;)
    {
      INTERP_KERNEL::NormalizedCellType curType=(INTERP_KERNEL::NormalizedCellType)conn[*i];
      if(types.find(curType)!=types.end())
        return false;
      types.insert(curType);
      i=std::find_if(i+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,(int)curType));
    }
  return true;
}

/*!
 * This method is a specialization of MEDCouplingUMesh::checkConsecutiveCellTypesAndOrder method that is called here.
 * The geometric type order is specified by MED file.
 * 
 * \sa  MEDCouplingUMesh::checkConsecutiveCellTypesAndOrder
 */
bool MEDCouplingUMesh::checkConsecutiveCellTypesForMEDFileFrmt() const throw(INTERP_KERNEL::Exception)
{
  return checkConsecutiveCellTypesAndOrder(MEDMEM_ORDER,MEDMEM_ORDER+N_MEDMEM_ORDER);
}

/*!
 * This method performs the same job as checkConsecutiveCellTypes except that the order of types sequence is analyzed to check
 * that the order is specified in array defined by [orderBg,orderEnd).
 * If there is some geo types in \a this \b NOT in [ \a orderBg, \a orderEnd ) it is OK (return true) if contiguous.
 * If there is some geo types in [ \a orderBg, \a orderEnd ) \b NOT in \a this it is OK too (return true) if contiguous.
 */
bool MEDCouplingUMesh::checkConsecutiveCellTypesAndOrder(const INTERP_KERNEL::NormalizedCellType *orderBg, const INTERP_KERNEL::NormalizedCellType *orderEnd) const
{
  checkFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  if(nbOfCells==0)
    return true;
  int lastPos=-1;
  std::set<INTERP_KERNEL::NormalizedCellType> sg;
  for(const int *i=connI;i!=connI+nbOfCells;)
    {
      INTERP_KERNEL::NormalizedCellType curType=(INTERP_KERNEL::NormalizedCellType)conn[*i];
      const INTERP_KERNEL::NormalizedCellType *isTypeExists=std::find(orderBg,orderEnd,curType);
      if(isTypeExists!=orderEnd)
        {
          int pos=(int)std::distance(orderBg,isTypeExists);
          if(pos<=lastPos)
            return false;
          lastPos=pos;
          i=std::find_if(i+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,(int)curType));
        }
      else
        {
          if(sg.find(curType)==sg.end())
            {
              i=std::find_if(i+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,(int)curType));
              sg.insert(curType);
            }
          else
            return false;
        }
    }
  return true;
}

/*!
 * This method returns 2 newly allocated DataArrayInt instances. The first is an array of size 'this->getNumberOfCells()' with one component,
 * that tells for each cell the pos of its type in the array on type given in input parameter. The 2nd output parameter is an array with the same
 * number of tuples than input type array and with one component. This 2nd output array gives type by type the number of occurence of type in 'this'.
 */
DataArrayInt *MEDCouplingUMesh::getLevArrPerCellTypes(const INTERP_KERNEL::NormalizedCellType *orderBg, const INTERP_KERNEL::NormalizedCellType *orderEnd, DataArrayInt *&nbPerType) const throw(INTERP_KERNEL::Exception)
{
  checkConnectivityFullyDefined();
  int nbOfCells=getNumberOfCells();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmpa=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmpb=DataArrayInt::New();
  tmpa->alloc(nbOfCells,1);
  tmpb->alloc((int)std::distance(orderBg,orderEnd),1);
  tmpb->fillWithZero();
  int *tmp=tmpa->getPointer();
  int *tmp2=tmpb->getPointer();
  for(const int *i=connI;i!=connI+nbOfCells;i++)
    {
      const INTERP_KERNEL::NormalizedCellType *where=std::find(orderBg,orderEnd,(INTERP_KERNEL::NormalizedCellType)conn[*i]);
      if(where!=orderEnd)
        {
          int pos=(int)std::distance(orderBg,where);
          tmp2[pos]++;
          tmp[std::distance(connI,i)]=pos;
        }
      else
        {
          const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)conn[*i]);
          std::ostringstream oss; oss << "MEDCouplingUMesh::getLevArrPerCellTypes : Cell #" << std::distance(connI,i);
          oss << " has a type " << cm.getRepr() << " not in input array of type !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  nbPerType=tmpb.retn();
  return tmpa.retn();
}

/*!
 * This method is similar to method MEDCouplingUMesh::rearrange2ConsecutiveCellTypes except that the type order is specfied by [orderBg,orderEnd) (as MEDCouplingUMesh::checkConsecutiveCellTypesAndOrder method) and that this method is \b const and performs \b NO permutation in 'this'.
 * This method returns an array of size getNumberOfCells() that gives a renumber array old2New that can be used as input of MEDCouplingMesh::renumberCells.
 * The mesh after this call to MEDCouplingMesh::renumberCells will pass the test of MEDCouplingUMesh::checkConsecutiveCellTypesAndOrder with the same inputs.
 * The returned array minimizes the permutations that is to say the order of cells inside same geometric type remains the same.
 */
DataArrayInt *MEDCouplingUMesh::getRenumArrForConsecutiveCellTypesSpec(const INTERP_KERNEL::NormalizedCellType *orderBg, const INTERP_KERNEL::NormalizedCellType *orderEnd) const throw(INTERP_KERNEL::Exception)
{
  DataArrayInt *nbPerType=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmpa=getLevArrPerCellTypes(orderBg,orderEnd,nbPerType);
  nbPerType->decrRef();
  return tmpa->buildPermArrPerLevel();
}

/*!
 * This method reorganize the cells of 'this' so that the cells with same geometric types are put together.
 * The number of cells remains unchanged after the call of this method.
 * This method tries to minimizes the number of needed permutations. So, this method behaves not exactly as
 * MEDCouplingUMesh::sortCellsInMEDFileFrmt.
 *
 * @return the array giving the correspondance old to new.
 */
DataArrayInt *MEDCouplingUMesh::rearrange2ConsecutiveCellTypes()
{
  checkFullyDefined();
  computeTypes();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::vector<INTERP_KERNEL::NormalizedCellType> types;
  for(const int *i=connI;i!=connI+nbOfCells && (types.size()!=_types.size());)
    if(std::find(types.begin(),types.end(),(INTERP_KERNEL::NormalizedCellType)conn[*i])==types.end())
      {
        INTERP_KERNEL::NormalizedCellType curType=(INTERP_KERNEL::NormalizedCellType)conn[*i];
        types.push_back(curType);
        for(i++;i!=connI+nbOfCells && (INTERP_KERNEL::NormalizedCellType)conn[*i]==curType;i++);
      }
  DataArrayInt *ret=DataArrayInt::New();
  ret->alloc(nbOfCells,1);
  int *retPtr=ret->getPointer();
  std::fill(retPtr,retPtr+nbOfCells,-1);
  int newCellId=0;
  for(std::vector<INTERP_KERNEL::NormalizedCellType>::const_iterator iter=types.begin();iter!=types.end();iter++)
    {
      for(const int *i=connI;i!=connI+nbOfCells;i++)
        if((INTERP_KERNEL::NormalizedCellType)conn[*i]==(*iter))
          retPtr[std::distance(connI,i)]=newCellId++;
    }
  renumberCells(retPtr,false);
  return ret;
}

/*!
 * This method splits 'this' into as mush as untructured meshes that consecutive set of same type cells.
 * So this method has typically a sense if MEDCouplingUMesh::checkConsecutiveCellTypes has a sense.
 * This method makes asumption that connectivity is correctly set before calling.
 */
std::vector<MEDCouplingUMesh *> MEDCouplingUMesh::splitByType() const
{
  checkFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::vector<MEDCouplingUMesh *> ret;
  for(const int *i=connI;i!=connI+nbOfCells;)
    {
      INTERP_KERNEL::NormalizedCellType curType=(INTERP_KERNEL::NormalizedCellType)conn[*i];
      int beginCellId=(int)std::distance(connI,i);
      i=std::find_if(i+1,connI+nbOfCells,ParaMEDMEMImpl::ConnReader(conn,(int)curType));
      int endCellId=(int)std::distance(connI,i);
      int sz=endCellId-beginCellId;
      int *cells=new int[sz];
      for(int j=0;j<sz;j++)
        cells[j]=beginCellId+j;
      MEDCouplingUMesh *m=(MEDCouplingUMesh *)buildPartOfMySelf(cells,cells+sz,true);
      delete [] cells;
      ret.push_back(m);
    }
  return ret;
}

/*!
 * This method takes in input a vector of MEDCouplingUMesh instances lying on the same coordinates with same mesh dimensions.
 * Each mesh in \b ms must be sorted by type with the same order (typically using MEDCouplingUMesh::sortCellsInMEDFileFrmt).
 * This method is particulary useful for MED file interaction. It allows to aggregate several meshes and keeping the type sorting
 * and the track of the permutation by chunk of same geotype cells to retrieve it. The traditional formats old2new and new2old
 * are not used here to avoid the build of big permutation array.
 *
 * \param [in] ms meshes with same mesh dimension lying on the same coords and sorted by type following de the same geometric type order than
 *                those specified in MEDCouplingUMesh::sortCellsInMEDFileFrmt method.
 * \param [out] szOfCellGrpOfSameType is a newly allocated DataArrayInt instance whose number of tuples is equal to the number of chunks of same geotype
 *              in all meshes in \b ms. The accumulation of all values of this array is equal to the number of cells of returned mesh.
 * \param [out] idInMsOfCellGrpOfSameType is a newly allocated DataArrayInt instance having the same size than \b szOfCellGrpOfSameType. This
 *              output array gives for each chunck of same type the corresponding mesh id in \b ms.
 * \return A newly allocated unstructured mesh that is the result of the aggregation on same coords of all meshes in \b ms. This returned mesh
 *         is sorted by type following the geo cell types order of MEDCouplingUMesh::sortCellsInMEDFileFrmt method.
 */
MEDCouplingUMesh *MEDCouplingUMesh::AggregateSortedByTypeMeshesOnSameCoords(const std::vector<const MEDCouplingUMesh *>& ms,
                                                                            DataArrayInt *&szOfCellGrpOfSameType,
                                                                            DataArrayInt *&idInMsOfCellGrpOfSameType) throw(INTERP_KERNEL::Exception)
{
  std::vector<const MEDCouplingUMesh *> ms2;
  for(std::vector<const MEDCouplingUMesh *>::const_iterator it=ms.begin();it!=ms.end();it++)
    if(*it)
      {
        (*it)->checkConnectivityFullyDefined();
        ms2.push_back(*it);
      }
  if(ms2.empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::AggregateSortedByTypeMeshesOnSameCoords : input vector is empty !");
  const DataArrayDouble *refCoo=ms2[0]->getCoords();
  int meshDim=ms2[0]->getMeshDimension();
  std::vector<const MEDCouplingUMesh *> m1ssm;
  std::vector< MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> > m1ssmAuto;
  //
  std::vector<const MEDCouplingUMesh *> m1ssmSingle;
  std::vector< MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> > m1ssmSingleAuto;
  int fake=0,rk=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret1(DataArrayInt::New()),ret2(DataArrayInt::New());
  ret1->alloc(0,1); ret2->alloc(0,1);
  for(std::vector<const MEDCouplingUMesh *>::const_iterator it=ms2.begin();it!=ms2.end();it++,rk++)
    {
      if(meshDim!=(*it)->getMeshDimension())
        throw INTERP_KERNEL::Exception("MEDCouplingUMesh::AggregateSortedByTypeMeshesOnSameCoords : meshdims mismatch !");
      if(refCoo!=(*it)->getCoords())
        throw INTERP_KERNEL::Exception("MEDCouplingUMesh::AggregateSortedByTypeMeshesOnSameCoords : meshes are not shared by a single coordinates coords !");
      std::vector<MEDCouplingUMesh *> sp=(*it)->splitByType();
      std::copy(sp.begin(),sp.end(),std::back_insert_iterator< std::vector<const MEDCouplingUMesh *> >(m1ssm));
      std::copy(sp.begin(),sp.end(),std::back_insert_iterator< std::vector<MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> > >(m1ssmAuto));
      for(std::vector<MEDCouplingUMesh *>::const_iterator it2=sp.begin();it2!=sp.end();it2++)
        {
          MEDCouplingUMesh *singleCell=static_cast<MEDCouplingUMesh *>((*it2)->buildPartOfMySelf(&fake,&fake+1,true));
          m1ssmSingleAuto.push_back(singleCell);
          m1ssmSingle.push_back(singleCell);
          ret1->pushBackSilent((*it2)->getNumberOfCells()); ret2->pushBackSilent(rk);
        }
    }
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m1ssmSingle2=MEDCouplingUMesh::MergeUMeshesOnSameCoords(m1ssmSingle);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> renum=m1ssmSingle2->sortCellsInMEDFileFrmt();
  std::vector<const MEDCouplingUMesh *> m1ssmfinal(m1ssm.size());
  for(std::size_t i=0;i<m1ssm.size();i++)
    m1ssmfinal[renum->getIJ(i,0)]=m1ssm[i];
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret0=MEDCouplingUMesh::MergeUMeshesOnSameCoords(m1ssmfinal);
  szOfCellGrpOfSameType=ret1->renumber(renum->getConstPointer());
  idInMsOfCellGrpOfSameType=ret2->renumber(renum->getConstPointer());
  return ret0.retn();
}

/*!
 * This method returns a newly created DataArrayInt instance.
 * This method retrieves cell ids in [begin,end) that have the type 'type'.
 */
DataArrayInt *MEDCouplingUMesh::keepCellIdsByType(INTERP_KERNEL::NormalizedCellType type, const int *begin, const int *end) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connIndex=_nodal_connec_index->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret(DataArrayInt::New()); ret->alloc(0,1);
  for(const int *w=begin;w!=end;w++)
    if((INTERP_KERNEL::NormalizedCellType)conn[connIndex[*w]]==type)
      ret->pushBackSilent(*w);
  return ret.retn();
}

/*!
 * This method makes the assumption that da->getNumberOfTuples()<this->getNumberOfCells(). This method makes the assumption that ids contained in 'da'
 * are in [0:getNumberOfCells())
 */
DataArrayInt *MEDCouplingUMesh::convertCellArrayPerGeoType(const DataArrayInt *da) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  const int *conn=_nodal_connec->getConstPointer();
  const int *connI=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  std::set<INTERP_KERNEL::NormalizedCellType> types=getAllTypes();
  int *tmp=new int[nbOfCells];
  for(std::set<INTERP_KERNEL::NormalizedCellType>::const_iterator iter=types.begin();iter!=types.end();iter++)
    {
      int j=0;
      for(const int *i=connI;i!=connI+nbOfCells;i++)
        if((INTERP_KERNEL::NormalizedCellType)conn[*i]==(*iter))
          tmp[std::distance(connI,i)]=j++;
    }
  DataArrayInt *ret=DataArrayInt::New();
  ret->alloc(da->getNumberOfTuples(),da->getNumberOfComponents());
  ret->copyStringInfoFrom(*da);
  int *retPtr=ret->getPointer();
  const int *daPtr=da->getConstPointer();
  int nbOfElems=da->getNbOfElems();
  for(int k=0;k<nbOfElems;k++)
    retPtr[k]=tmp[daPtr[k]];
  delete [] tmp;
  return ret;
}

/*!
 * This method reduced number of cells of this by keeping cells whose type is different from 'type' and if type=='type'
 * This method \b works \b for mesh sorted by type.
 * cells whose ids is in 'idsPerGeoType' array.
 * This method conserves coords and name of mesh.
 */
MEDCouplingUMesh *MEDCouplingUMesh::keepSpecifiedCells(INTERP_KERNEL::NormalizedCellType type, const int *idsPerGeoTypeBg, const int *idsPerGeoTypeEnd) const
{
  std::vector<int> code=getDistributionOfTypes();
  std::size_t nOfTypesInThis=code.size()/3;
  int sz=0,szOfType=0;
  for(std::size_t i=0;i<nOfTypesInThis;i++)
    {
      if(code[3*i]!=type)
        sz+=code[3*i+1];
      else
        szOfType=code[3*i+1];
    }
  for(const int *work=idsPerGeoTypeBg;work!=idsPerGeoTypeEnd;work++)
    if(*work<0 || *work>=szOfType)
      {
        std::ostringstream oss; oss << "MEDCouplingUMesh::keepSpecifiedCells : Request on type " << type << " at place #" << std::distance(idsPerGeoTypeBg,work) << " value " << *work;
        oss << ". It should be in [0," << szOfType << ") !";
        throw INTERP_KERNEL::Exception(oss.str().c_str());
      }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> idsTokeep=DataArrayInt::New(); idsTokeep->alloc(sz+(int)std::distance(idsPerGeoTypeBg,idsPerGeoTypeEnd),1);
  int *idsPtr=idsTokeep->getPointer();
  int offset=0;
  for(std::size_t i=0;i<nOfTypesInThis;i++)
    {
      if(code[3*i]!=type)
        for(int j=0;j<code[3*i+1];j++)
          *idsPtr++=offset+j;
      else
        idsPtr=std::transform(idsPerGeoTypeBg,idsPerGeoTypeEnd,idsPtr,std::bind2nd(std::plus<int>(),offset));
      offset+=code[3*i+1];
    }
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=static_cast<MEDCouplingUMesh *>(buildPartOfMySelf(idsTokeep->begin(),idsTokeep->end(),true));
  ret->copyTinyInfoFrom(this);
  return ret.retn();
}

/*!
 * This method returns a vector of size 'this->getNumberOfCells()'.
 * This method retrieves for each cell in 'this' if it is linear (false) or quadratic(true).
 */
std::vector<bool> MEDCouplingUMesh::getQuadraticStatus() const throw(INTERP_KERNEL::Exception)
{
  int ncell=getNumberOfCells();
  std::vector<bool> ret(ncell);
  const int *cI=getNodalConnectivityIndex()->getConstPointer();
  const int *c=getNodalConnectivity()->getConstPointer();
  for(int i=0;i<ncell;i++)
    {
      INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)c[cI[i]];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(typ);
      ret[i]=cm.isQuadratic();
    }
  return ret;
}

/*!
 * Returns a newly created mesh (with ref count ==1) that contains merge of 'this' and 'other'.
 */
MEDCouplingMesh *MEDCouplingUMesh::mergeMyselfWith(const MEDCouplingMesh *other) const
{
  if(other->getType()!=UNSTRUCTURED)
    throw INTERP_KERNEL::Exception("Merge of umesh only available with umesh each other !");
  const MEDCouplingUMesh *otherC=static_cast<const MEDCouplingUMesh *>(other);
  return MergeUMeshes(this,otherC);
}

/*!
 * Returns an array with this->getNumberOfCells() tuples and this->getSpaceDimension() dimension.
 * The false barycenter is computed that is to say barycenter of a cell is computed using average on each
 * components of coordinates of the cell.
 */
DataArrayDouble *MEDCouplingUMesh::getBarycenterAndOwner() const
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> ret=DataArrayDouble::New();
  int spaceDim=getSpaceDimension();
  int nbOfCells=getNumberOfCells();
  ret->alloc(nbOfCells,spaceDim);
  ret->copyStringInfoFrom(*getCoords());
  double *ptToFill=ret->getPointer();
  const int *nodal=_nodal_connec->getConstPointer();
  const int *nodalI=_nodal_connec_index->getConstPointer();
  const double *coor=_coords->getConstPointer();
  for(int i=0;i<nbOfCells;i++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)nodal[nodalI[i]];
      INTERP_KERNEL::computeBarycenter2<int,INTERP_KERNEL::ALL_C_MODE>(type,nodal+nodalI[i]+1,nodalI[i+1]-nodalI[i]-1,coor,spaceDim,ptToFill);
      ptToFill+=spaceDim;
    }
  return ret.retn();
}

/*!
 * This method is similar to MEDCouplingUMesh::getBarycenterAndOwner except that it works on subPart of 'this' without
 * building explicitely it. The input part is defined by an array [begin,end). All ids contained in this array should be less than this->getNumberOfCells().
 * No check of that will be done !
 */
DataArrayDouble *MEDCouplingUMesh::getPartBarycenterAndOwner(const int *begin, const int *end) const
{
  DataArrayDouble *ret=DataArrayDouble::New();
  int spaceDim=getSpaceDimension();
  int nbOfTuple=(int)std::distance(begin,end);
  ret->alloc(nbOfTuple,spaceDim);
  double *ptToFill=ret->getPointer();
  double *tmp=new double[spaceDim];
  const int *nodal=_nodal_connec->getConstPointer();
  const int *nodalI=_nodal_connec_index->getConstPointer();
  const double *coor=_coords->getConstPointer();
  for(const int *w=begin;w!=end;w++)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)nodal[nodalI[*w]];
      INTERP_KERNEL::computeBarycenter2<int,INTERP_KERNEL::ALL_C_MODE>(type,nodal+nodalI[*w]+1,nodalI[*w+1]-nodalI[*w]-1,coor,spaceDim,ptToFill);
      ptToFill+=spaceDim;
    }
  delete [] tmp;
  return ret;
}

/*!
 * This method expects as input a DataArrayDouble non nul instance 'da' that should be allocated. If not an exception is thrown.
 * 
 */
MEDCouplingUMesh *MEDCouplingUMesh::Build0DMeshFromCoords(DataArrayDouble *da) throw(INTERP_KERNEL::Exception)
{
  if(!da)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::Build0DMeshFromCoords : instance of DataArrayDouble must be not null !");
  da->checkAllocated();
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New(da->getName().c_str(),0);
  ret->setCoords(da);
  int nbOfTuples=da->getNumberOfTuples();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> c=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cI=DataArrayInt::New();
  c->alloc(2*nbOfTuples,1);
  cI->alloc(nbOfTuples+1,1);
  int *cp=c->getPointer();
  int *cip=cI->getPointer();
  *cip++=0;
  for(int i=0;i<nbOfTuples;i++)
    {
      *cp++=INTERP_KERNEL::NORM_POINT1;
      *cp++=i;
      *cip++=2*(i+1);
    }
  ret->setConnectivity(c,cI,true);
  return ret.retn();
}

/*!
 * Returns a newly created mesh (with ref count ==1) that contains merge of 'mesh1' and 'other'.
 * The coords of 'mesh2' are added at the end of coords of 'mesh1'.
 */
MEDCouplingUMesh *MEDCouplingUMesh::MergeUMeshes(const MEDCouplingUMesh *mesh1, const MEDCouplingUMesh *mesh2) throw(INTERP_KERNEL::Exception)
{
  std::vector<const MEDCouplingUMesh *> tmp(2);
  tmp[0]=const_cast<MEDCouplingUMesh *>(mesh1); tmp[1]=const_cast<MEDCouplingUMesh *>(mesh2);
  return MergeUMeshes(tmp);
}

/*!
 * This method returns in case of success a mesh constitued from union of all meshes in 'a'.
 * There should be \b no presence of null pointer into 'a'. If any an INTERP_KERNEL::Exception will be thrown.
 * The returned mesh will contain aggregation of nodes in 'a' (in the same order) and aggregation of
 * cells in meshes in 'a' (in the same order too).
 */
MEDCouplingUMesh *MEDCouplingUMesh::MergeUMeshes(std::vector<const MEDCouplingUMesh *>& a) throw(INTERP_KERNEL::Exception)
{
  std::size_t sz=a.size();
  if(sz==0)
    return MergeUMeshesLL(a);
  for(std::size_t ii=0;ii<sz;ii++)
    if(!a[ii])
      {
        std::ostringstream oss; oss << "MEDCouplingUMesh::MergeUMeshes : item #" << ii << " in input array of size "<< sz << " is empty !";
        throw INTERP_KERNEL::Exception(oss.str().c_str());
      }
  std::vector< MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> > bb(sz);
  std::vector< const MEDCouplingUMesh * > aa(sz);
  int spaceDim=-3;
  for(std::size_t i=0;i<sz && spaceDim==-3;i++)
    {
      const MEDCouplingUMesh *cur=a[i];
      const DataArrayDouble *coo=cur->getCoords();
      if(coo)
        spaceDim=coo->getNumberOfComponents();
    }
  if(spaceDim==-3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::MergeUMeshes : no spaceDim specified ! unable to perform merge !");
  for(std::size_t i=0;i<sz;i++)
    {
      bb[i]=a[i]->buildSetInstanceFromThis(spaceDim);
      aa[i]=bb[i];
    }
  return MergeUMeshesLL(aa);
}

/// @cond INTERNAL

MEDCouplingUMesh *MEDCouplingUMesh::MergeUMeshesLL(std::vector<const MEDCouplingUMesh *>& a) throw(INTERP_KERNEL::Exception)
{
  if(a.empty())
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::MergeUMeshes : input array must be NON EMPTY !");
  std::vector<const MEDCouplingUMesh *>::const_iterator it=a.begin();
  int meshDim=(*it)->getMeshDimension();
  int nbOfCells=(*it)->getNumberOfCells();
  int meshLgth=(*it++)->getMeshLength();
  for(;it!=a.end();it++)
    {
      if(meshDim!=(*it)->getMeshDimension())
        throw INTERP_KERNEL::Exception("Mesh dimensions mismatches, MergeUMeshes impossible !");
      nbOfCells+=(*it)->getNumberOfCells();
      meshLgth+=(*it)->getMeshLength();
    }
  std::vector<const MEDCouplingPointSet *> aps(a.size());
  std::copy(a.begin(),a.end(),aps.begin());
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> pts=MergeNodesArray(aps);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New("merge",meshDim);
  ret->setCoords(pts);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> c=DataArrayInt::New();
  c->alloc(meshLgth,1);
  int *cPtr=c->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cI=DataArrayInt::New();
  cI->alloc(nbOfCells+1,1);
  int *cIPtr=cI->getPointer();
  *cIPtr++=0;
  int offset=0;
  int offset2=0;
  for(it=a.begin();it!=a.end();it++)
    {
      int curNbOfCell=(*it)->getNumberOfCells();
      const int *curCI=(*it)->_nodal_connec_index->getConstPointer();
      const int *curC=(*it)->_nodal_connec->getConstPointer();
      cIPtr=std::transform(curCI+1,curCI+curNbOfCell+1,cIPtr,std::bind2nd(std::plus<int>(),offset));
      for(int j=0;j<curNbOfCell;j++)
        {
          const int *src=curC+curCI[j];
          *cPtr++=*src++;
          for(;src!=curC+curCI[j+1];src++,cPtr++)
            {
              if(*src!=-1)
                *cPtr=*src+offset2;
              else
                *cPtr=-1;
            }
        }
      offset+=curCI[curNbOfCell];
      offset2+=(*it)->getNumberOfNodes();
    }
  //
  ret->setConnectivity(c,cI,true);
  return ret.retn();
}

/// @endcond

/*!
 * Idem MergeUMeshes except that 'meshes' are expected to lyie on the same coords and 'meshes' have the same meshdim.
 * 'meshes' must be a non empty vector.
 */
MEDCouplingUMesh *MEDCouplingUMesh::MergeUMeshesOnSameCoords(const MEDCouplingUMesh *mesh1, const MEDCouplingUMesh *mesh2) throw(INTERP_KERNEL::Exception)
{
  std::vector<const MEDCouplingUMesh *> tmp(2);
  tmp[0]=mesh1; tmp[1]=mesh2;
  return MergeUMeshesOnSameCoords(tmp);
}

/*!
 * Idem MergeUMeshes except that 'meshes' are expected to lyie on the same coords and 'meshes' have the same meshdim.
 * 'meshes' must be a non empty vector.
 */
MEDCouplingUMesh *MEDCouplingUMesh::MergeUMeshesOnSameCoords(const std::vector<const MEDCouplingUMesh *>& meshes)
{
  if(meshes.empty())
    throw INTERP_KERNEL::Exception("meshes input parameter is expected to be non empty.");
  for(std::size_t ii=0;ii<meshes.size();ii++)
    if(!meshes[ii])
      {
        std::ostringstream oss; oss << "MEDCouplingUMesh::MergeUMeshesOnSameCoords : item #" << ii << " in input array of size "<< meshes.size() << " is empty !";
        throw INTERP_KERNEL::Exception(oss.str().c_str());
      }
  const DataArrayDouble *coords=meshes.front()->getCoords();
  int meshDim=meshes.front()->getMeshDimension();
  std::vector<const MEDCouplingUMesh *>::const_iterator iter=meshes.begin();
  int meshLgth=0;
  int meshIndexLgth=0;
  for(;iter!=meshes.end();iter++)
    {
      if(coords!=(*iter)->getCoords())
        throw INTERP_KERNEL::Exception("meshes does not share the same coords ! Try using tryToShareSameCoords method !");
      if(meshDim!=(*iter)->getMeshDimension())
        throw INTERP_KERNEL::Exception("Mesh dimensions mismatches, FuseUMeshesOnSameCoords impossible !");
      meshLgth+=(*iter)->getMeshLength();
      meshIndexLgth+=(*iter)->getNumberOfCells();
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> nodal=DataArrayInt::New();
  nodal->alloc(meshLgth,1);
  int *nodalPtr=nodal->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> nodalIndex=DataArrayInt::New();
  nodalIndex->alloc(meshIndexLgth+1,1);
  int *nodalIndexPtr=nodalIndex->getPointer();
  int offset=0;
  for(iter=meshes.begin();iter!=meshes.end();iter++)
    {
      const int *nod=(*iter)->getNodalConnectivity()->getConstPointer();
      const int *index=(*iter)->getNodalConnectivityIndex()->getConstPointer();
      int nbOfCells=(*iter)->getNumberOfCells();
      int meshLgth2=(*iter)->getMeshLength();
      nodalPtr=std::copy(nod,nod+meshLgth2,nodalPtr);
      if(iter!=meshes.begin())
        nodalIndexPtr=std::transform(index+1,index+nbOfCells+1,nodalIndexPtr,std::bind2nd(std::plus<int>(),offset));
      else
        nodalIndexPtr=std::copy(index,index+nbOfCells+1,nodalIndexPtr);
      offset+=meshLgth2;
    }
  MEDCouplingUMesh *ret=MEDCouplingUMesh::New();
  ret->setName("merge");
  ret->setMeshDimension(meshDim);
  ret->setConnectivity(nodal,nodalIndex,true);
  ret->setCoords(coords);
  return ret;
}

/*!
 * This method fuses meshes 'meshes' and returns the fused mesh and the correspondances arrays for each mesh in 'meshes' in returned mesh.
 * If a same cell is detected in several meshes in 'meshes', this cell will appear only once in returned mesh (see ParaMEDMEM::MEDCouplingUMesh::zipConnectivityTraducer for more details)
 *
 * @param meshes input non empty vector containing meshes having same coordiantes array and same mesh dimension.
 * @param compType see MEDCouplingUMesh::zipConnectivityTraducer
 * @param corr output vector with same size as 'meshes' parameter. corr[i] is the correspondance array of mesh meshes[i] in returned mesh.
 *             The arrays contained in 'corr' parameter are returned with refcounter set to one.
 *             To avoid memory leaks the caller have to deal with each instances of DataArrayInt contained in 'corr' parameter.
 * @return The mesh lying on the same coordinates than those in meshes. All cells in 'meshes' are in returned mesh with 
 * @exception if meshes is a empty vector or meshes are not lying on same coordinates or meshes not have the same dimension.
 */
MEDCouplingUMesh *MEDCouplingUMesh::FuseUMeshesOnSameCoords(const std::vector<const MEDCouplingUMesh *>& meshes, int compType, std::vector<DataArrayInt *>& corr)
{
  //All checks are delegated to MergeUMeshesOnSameCoords
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MergeUMeshesOnSameCoords(meshes);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> o2n=ret->zipConnectivityTraducer(compType);
  corr.resize(meshes.size());
  std::size_t nbOfMeshes=meshes.size();
  int offset=0;
  const int *o2nPtr=o2n->getConstPointer();
  for(std::size_t i=0;i<nbOfMeshes;i++)
    {
      DataArrayInt *tmp=DataArrayInt::New();
      int curNbOfCells=meshes[i]->getNumberOfCells();
      tmp->alloc(curNbOfCells,1);
      std::copy(o2nPtr+offset,o2nPtr+offset+curNbOfCells,tmp->getPointer());
      offset+=curNbOfCells;
      tmp->setName(meshes[i]->getName());
      corr[i]=tmp;
    }
  return ret.retn();
}

/*!
 * This method takes in input meshes \b meshes containing no null reference. If any an INTERP_KERNEL::Exception will be thrown.
 * \b meshes should have a good coherency (connectivity and coordinates well defined).
 * All mesh in \b meshes must have the same space dimension. If not an INTERP_KERNEL:Exception will be thrown.
 * But mesh in \b meshes \b can \b have \b different \b mesh \b dimension \b each \b other.
 *
 * This method performs nothing if size of \b meshes is in [0,1].
 * This method is particulary useful in MEDLoader context to build a \ref ParaMEDMEM::MEDFileUMesh "MEDFileUMesh" instance that expects that underlying
 * coordinates DataArrayDouble instance.
 *
 * \param [in,out] meshes : vector containing no null instance of MEDCouplingUMesh that in case of success of this method will be modified.
 */
void MEDCouplingUMesh::PutUMeshesOnSameAggregatedCoords(const std::vector<MEDCouplingUMesh *>& meshes) throw(INTERP_KERNEL::Exception)
{
  std::size_t sz=meshes.size();
  if(sz==0 || sz==1)
    return;
  std::vector< const DataArrayDouble * > coords(meshes.size());
  std::vector< const DataArrayDouble * >::iterator it2=coords.begin();
  for(std::vector<MEDCouplingUMesh *>::const_iterator it=meshes.begin();it!=meshes.end();it++,it2++)
    {
      if((*it))
        {
          (*it)->checkConnectivityFullyDefined();
          const DataArrayDouble *coo=(*it)->getCoords();
          if(coo)
            *it2=coo;
          else
            {
              std::ostringstream oss; oss << " MEDCouplingUMesh::PutUMeshesOnSameAggregatedCoords : Item #" << std::distance(meshes.begin(),it) << " inside the vector of length " << meshes.size();
              oss << " has no coordinate array defined !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
      else
        {
          std::ostringstream oss; oss << " MEDCouplingUMesh::PutUMeshesOnSameAggregatedCoords : Item #" << std::distance(meshes.begin(),it) << " inside the vector of length " << meshes.size();
          oss << " is null !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> res=DataArrayDouble::Aggregate(coords);
  std::vector<MEDCouplingUMesh *>::const_iterator it=meshes.begin();
  int offset=(*it)->getNumberOfNodes();
  (*it++)->setCoords(res);
  for(;it!=meshes.end();it++)
    {
      int oldNumberOfNodes=(*it)->getNumberOfNodes();
      (*it)->setCoords(res);
      (*it)->shiftNodeNumbersInConn(offset);
      offset+=oldNumberOfNodes;
    }
}

/*!
 * This method takes in input meshes \b meshes containing no null reference. If any an INTERP_KERNEL::Exception will be thrown.
 * \b meshes should have a good coherency (connectivity and coordinates well defined).
 * All mesh in \b meshes must have the same space dimension. If not an INTERP_KERNEL:Exception will be thrown.
 * But mesh in \b meshes \b can \b have \b different \b mesh \b dimension \b each \b other.
 * If \b meshes share the same instance of DataArrayDouble as coordinates and that this instance is null, this method do nothing and no exception will be thrown.
 *
 * This method performs nothing if size of \b meshes is empty.
 * This method is particulary useful in MEDLoader context to perform a treatment of a MEDFileUMesh instance on different levels.
 * coordinates DataArrayDouble instance.
 *
 * \param [in,out] meshes :vector containing no null instance of MEDCouplingUMesh sharing the same DataArrayDouble instance of coordinates, that in case of success of this method will be modified.
 * \param [in] eps is the distance in absolute (that should be positive !), so that 2 or more points within a distance of eps will be merged into a single point.
 */
void MEDCouplingUMesh::MergeNodesOnUMeshesSharingSameCoords(const std::vector<MEDCouplingUMesh *>& meshes, double eps) throw(INTERP_KERNEL::Exception)
{
  if(meshes.empty())
    return ;
  std::set<const DataArrayDouble *> s;
  for(std::vector<MEDCouplingUMesh *>::const_iterator it=meshes.begin();it!=meshes.end();it++)
    {
      if(*it)
        s.insert((*it)->getCoords());
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::MergeNodesOnUMeshesSharingSameCoords : In input vector of unstructured meshes of size " << meshes.size() << " the element #" << std::distance(meshes.begin(),it) << " is null !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  if(s.size()!=1)
    {
      std::ostringstream oss; oss << "MEDCouplingUMesh::MergeNodesOnUMeshesSharingSameCoords : In input vector of unstructured meshes of size " << meshes.size() << ", it appears that they do not share the same instance of DataArrayDouble for coordiantes ! tryToShareSameCoordsPermute method can help to reach that !";
      throw INTERP_KERNEL::Exception(oss.str().c_str());
    }
  const DataArrayDouble *coo=*(s.begin());
  if(!coo)
    return;
  //
  DataArrayInt *comm,*commI;
  coo->findCommonTuples(eps,-1,comm,commI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp1(comm),tmp2(commI);
  int oldNbOfNodes=coo->getNumberOfTuples();
  int newNbOfNodes;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> o2n=DataArrayInt::BuildOld2NewArrayFromSurjectiveFormat2(oldNbOfNodes,comm->begin(),commI->begin(),commI->end(),newNbOfNodes);
  if(oldNbOfNodes==newNbOfNodes)
    return ;
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> newCoords=coo->renumberAndReduce(o2n->getConstPointer(),newNbOfNodes);
  for(std::vector<MEDCouplingUMesh *>::const_iterator it=meshes.begin();it!=meshes.end();it++)
    {
      (*it)->renumberNodesInConn(o2n->getConstPointer());
      (*it)->setCoords(newCoords);
    } 
}

/*!
 * This method takes in input a cell defined by its MEDcouplingUMesh connectivity [connBg,connEnd) and returns its extruded cell by inserting the result at the end of ret.
 * @param nbOfNodesPerLev in parameter that specifies the number of nodes of one slice of global dataset
 * @param isQuad specifies the policy of connectivity.
 * @ret in/out parameter in which the result will be append
 */
void MEDCouplingUMesh::AppendExtrudedCell(const int *connBg, const int *connEnd, int nbOfNodesPerLev, bool isQuad, std::vector<int>& ret)
{
  INTERP_KERNEL::NormalizedCellType flatType=(INTERP_KERNEL::NormalizedCellType)connBg[0];
  const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(flatType);
  ret.push_back(cm.getExtrudedType());
  int deltaz=isQuad?2*nbOfNodesPerLev:nbOfNodesPerLev;
  switch(flatType)
    {
    case INTERP_KERNEL::NORM_POINT1:
      {
        ret.push_back(connBg[1]);
        ret.push_back(connBg[1]+nbOfNodesPerLev);
        break;
      }
    case INTERP_KERNEL::NORM_SEG2:
      {
        int conn[4]={connBg[1],connBg[2],connBg[2]+deltaz,connBg[1]+deltaz};
        ret.insert(ret.end(),conn,conn+4);
        break;
      }
    case INTERP_KERNEL::NORM_SEG3:
      {
        int conn[8]={connBg[1],connBg[3],connBg[3]+deltaz,connBg[1]+deltaz,connBg[2],connBg[3]+nbOfNodesPerLev,connBg[2]+deltaz,connBg[1]+nbOfNodesPerLev};
        ret.insert(ret.end(),conn,conn+8);
        break;
      }
    case INTERP_KERNEL::NORM_QUAD4:
      {
        int conn[8]={connBg[1],connBg[2],connBg[3],connBg[4],connBg[1]+deltaz,connBg[2]+deltaz,connBg[3]+deltaz,connBg[4]+deltaz};
        ret.insert(ret.end(),conn,conn+8);
        break;
      }
    case INTERP_KERNEL::NORM_TRI3:
      {
        int conn[6]={connBg[1],connBg[2],connBg[3],connBg[1]+deltaz,connBg[2]+deltaz,connBg[3]+deltaz};
        ret.insert(ret.end(),conn,conn+6);
        break;
      }
    case INTERP_KERNEL::NORM_TRI6:
      {
        int conn[15]={connBg[1],connBg[2],connBg[3],connBg[1]+deltaz,connBg[2]+deltaz,connBg[3]+deltaz,connBg[4],connBg[5],connBg[6],connBg[4]+deltaz,connBg[5]+deltaz,connBg[6]+deltaz,
                      connBg[1]+nbOfNodesPerLev,connBg[2]+nbOfNodesPerLev,connBg[3]+nbOfNodesPerLev};
        ret.insert(ret.end(),conn,conn+15);
        break;
      }
    case INTERP_KERNEL::NORM_QUAD8:
      {
        int conn[20]={
          connBg[1],connBg[2],connBg[3],connBg[4],connBg[1]+deltaz,connBg[2]+deltaz,connBg[3]+deltaz,connBg[4]+deltaz,
          connBg[5],connBg[6],connBg[7],connBg[8],connBg[5]+deltaz,connBg[6]+deltaz,connBg[7]+deltaz,connBg[8]+deltaz,
          connBg[1]+nbOfNodesPerLev,connBg[2]+nbOfNodesPerLev,connBg[3]+nbOfNodesPerLev,connBg[4]+nbOfNodesPerLev
        };
        ret.insert(ret.end(),conn,conn+20);
        break;
      }
    case INTERP_KERNEL::NORM_POLYGON:
      {
        std::back_insert_iterator< std::vector<int> > ii(ret);
        std::copy(connBg+1,connEnd,ii);
        *ii++=-1;
        std::reverse_iterator<const int *> rConnBg(connEnd);
        std::reverse_iterator<const int *> rConnEnd(connBg+1);
        std::transform(rConnBg,rConnEnd,ii,std::bind2nd(std::plus<int>(),deltaz));
        std::size_t nbOfRadFaces=std::distance(connBg+1,connEnd);
        for(std::size_t i=0;i<nbOfRadFaces;i++)
          {
            *ii++=-1;
            int conn[4]={connBg[(i+1)%nbOfRadFaces+1],connBg[i+1],connBg[i+1]+deltaz,connBg[(i+1)%nbOfRadFaces+1]+deltaz};
            std::copy(conn,conn+4,ii);
          }
        break;
      }
    default:
      throw INTERP_KERNEL::Exception("A flat type has been detected that has not its extruded representation !");
    }
}

/*!
 * This static operates only for coords in 3D. The polygon is specfied by its connectivity nodes in [begin,end).
 */
bool MEDCouplingUMesh::IsPolygonWellOriented(bool isQuadratic, const double *vec, const int *begin, const int *end, const double *coords)
{
  double v[3]={0.,0.,0.};
  std::size_t sz=std::distance(begin,end);
  if(isQuadratic)
    sz/=2;
  for(std::size_t i=0;i<sz;i++)
    {
      v[0]+=coords[3*begin[i]+1]*coords[3*begin[(i+1)%sz]+2]-coords[3*begin[i]+2]*coords[3*begin[(i+1)%sz]+1];
      v[1]+=coords[3*begin[i]+2]*coords[3*begin[(i+1)%sz]]-coords[3*begin[i]]*coords[3*begin[(i+1)%sz]+2];
      v[2]+=coords[3*begin[i]]*coords[3*begin[(i+1)%sz]+1]-coords[3*begin[i]+1]*coords[3*begin[(i+1)%sz]];
    }
  return vec[0]*v[0]+vec[1]*v[1]+vec[2]*v[2]>0.;
}

/*!
 * The polyhedron is specfied by its connectivity nodes in [begin,end).
 */
bool MEDCouplingUMesh::IsPolyhedronWellOriented(const int *begin, const int *end, const double *coords)
{
  std::vector<std::pair<int,int> > edges;
  std::size_t nbOfFaces=std::count(begin,end,-1)+1;
  const int *bgFace=begin;
  for(std::size_t i=0;i<nbOfFaces;i++)
    {
      const int *endFace=std::find(bgFace+1,end,-1);
      std::size_t nbOfEdgesInFace=std::distance(bgFace,endFace);
      for(std::size_t j=0;j<nbOfEdgesInFace;j++)
        {
          std::pair<int,int> p1(bgFace[j],bgFace[(j+1)%nbOfEdgesInFace]);
          if(std::find(edges.begin(),edges.end(),p1)!=edges.end())
            return false;
          edges.push_back(p1);
        }
      bgFace=endFace+1;
    }
  return INTERP_KERNEL::calculateVolumeForPolyh2<int,INTERP_KERNEL::ALL_C_MODE>(begin,(int)std::distance(begin,end),coords)>-EPS_FOR_POLYH_ORIENTATION;
}

/*!
 * The 3D extruded static cell (PENTA6,HEXA8,HEXAGP12...) its connectivity nodes in [begin,end).
 */
bool MEDCouplingUMesh::Is3DExtrudedStaticCellWellOriented(const int *begin, const int *end, const double *coords)
{
  double vec0[3],vec1[3];
  std::size_t sz=std::distance(begin,end);
  if(sz%2!=0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::Is3DExtrudedStaticCellWellOriented : the length of nodal connectivity of extruded cell is not even !");
  int nbOfNodes=(int)sz/2;
  INTERP_KERNEL::areaVectorOfPolygon<int,INTERP_KERNEL::ALL_C_MODE>(begin,nbOfNodes,coords,vec0);
  const double *pt0=coords+3*begin[0];
  const double *pt1=coords+3*begin[nbOfNodes];
  vec1[0]=pt1[0]-pt0[0]; vec1[1]=pt1[1]-pt0[1]; vec1[2]=pt1[2]-pt0[2];
  return (vec0[0]*vec1[0]+vec0[1]*vec1[1]+vec0[2]*vec1[2])<0.;
}

void MEDCouplingUMesh::CorrectExtrudedStaticCell(int *begin, int *end)
{
  std::size_t sz=std::distance(begin,end);
  INTERP_KERNEL::AutoPtr<int> tmp=new int[sz];
  std::size_t nbOfNodes(sz/2);
  std::copy(begin,end,(int *)tmp);
  for(std::size_t j=1;j<nbOfNodes;j++)
    {
      begin[j]=tmp[nbOfNodes-j];
      begin[j+nbOfNodes]=tmp[nbOfNodes+nbOfNodes-j];
    }
}

bool MEDCouplingUMesh::IsTetra4WellOriented(const int *begin, const int *end, const double *coords)
{
  std::size_t sz=std::distance(begin,end);
  if(sz!=4)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::IsTetra4WellOriented : Tetra4 cell with not 4 nodes ! Call checkCoherency2 !");
  double vec0[3],vec1[3];
  const double *pt0=coords+3*begin[0],*pt1=coords+3*begin[1],*pt2=coords+3*begin[2],*pt3=coords+3*begin[3];
  vec0[0]=pt1[0]-pt0[0]; vec0[1]=pt1[1]-pt0[1]; vec0[2]=pt1[2]-pt0[2]; vec1[0]=pt2[0]-pt0[0]; vec1[1]=pt2[1]-pt0[1]; vec1[2]=pt2[2]-pt0[2]; 
  return ((vec0[1]*vec1[2]-vec0[2]*vec1[1])*(pt3[0]-pt0[0])+(vec0[2]*vec1[0]-vec0[0]*vec1[2])*(pt3[1]-pt0[1])+(vec0[0]*vec1[1]-vec0[1]*vec1[0])*(pt3[2]-pt0[2]))<0;
}

bool MEDCouplingUMesh::IsPyra5WellOriented(const int *begin, const int *end, const double *coords)
{
  std::size_t sz=std::distance(begin,end);
  if(sz!=5)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::IsPyra5WellOriented : Pyra5 cell with not 5 nodes ! Call checkCoherency2 !");
  double vec0[3];
  INTERP_KERNEL::areaVectorOfPolygon<int,INTERP_KERNEL::ALL_C_MODE>(begin,4,coords,vec0);
  const double *pt0=coords+3*begin[0],*pt1=coords+3*begin[4];
  return (vec0[0]*(pt1[0]-pt0[0])+vec0[1]*(pt1[1]-pt0[1])+vec0[2]*(pt1[2]-pt0[2]))<0.;
}

/*!
 * This method performs a simplyfication of a single polyedron cell. To do that each face of cell whose connectivity is defined by [\b begin, \b end) 
 * is compared with the others in order to find faces in the same plane (with approx of eps). If any, the cells are grouped together and projected to
 * a 2D space.
 *
 * \param [in] eps is a relative precision that allows to establish if some 3D plane are coplanar or not.
 * \param [in] coords the coordinates with nb of components exactly equal to 3
 * \param [in] begin begin of the nodal connectivity (geometric type included) of a single polyhedron cell
 * \param [in] end end of nodal connectivity of a single polyhedron cell (excluded)
 * \param [out] res the result is put at the end of the vector without any alteration of the data.
 */
void MEDCouplingUMesh::SimplifyPolyhedronCell(double eps, const DataArrayDouble *coords, const int *begin, const int *end, DataArrayInt *res) throw(INTERP_KERNEL::Exception)
{
  int nbFaces=std::count(begin+1,end,-1)+1;
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> v=DataArrayDouble::New(); v->alloc(nbFaces,3);
  double *vPtr=v->getPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> p=DataArrayDouble::New(); p->alloc(nbFaces,1);
  double *pPtr=p->getPointer();
  const int *stFaceConn=begin+1;
  for(int i=0;i<nbFaces;i++,vPtr+=3,pPtr++)
    {
      const int *endFaceConn=std::find(stFaceConn,end,-1);
      ComputeVecAndPtOfFace(eps,coords->getConstPointer(),stFaceConn,endFaceConn,vPtr,pPtr);
      stFaceConn=endFaceConn+1;
    }
  pPtr=p->getPointer(); vPtr=v->getPointer();
  DataArrayInt *comm1=0,*commI1=0;
  v->findCommonTuples(eps,-1,comm1,commI1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> comm1Auto(comm1),commI1Auto(commI1);
  const int *comm1Ptr=comm1->getConstPointer();
  const int *commI1Ptr=commI1->getConstPointer();
  int nbOfGrps1=commI1Auto->getNumberOfTuples()-1;
  res->pushBackSilent((int)INTERP_KERNEL::NORM_POLYHED);
  //
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mm=MEDCouplingUMesh::New("",3);
  mm->setCoords(const_cast<DataArrayDouble *>(coords)); mm->allocateCells(1); mm->insertNextCell(INTERP_KERNEL::NORM_POLYHED,(int)std::distance(begin+1,end),begin+1);
  mm->finishInsertingCells();
  //
  for(int i=0;i<nbOfGrps1;i++)
    {
      int vecId=comm1Ptr[commI1Ptr[i]];
      MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> tmpgrp2=p->selectByTupleId(comm1Ptr+commI1Ptr[i],comm1Ptr+commI1Ptr[i+1]);
      DataArrayInt *comm2=0,*commI2=0;
      tmpgrp2->findCommonTuples(eps,-1,comm2,commI2);
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> comm2Auto(comm2),commI2Auto(commI2);
      const int *comm2Ptr=comm2->getConstPointer();
      const int *commI2Ptr=commI2->getConstPointer();
      int nbOfGrps2=commI2Auto->getNumberOfTuples()-1;
      for(int j=0;j<nbOfGrps2;j++)
        {
          if(commI2Ptr[j+1]-commI2Ptr[j]<=1)
            {
              res->insertAtTheEnd(begin,end);
              res->pushBackSilent(-1);
            }
          else
            {
              int pointId=comm1Ptr[commI1Ptr[i]+comm2Ptr[commI2Ptr[j]]];
              MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ids2=comm2->selectByTupleId2(commI2Ptr[j],commI2Ptr[j+1],1);
              ids2->transformWithIndArr(comm1Ptr+commI1Ptr[i],comm1Ptr+commI1Ptr[i+1]);
              DataArrayInt *tmp0=DataArrayInt::New(),*tmp1=DataArrayInt::New(),*tmp2=DataArrayInt::New(),*tmp3=DataArrayInt::New();
              MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mm2=mm->buildDescendingConnectivity(tmp0,tmp1,tmp2,tmp3); tmp0->decrRef(); tmp1->decrRef(); tmp2->decrRef(); tmp3->decrRef();
              MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mm3=static_cast<MEDCouplingUMesh *>(mm2->buildPartOfMySelf(ids2->begin(),ids2->end(),true));
              MEDCouplingAutoRefCountObjectPtr<DataArrayInt> idsNodeTmp=mm3->zipCoordsTraducer();
              MEDCouplingAutoRefCountObjectPtr<DataArrayInt> idsNode=idsNodeTmp->invertArrayO2N2N2O(mm3->getNumberOfNodes());
              const int *idsNodePtr=idsNode->getConstPointer();
              double center[3]; center[0]=pPtr[pointId]*vPtr[3*vecId]; center[1]=pPtr[pointId]*vPtr[3*vecId+1]; center[2]=pPtr[pointId]*vPtr[3*vecId+2];
              double vec[3]; vec[0]=vPtr[3*vecId+1]; vec[1]=-vPtr[3*vecId]; vec[2]=0.;
              double norm=vec[0]*vec[0]+vec[1]*vec[1]+vec[2]*vec[2];
              if(std::abs(norm)>eps)
                {
                  double angle=INTERP_KERNEL::EdgeArcCircle::SafeAsin(norm);
                  mm3->rotate(center,vec,angle);
                }
              mm3->changeSpaceDimension(2);
              MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> mm4=mm3->buildSpreadZonesWithPoly();
              const int *conn4=mm4->getNodalConnectivity()->getConstPointer();
              const int *connI4=mm4->getNodalConnectivityIndex()->getConstPointer();
              int nbOfCells=mm4->getNumberOfCells();
              for(int k=0;k<nbOfCells;k++)
                {
                  int l=0;
                  for(const int *work=conn4+connI4[k]+1;work!=conn4+connI4[k+1];work++,l++)
                    res->pushBackSilent(idsNodePtr[*work]);
                  res->pushBackSilent(-1);
                }
            }
        }
    }
  res->popBackSilent();
}

/*!
 * This method computes the normalized vector of the plane and the pos of the point belonging to the plane and the line defined by the vector going
 * through origin. The plane is defined by its nodal connectivity [\b begin, \b end).
 * 
 * \param [in] eps below that value the dot product of 2 vectors is considered as colinears
 * \param [in] coords coordinates expected to have 3 components.
 * \param [in] begin start of the nodal connectivity of the face.
 * \param [in] end end of the nodal connectivity (excluded) of the face.
 * \param [out] v the normalized vector of size 3
 * \param [out] p the pos of plane
 */
void MEDCouplingUMesh::ComputeVecAndPtOfFace(double eps, const double *coords, const int *begin, const int *end, double *v, double *p) throw(INTERP_KERNEL::Exception)
{
  std::size_t nbPoints=std::distance(begin,end);
  if(nbPoints<3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::ComputeVecAndPtOfFace : < of 3 points in face ! not able to find a plane on that face !");
  double vec[3];
  std::size_t j=0;
  bool refFound=false;
  for(;j<nbPoints-1 && !refFound;j++)
    {
      vec[0]=coords[3*begin[j+1]]-coords[3*begin[j]];
      vec[1]=coords[3*begin[j+1]+1]-coords[3*begin[j]+1];
      vec[2]=coords[3*begin[j+1]+2]-coords[3*begin[j]+2];
      double norm=sqrt(vec[0]*vec[0]+vec[1]*vec[1]+vec[2]*vec[2]);
      if(norm>eps)
        {
          refFound=true;
          vec[0]/=norm; vec[1]/=norm; vec[2]/=norm;
        }
    }
  for(std::size_t i=j;i<nbPoints-1;i++)
    {
      double curVec[3];
      curVec[0]=coords[3*begin[i+1]]-coords[3*begin[i]];
      curVec[1]=coords[3*begin[i+1]+1]-coords[3*begin[i]+1];
      curVec[2]=coords[3*begin[i+1]+2]-coords[3*begin[i]+2];
      double norm=sqrt(curVec[0]*curVec[0]+curVec[1]*curVec[1]+curVec[2]*curVec[2]);
      if(norm<eps)
        continue;
      curVec[0]/=norm; curVec[1]/=norm; curVec[2]/=norm;
      v[0]=vec[1]*curVec[2]-vec[2]*curVec[1]; v[1]=vec[2]*curVec[0]-vec[0]*curVec[2]; v[2]=vec[0]*curVec[1]-vec[1]*curVec[0];
      norm=sqrt(v[0]*v[0]+v[1]*v[1]+v[2]*v[2]);
      if(norm>eps)
        {
          v[0]/=norm; v[1]/=norm; v[2]/=norm;
          *p=v[0]*coords[3*begin[i]]+v[1]*coords[3*begin[i]+1]+v[2]*coords[3*begin[i]+2];
          return ;
        }
    }
  throw INTERP_KERNEL::Exception("Not able to find a normal vector of that 3D face !");
}

/*!
 * This method tries to obtain a well oriented polyhedron.
 * If the algorithm fails, an exception will be thrown.
 */
void MEDCouplingUMesh::TryToCorrectPolyhedronOrientation(int *begin, int *end, const double *coords) throw(INTERP_KERNEL::Exception)
{
  std::list< std::pair<int,int> > edgesOK,edgesFinished;
  std::size_t nbOfFaces=std::count(begin,end,-1)+1;
  std::vector<bool> isPerm(nbOfFaces,false);//field on faces False: I don't know, True : oriented
  isPerm[0]=true;
  int *bgFace=begin,*endFace=std::find(begin+1,end,-1);
  std::size_t nbOfEdgesInFace=std::distance(bgFace,endFace);
  for(std::size_t l=0;l<nbOfEdgesInFace;l++) { std::pair<int,int> p1(bgFace[l],bgFace[(l+1)%nbOfEdgesInFace]); edgesOK.push_back(p1); }
  //
  while(std::find(isPerm.begin(),isPerm.end(),false)!=isPerm.end())
    {
      bgFace=begin;
      std::size_t smthChanged=0;
      for(std::size_t i=0;i<nbOfFaces;i++)
        {
          endFace=std::find(bgFace+1,end,-1);
          nbOfEdgesInFace=std::distance(bgFace,endFace);
          if(!isPerm[i])
            {
              bool b;
              for(std::size_t j=0;j<nbOfEdgesInFace;j++)
                {
                  std::pair<int,int> p1(bgFace[j],bgFace[(j+1)%nbOfEdgesInFace]);
                  std::pair<int,int> p2(p1.second,p1.first);
                  bool b1=std::find(edgesOK.begin(),edgesOK.end(),p1)!=edgesOK.end();
                  bool b2=std::find(edgesOK.begin(),edgesOK.end(),p2)!=edgesOK.end();
                  if(b1 || b2) { b=b2; isPerm[i]=true; smthChanged++; break; }
                }
              if(isPerm[i])
                { 
                  if(!b)
                    std::reverse(bgFace+1,endFace);
                  for(std::size_t j=0;j<nbOfEdgesInFace;j++)
                    {
                      std::pair<int,int> p1(bgFace[j],bgFace[(j+1)%nbOfEdgesInFace]);
                      std::pair<int,int> p2(p1.second,p1.first);
                      if(std::find(edgesOK.begin(),edgesOK.end(),p1)!=edgesOK.end())
                        { std::ostringstream oss; oss << "Face #" << j << " of polyhedron looks bad !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
                      if(std::find(edgesFinished.begin(),edgesFinished.end(),p1)!=edgesFinished.end() || std::find(edgesFinished.begin(),edgesFinished.end(),p2)!=edgesFinished.end())
                        { std::ostringstream oss; oss << "Face #" << j << " of polyhedron looks bad !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
                      std::list< std::pair<int,int> >::iterator it=std::find(edgesOK.begin(),edgesOK.end(),p2);
                      if(it!=edgesOK.end())
                        {
                          edgesOK.erase(it);
                          edgesFinished.push_back(p1);
                        }
                      else
                        edgesOK.push_back(p1);
                    }
                }
            }
          bgFace=endFace+1;
        }
      if(smthChanged==0)
        { throw INTERP_KERNEL::Exception("The polyhedron looks too bad to be repaired !"); }
    }
  if(!edgesOK.empty())
    { throw INTERP_KERNEL::Exception("The polyhedron looks too bad to be repaired : Some edges are shared only once !"); }
  if(INTERP_KERNEL::calculateVolumeForPolyh2<int,INTERP_KERNEL::ALL_C_MODE>(begin,(int)std::distance(begin,end),coords)<-EPS_FOR_POLYH_ORIENTATION)
    {//not lucky ! The first face was not correctly oriented : reorient all faces...
      bgFace=begin;
      for(std::size_t i=0;i<nbOfFaces;i++)
        {
          endFace=std::find(bgFace+1,end,-1);
          std::reverse(bgFace+1,endFace);
          bgFace=endFace+1;
        }
    }
}

/*!
 * This method makes the assumption spacedimension == meshdimension == 2.
 * This method works only for linear cells.
 * 
 * \return a newly allocated array containing the connectivity of a polygon type enum included (NORM_POLYGON in pos#0)
 */
DataArrayInt *MEDCouplingUMesh::buildUnionOf2DMesh() const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=2 || getSpaceDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildUnionOf2DMesh : meshdimension, spacedimension must be equal to 2 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m=computeSkin();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> o2n=m->zipCoordsTraducer();
  int nbOfNodesExpected=m->getNumberOfNodes();
  if(m->getNumberOfCells()!=nbOfNodesExpected)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildUnionOf2DMesh : the mesh 2D in input appears to be not in a single part or a quadratic 2D mesh !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> n2o=o2n->invertArrayO2N2N2O(m->getNumberOfNodes());
  const int *n2oPtr=n2o->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> revNodal(DataArrayInt::New()),revNodalI(DataArrayInt::New());
  m->getReverseNodalConnectivity(revNodal,revNodalI);
  const int *revNodalPtr=revNodal->getConstPointer(),*revNodalIPtr=revNodalI->getConstPointer();
  const int *nodalPtr=m->getNodalConnectivity()->getConstPointer();
  const int *nodalIPtr=m->getNodalConnectivityIndex()->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(nbOfNodesExpected+1,1);
  int *work=ret->getPointer();  *work++=INTERP_KERNEL::NORM_POLYGON;
  if(nbOfNodesExpected<1)
    return ret.retn();
  int prevCell=0;
  int prevNode=nodalPtr[nodalIPtr[0]+1];
  *work++=n2oPtr[prevNode];
  for(int i=1;i<nbOfNodesExpected;i++)
    {
      if(nodalIPtr[prevCell+1]-nodalIPtr[prevCell]==3)
        {
          std::set<int> conn(nodalPtr+nodalIPtr[prevCell]+1,nodalPtr+nodalIPtr[prevCell]+3);
          conn.erase(prevNode);
          if(conn.size()==1)
            {
              int curNode=*(conn.begin());
              *work++=n2oPtr[curNode];
              std::set<int> shar(revNodalPtr+revNodalIPtr[curNode],revNodalPtr+revNodalIPtr[curNode+1]);
              shar.erase(prevCell);
              if(shar.size()==1)
                {
                  prevCell=*(shar.begin());
                  prevNode=curNode;
                }
              else
                throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildUnionOf2DMesh : presence of unexpected 2 !");
            }
          else
            throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildUnionOf2DMesh : presence of unexpected 1 !");
        }
      else
        throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildUnionOf2DMesh : presence of unexpected cell !");
    }
  return ret.retn();
}

/*!
 * This method makes the assumption spacedimension == meshdimension == 3.
 * This method works only for linear cells.
 * 
 * \return a newly allocated array containing the connectivity of a polygon type enum included (NORM_POLYHED in pos#0)
 */
DataArrayInt *MEDCouplingUMesh::buildUnionOf3DMesh() const throw(INTERP_KERNEL::Exception)
{
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildUnionOf3DMesh : meshdimension, spacedimension must be equal to 2 !");
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> m=computeSkin();
  const int *conn=m->getNodalConnectivity()->getConstPointer();
  const int *connI=m->getNodalConnectivityIndex()->getConstPointer();
  int nbOfCells=m->getNumberOfCells();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(m->getNodalConnectivity()->getNumberOfTuples(),1);
  int *work=ret->getPointer();  *work++=INTERP_KERNEL::NORM_POLYHED;
  if(nbOfCells<1)
    return ret.retn();
  work=std::copy(conn+connI[0]+1,conn+connI[1],work);
  for(int i=1;i<nbOfCells;i++)
    {
      *work++=-1;
      work=std::copy(conn+connI[i]+1,conn+connI[i+1],work);
    }
  return ret.retn();
}

/*!
 * This method put in zip format into parameter 'zipFrmt' in full interlace mode.
 * This format is often asked by INTERP_KERNEL algorithms to avoid many indirections into coordinates array.
 */
void MEDCouplingUMesh::FillInCompact3DMode(int spaceDim, int nbOfNodesInCell, const int *conn, const double *coo, double *zipFrmt) throw(INTERP_KERNEL::Exception)
{
  double *w=zipFrmt;
  if(spaceDim==3)
    for(int i=0;i<nbOfNodesInCell;i++)
      w=std::copy(coo+3*conn[i],coo+3*conn[i]+3,w);
  else if(spaceDim==2)
    {
      for(int i=0;i<nbOfNodesInCell;i++)
        {
          w=std::copy(coo+2*conn[i],coo+2*conn[i]+2,w);
          *w++=0.;
        }
    }
  else
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::FillInCompact3DMode : Invalid spaceDim specified : must be 2 or 3 !");
}

void MEDCouplingUMesh::writeVTKLL(std::ostream& ofs, const std::string& cellData, const std::string& pointData) const throw(INTERP_KERNEL::Exception)
{
  int nbOfCells=getNumberOfCells();
  if(nbOfCells<=0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::writeVTK : the unstructured mesh has no cells !");
  static const int PARAMEDMEM2VTKTYPETRADUCER[INTERP_KERNEL::NORM_MAXTYPE+1]={1,3,21,5,9,7,22,34,23,28,-1,-1,-1,-1,10,14,13,-1,12,-1,24,-1,16,27,-1,26,-1,29,-1,-1,25,42,-1,4};
  ofs << "  <" << getVTKDataSetType() << ">\n";
  ofs << "    <Piece NumberOfPoints=\"" << getNumberOfNodes() << "\" NumberOfCells=\"" << nbOfCells << "\">\n";
  ofs << "      <PointData>\n" << pointData << std::endl;
  ofs << "      </PointData>\n";
  ofs << "      <CellData>\n" << cellData << std::endl;
  ofs << "      </CellData>\n";
  ofs << "      <Points>\n";
  if(getSpaceDimension()==3)
    _coords->writeVTK(ofs,8,"Points");
  else
    {
      MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coo=_coords->changeNbOfComponents(3,0.);
      coo->writeVTK(ofs,8,"Points");
    }
  ofs << "      </Points>\n";
  ofs << "      <Cells>\n";
  const int *cPtr=_nodal_connec->getConstPointer();
  const int *cIPtr=_nodal_connec_index->getConstPointer();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> faceoffsets=DataArrayInt::New(); faceoffsets->alloc(nbOfCells,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> types=DataArrayInt::New(); types->alloc(nbOfCells,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> offsets=DataArrayInt::New(); offsets->alloc(nbOfCells,1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> connectivity=DataArrayInt::New(); connectivity->alloc(_nodal_connec->getNumberOfTuples()-nbOfCells,1);
  int *w1=faceoffsets->getPointer(),*w2=types->getPointer(),*w3=offsets->getPointer(),*w4=connectivity->getPointer();
  int szFaceOffsets=0,szConn=0;
  for(int i=0;i<nbOfCells;i++,w1++,w2++,w3++)
    {
      *w2=cPtr[cIPtr[i]];
      if((INTERP_KERNEL::NormalizedCellType)cPtr[cIPtr[i]]!=INTERP_KERNEL::NORM_POLYHED)
        {
          *w1=-1;
          *w3=szConn+cIPtr[i+1]-cIPtr[i]-1; szConn+=cIPtr[i+1]-cIPtr[i]-1;
          w4=std::copy(cPtr+cIPtr[i]+1,cPtr+cIPtr[i+1],w4);
        }
      else
        {
          int deltaFaceOffset=cIPtr[i+1]-cIPtr[i]+1;
          *w1=szFaceOffsets+deltaFaceOffset; szFaceOffsets+=deltaFaceOffset;
          std::set<int> c(cPtr+cIPtr[i]+1,cPtr+cIPtr[i+1]); c.erase(-1);
          *w3=szConn+(int)c.size(); szConn+=(int)c.size();
          w4=std::copy(c.begin(),c.end(),w4);
        }
    }
  types->transformWithIndArr(PARAMEDMEM2VTKTYPETRADUCER,PARAMEDMEM2VTKTYPETRADUCER+INTERP_KERNEL::NORM_MAXTYPE);
  types->writeVTK(ofs,8,"UInt8","types");
  offsets->writeVTK(ofs,8,"Int32","offsets");
  if(szFaceOffsets!=0)
    {//presence of Polyhedra
      connectivity->reAlloc(szConn);
      faceoffsets->writeVTK(ofs,8,"Int32","faceoffsets");
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> faces=DataArrayInt::New(); faces->alloc(szFaceOffsets,1);
      w1=faces->getPointer();
      for(int i=0;i<nbOfCells;i++)
        if((INTERP_KERNEL::NormalizedCellType)cPtr[cIPtr[i]]==INTERP_KERNEL::NORM_POLYHED)
          {
            int nbFaces=std::count(cPtr+cIPtr[i]+1,cPtr+cIPtr[i+1],-1)+1;
            *w1++=nbFaces;
            const int *w6=cPtr+cIPtr[i]+1,*w5=0;
            for(int j=0;j<nbFaces;j++)
              {
                w5=std::find(w6,cPtr+cIPtr[i+1],-1);
                *w1++=(int)std::distance(w6,w5);
                w1=std::copy(w6,w5,w1);
                w6=w5+1;
              }
          }
      faces->writeVTK(ofs,8,"Int32","faces");
    }
  connectivity->writeVTK(ofs,8,"Int32","connectivity");
  ofs << "      </Cells>\n";
  ofs << "    </Piece>\n";
  ofs << "  </" << getVTKDataSetType() << ">\n";
}

std::string MEDCouplingUMesh::getVTKDataSetType() const throw(INTERP_KERNEL::Exception)
{
  return std::string("UnstructuredGrid");
}

/// @cond INTERNAL

MEDCouplingUMesh *MEDCouplingUMesh::Intersect2DMeshes(const MEDCouplingUMesh *m1, const MEDCouplingUMesh *m2, double eps, DataArrayInt *&cellNb1, DataArrayInt *&cellNb2) throw(INTERP_KERNEL::Exception)
{
  m1->checkFullyDefined();
  m2->checkFullyDefined();
  if(m1->getMeshDimension()!=2 || m1->getSpaceDimension()!=2 || m2->getMeshDimension()!=2 || m2->getSpaceDimension()!=2)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::Intersect2DMeshes works on umeshes m1 AND m2  with meshdim equal to 2 and spaceDim equal to 2 too!");
  std::vector< std::vector<int> > intersectEdge1, colinear2, subDiv2;
  MEDCouplingUMesh *m1Desc=0,*m2Desc=0;
  DataArrayInt *desc1=0,*descIndx1=0,*revDesc1=0,*revDescIndx1=0,*desc2=0,*descIndx2=0,*revDesc2=0,*revDescIndx2=0;
  std::vector<double> addCoo,addCoordsQuadratic;
  INTERP_KERNEL::QUADRATIC_PLANAR::_precision=eps;
  INTERP_KERNEL::QUADRATIC_PLANAR::_arc_detection_precision=eps;
  IntersectDescending2DMeshes(m1,m2,eps,intersectEdge1,colinear2, subDiv2,m1Desc,desc1,descIndx1,revDesc1,revDescIndx1,
                              m2Desc,desc2,descIndx2,revDesc2,revDescIndx2,addCoo);
  revDesc1->decrRef(); revDescIndx1->decrRef(); revDesc2->decrRef(); revDescIndx2->decrRef();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> dd1(desc1),dd2(descIndx1),dd3(desc2),dd4(descIndx2);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> dd5(m1Desc),dd6(m2Desc);
  std::vector< std::vector<int> > intersectEdge2;
  BuildIntersectEdges(m1Desc,m2Desc,addCoo,subDiv2,intersectEdge2);
  subDiv2.clear(); dd5=0; dd6=0;
  std::vector<int> cr,crI; //no DataArrayInt because interface with Geometric2D
  std::vector<int> cNb1,cNb2; //no DataArrayInt because interface with Geometric2D
  BuildIntersecting2DCellsFromEdges(eps,m1,desc1->getConstPointer(),descIndx1->getConstPointer(),intersectEdge1,colinear2,m2,desc2->getConstPointer(),descIndx2->getConstPointer(),intersectEdge2,addCoo,
                                    /* outputs -> */addCoordsQuadratic,cr,crI,cNb1,cNb2);
  //
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> addCooDa=DataArrayDouble::New();
  addCooDa->alloc((int)(addCoo.size())/2,2);
  std::copy(addCoo.begin(),addCoo.end(),addCooDa->getPointer());
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> addCoordsQuadraticDa=DataArrayDouble::New();
  addCoordsQuadraticDa->alloc((int)(addCoordsQuadratic.size())/2,2);
  std::copy(addCoordsQuadratic.begin(),addCoordsQuadratic.end(),addCoordsQuadraticDa->getPointer());
  std::vector<const DataArrayDouble *> coordss(4);
  coordss[0]=m1->getCoords(); coordss[1]=m2->getCoords(); coordss[2]=addCooDa; coordss[3]=addCoordsQuadraticDa;
  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coo=DataArrayDouble::Aggregate(coordss);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New("Intersect2D",2);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn=DataArrayInt::New(); conn->alloc((int)cr.size(),1); std::copy(cr.begin(),cr.end(),conn->getPointer());
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> connI=DataArrayInt::New(); connI->alloc((int)crI.size(),1); std::copy(crI.begin(),crI.end(),connI->getPointer());
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> c1=DataArrayInt::New(); c1->alloc((int)cNb1.size(),1); std::copy(cNb1.begin(),cNb1.end(),c1->getPointer());
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> c2=DataArrayInt::New(); c2->alloc((int)cNb2.size(),1); std::copy(cNb2.begin(),cNb2.end(),c2->getPointer());
  ret->setConnectivity(conn,connI,true);
  ret->setCoords(coo);
  cellNb1=c1.retn(); cellNb2=c2.retn();
  return ret.retn();
}

/// @endcond

void MEDCouplingUMesh::BuildIntersecting2DCellsFromEdges(double eps, const MEDCouplingUMesh *m1, const int *desc1, const int *descIndx1,
                                                         const std::vector<std::vector<int> >& intesctEdges1, const std::vector< std::vector<int> >& colinear2,
                                                         const MEDCouplingUMesh *m2, const int *desc2, const int *descIndx2, const std::vector<std::vector<int> >& intesctEdges2,
                                                         const std::vector<double>& addCoords,
                                                         std::vector<double>& addCoordsQuadratic, std::vector<int>& cr, std::vector<int>& crI, std::vector<int>& cNb1, std::vector<int>& cNb2)
{
  static const int SPACEDIM=2;
  std::vector<double> bbox1,bbox2;
  const double *coo1=m1->getCoords()->getConstPointer();
  const int *conn1=m1->getNodalConnectivity()->getConstPointer();
  const int *connI1=m1->getNodalConnectivityIndex()->getConstPointer();
  int offset1=m1->getNumberOfNodes();
  const double *coo2=m2->getCoords()->getConstPointer();
  const int *conn2=m2->getNodalConnectivity()->getConstPointer();
  const int *connI2=m2->getNodalConnectivityIndex()->getConstPointer();
  int offset2=offset1+m2->getNumberOfNodes();
  int offset3=offset2+((int)addCoords.size())/2;
  m1->getBoundingBoxForBBTree(bbox1);
  m2->getBoundingBoxForBBTree(bbox2);
  BBTree<SPACEDIM,int> myTree(&bbox2[0],0,0,m2->getNumberOfCells(),eps);
  int ncell1=m1->getNumberOfCells();
  crI.push_back(0);
  for(int i=0;i<ncell1;i++)
    {
      std::vector<int> candidates2;
      myTree.getIntersectingElems(&bbox1[i*2*SPACEDIM],candidates2);
      std::map<INTERP_KERNEL::Node *,int> mapp;
      std::map<int,INTERP_KERNEL::Node *> mappRev;
      INTERP_KERNEL::QuadraticPolygon pol1;
      INTERP_KERNEL::NormalizedCellType typ=(INTERP_KERNEL::NormalizedCellType)conn1[connI1[i]];
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(typ);
      MEDCouplingUMeshBuildQPFromMesh3(coo1,offset1,coo2,offset2,addCoords,desc1+descIndx1[i],desc1+descIndx1[i+1],intesctEdges1,/* output */mapp,mappRev);
      pol1.buildFromCrudeDataArray(mappRev,cm.isQuadratic(),conn1+connI1[i]+1,coo1,
                                   desc1+descIndx1[i],desc1+descIndx1[i+1],intesctEdges1);
      //
      std::set<INTERP_KERNEL::Edge *> edges1;// store all edges of pol1 that are NOT consumed by intersect cells. If any after iteration over candidates2 -> a part of pol1 should appear in result
      std::set<INTERP_KERNEL::Edge *> edgesBoundary2;// store all edges that are on boundary of (pol2 intersect pol1) minus edges on pol1.
      INTERP_KERNEL::IteratorOnComposedEdge it1(&pol1);
      for(it1.first();!it1.finished();it1.next())
        edges1.insert(it1.current()->getPtr());
      //
      std::map<int,std::vector<INTERP_KERNEL::ElementaryEdge *> > edgesIn2ForShare;
      std::vector<INTERP_KERNEL::QuadraticPolygon> pol2s(candidates2.size());
      int ii=0;
      for(std::vector<int>::const_iterator it2=candidates2.begin();it2!=candidates2.end();it2++,ii++)
        {
          INTERP_KERNEL::NormalizedCellType typ2=(INTERP_KERNEL::NormalizedCellType)conn2[connI2[*it2]];
          const INTERP_KERNEL::CellModel& cm2=INTERP_KERNEL::CellModel::GetCellModel(typ2);
          MEDCouplingUMeshBuildQPFromMesh3(coo1,offset1,coo2,offset2,addCoords,desc2+descIndx2[*it2],desc2+descIndx2[*it2+1],intesctEdges2,/* output */mapp,mappRev);
          pol2s[ii].buildFromCrudeDataArray2(mappRev,cm2.isQuadratic(),conn2+connI2[*it2]+1,coo2,desc2+descIndx2[*it2],desc2+descIndx2[*it2+1],intesctEdges2,
                                             pol1,desc1+descIndx1[i],desc1+descIndx1[i+1],intesctEdges1,colinear2,edgesIn2ForShare);
        }
      ii=0;
      for(std::vector<int>::const_iterator it2=candidates2.begin();it2!=candidates2.end();it2++,ii++)
        {
          pol1.initLocationsWithOther(pol2s[ii]);
          pol2s[ii].updateLocOfEdgeFromCrudeDataArray2(desc2+descIndx2[*it2],desc2+descIndx2[*it2+1],intesctEdges2,pol1,desc1+descIndx1[i],desc1+descIndx1[i+1],intesctEdges1,colinear2);
          //MEDCouplingUMeshAssignOnLoc(pol1,pol2,desc1+descIndx1[i],desc1+descIndx1[i+1],intesctEdges1,desc2+descIndx2[*it2],desc2+descIndx2[*it2+1],intesctEdges2,colinear2);
          pol1.buildPartitionsAbs(pol2s[ii],edges1,edgesBoundary2,mapp,i,*it2,offset3,addCoordsQuadratic,cr,crI,cNb1,cNb2);
        }
      if(!edges1.empty())
        {
          try
            {
              INTERP_KERNEL::QuadraticPolygon::ComputeResidual(pol1,edges1,edgesBoundary2,mapp,offset3,i,addCoordsQuadratic,cr,crI,cNb1,cNb2);
            }
          catch(INTERP_KERNEL::Exception& e)
            {
              std::ostringstream oss; oss << "Error when computing residual of cell #" << i << " in source/m1 mesh ! Maybe the neighbours of this cell in mesh are not well connected !\n" << "The deep reason is the following : " << e.what();
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
      for(std::map<int,INTERP_KERNEL::Node *>::const_iterator it=mappRev.begin();it!=mappRev.end();it++)
        (*it).second->decrRef();
    }
}

/*!
 * This method is private and is the first step of Partition of 2D mesh (spaceDim==2 and meshDim==2).
 * 
 */
void MEDCouplingUMesh::IntersectDescending2DMeshes(const MEDCouplingUMesh *m1, const MEDCouplingUMesh *m2, double eps,
                                                   std::vector< std::vector<int> >& intersectEdge1, std::vector< std::vector<int> >& colinear2, std::vector< std::vector<int> >& subDiv2,
                                                   MEDCouplingUMesh *& m1Desc, DataArrayInt *&desc1, DataArrayInt *&descIndx1, DataArrayInt *&revDesc1, DataArrayInt *&revDescIndx1,
                                                   MEDCouplingUMesh *& m2Desc, DataArrayInt *&desc2, DataArrayInt *&descIndx2, DataArrayInt *&revDesc2, DataArrayInt *&revDescIndx2,
                                                   std::vector<double>& addCoo) throw(INTERP_KERNEL::Exception)
{
  static const int SPACEDIM=2;
  desc1=DataArrayInt::New(); descIndx1=DataArrayInt::New(); revDesc1=DataArrayInt::New(); revDescIndx1=DataArrayInt::New();
  desc2=DataArrayInt::New();
  descIndx2=DataArrayInt::New();
  revDesc2=DataArrayInt::New();
  revDescIndx2=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> dd1(desc1),dd2(descIndx1),dd3(revDesc1),dd4(revDescIndx1);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> dd5(desc2),dd6(descIndx2),dd7(revDesc2),dd8(revDescIndx2);
  m1Desc=m1->buildDescendingConnectivity2(desc1,descIndx1,revDesc1,revDescIndx1);
  m2Desc=m2->buildDescendingConnectivity2(desc2,descIndx2,revDesc2,revDescIndx2);
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> dd9(m1Desc),dd10(m2Desc);
  const int *c1=m1Desc->getNodalConnectivity()->getConstPointer();
  const int *ci1=m1Desc->getNodalConnectivityIndex()->getConstPointer();
  std::vector<double> bbox1,bbox2;
  m1Desc->getBoundingBoxForBBTree(bbox1);
  m2Desc->getBoundingBoxForBBTree(bbox2);
  int ncell1=m1Desc->getNumberOfCells();
  int ncell2=m2Desc->getNumberOfCells();
  intersectEdge1.resize(ncell1);
  colinear2.resize(ncell2);
  subDiv2.resize(ncell2);
  BBTree<SPACEDIM,int> myTree(&bbox2[0],0,0,m2Desc->getNumberOfCells(),-eps);
  std::vector<int> candidates1(1);
  int offset1=m1->getNumberOfNodes();
  int offset2=offset1+m2->getNumberOfNodes();
  for(int i=0;i<ncell1;i++)
    {
      std::vector<int> candidates2;
      myTree.getIntersectingElems(&bbox1[i*2*SPACEDIM],candidates2);
      if(!candidates2.empty())
        {
          std::map<INTERP_KERNEL::Node *,int> map1,map2;
          INTERP_KERNEL::QuadraticPolygon *pol2=MEDCouplingUMeshBuildQPFromMesh(m2Desc,candidates2,map2);
          candidates1[0]=i;
          INTERP_KERNEL::QuadraticPolygon *pol1=MEDCouplingUMeshBuildQPFromMesh(m1Desc,candidates1,map1);
          pol1->splitAbs(*pol2,map1,map2,offset1,offset2,candidates2,intersectEdge1[i],i,colinear2,subDiv2,addCoo);
          delete pol2;
          delete pol1;
        }
      else
        intersectEdge1[i].insert(intersectEdge1[i].end(),c1+ci1[i]+1,c1+ci1[i+1]);
    }
  m1Desc->incrRef(); desc1->incrRef(); descIndx1->incrRef(); revDesc1->incrRef(); revDescIndx1->incrRef();
  m2Desc->incrRef(); desc2->incrRef(); descIndx2->incrRef(); revDesc2->incrRef(); revDescIndx2->incrRef();
}

/*!
 * This method performs the 2nd step of Partition of 2D mesh.
 * This method has 4 inputs :
 *  - a mesh 'm1' with meshDim==1 and a SpaceDim==2
 *  - a mesh 'm2' with meshDim==1 and a SpaceDim==2
 *  - subDiv of size 'm2->getNumberOfCells()' that lists for each seg cell in 'm' the splitting node ids in randomly sorted.
 * The aim of this method is to sort the splitting nodes, if any, and to put in 'intersectEdge' output paramter based on edges of mesh 'm2'
 * @param m1 is expected to be a mesh of meshDimension equal to 1 and spaceDim equal to 2. No check of that is performed by this method. Only present for its coords in case of 'subDiv' shares some nodes of 'm1'
 * @param m2 is expected to be a mesh of meshDimension equal to 1 and spaceDim equal to 2. No check of that is performed by this method.
 * @param addCoo input parameter with additionnal nodes linked to intersection of the 2 meshes.
 */
void MEDCouplingUMesh::BuildIntersectEdges(const MEDCouplingUMesh *m1, const MEDCouplingUMesh *m2, const std::vector<double>& addCoo, const std::vector< std::vector<int> >& subDiv, std::vector< std::vector<int> >& intersectEdge) throw(INTERP_KERNEL::Exception)
{
  int offset1=m1->getNumberOfNodes();
  int ncell=m2->getNumberOfCells();
  const int *c=m2->getNodalConnectivity()->getConstPointer();
  const int *cI=m2->getNodalConnectivityIndex()->getConstPointer();
  const double *coo=m2->getCoords()->getConstPointer();
  const double *cooBis=m1->getCoords()->getConstPointer();
  int offset2=offset1+m2->getNumberOfNodes();
  intersectEdge.resize(ncell);
  for(int i=0;i<ncell;i++,cI++)
    {
      const std::vector<int>& divs=subDiv[i];
      int nnode=cI[1]-cI[0]-1;
      std::map<int, std::pair<INTERP_KERNEL::Node *,bool> > mapp2;
      std::map<INTERP_KERNEL::Node *, int> mapp22;
      for(int j=0;j<nnode;j++)
        {
          INTERP_KERNEL::Node *nn=new INTERP_KERNEL::Node(coo[2*c[(*cI)+j+1]],coo[2*c[(*cI)+j+1]+1]);
          int nnid=c[(*cI)+j+1];
          mapp2[nnid]=std::pair<INTERP_KERNEL::Node *,bool>(nn,true);
          mapp22[nn]=nnid+offset1;
        }
      INTERP_KERNEL::Edge *e=MEDCouplingUMeshBuildQPFromEdge((INTERP_KERNEL::NormalizedCellType)c[*cI],mapp2,c+(*cI)+1);
      for(std::map<int, std::pair<INTERP_KERNEL::Node *,bool> >::const_iterator it=mapp2.begin();it!=mapp2.end();it++)
        ((*it).second.first)->decrRef();
      std::vector<INTERP_KERNEL::Node *> addNodes(divs.size());
      std::map<INTERP_KERNEL::Node *,int> mapp3;
      for(std::size_t j=0;j<divs.size();j++)
        {
          int id=divs[j];
          INTERP_KERNEL::Node *tmp=0;
          if(id<offset1)
            tmp=new INTERP_KERNEL::Node(cooBis[2*id],cooBis[2*id+1]);
          else if(id<offset2)
            tmp=new INTERP_KERNEL::Node(coo[2*(id-offset1)],coo[2*(id-offset1)+1]);//if it happens, bad news mesh 'm2' is non conform.
          else
            tmp=new INTERP_KERNEL::Node(addCoo[2*(id-offset2)],addCoo[2*(id-offset2)+1]);
          addNodes[j]=tmp;
          mapp3[tmp]=id;
        }
      e->sortIdsAbs(addNodes,mapp22,mapp3,intersectEdge[i]);
      for(std::vector<INTERP_KERNEL::Node *>::const_iterator it=addNodes.begin();it!=addNodes.end();it++)
        (*it)->decrRef();
      e->decrRef();
    }
}

/*!
 * This method is part of the Slice3D algorithm. It is the first step of assembly process, ones coordinates have been computed (by MEDCouplingUMesh::split3DCurveWithPlane method).
 * This method allows to compute given the status of 3D curve cells and the descending connectivity 3DSurf->3DCurve to deduce the intersection of each 3D surf cells
 * with a plane. The result will be put in 'cut3DSuf' out parameter.
 * @param cut3DCurve  input paramter that gives for each 3DCurve cell if it owns fully to the plane or partially.
 * @param nodesOnPlane, returns all the nodes that are on the plane.
 * @param nodal3DSurf is the nodal connectivity of 3D surf mesh.
 * @param nodalIndx3DSurf is the nodal connectivity index of 3D surf mesh.
 * @param nodal3DCurve is the nodal connectivity of 3D curve mesh.
 * @param nodal3DIndxCurve is the nodal connectivity index of 3D curve mesh.
 * @param desc is the descending connectivity 3DSurf->3DCurve
 * @param descIndx is the descending connectivity index 3DSurf->3DCurve
 * @param cut3DSuf input/output param.
 */
void MEDCouplingUMesh::AssemblyForSplitFrom3DCurve(const std::vector<int>& cut3DCurve, std::vector<int>& nodesOnPlane, const int *nodal3DSurf, const int *nodalIndx3DSurf,
                                                   const int *nodal3DCurve, const int *nodalIndx3DCurve,
                                                   const int *desc, const int *descIndx, 
                                                   std::vector< std::pair<int,int> >& cut3DSurf) throw(INTERP_KERNEL::Exception)
{
  std::set<int> nodesOnP(nodesOnPlane.begin(),nodesOnPlane.end());
  int nbOf3DSurfCell=(int)cut3DSurf.size();
  for(int i=0;i<nbOf3DSurfCell;i++)
    {
      std::vector<int> res;
      int offset=descIndx[i];
      int nbOfSeg=descIndx[i+1]-offset;
      for(int j=0;j<nbOfSeg;j++)
        {
          int edgeId=desc[offset+j];
          int status=cut3DCurve[edgeId];
          if(status!=-2)
            {
              if(status>-1)
                res.push_back(status);
              else
                {
                  res.push_back(nodal3DCurve[nodalIndx3DCurve[edgeId]+1]);
                  res.push_back(nodal3DCurve[nodalIndx3DCurve[edgeId]+2]);
                }
            }
        }
      switch(res.size())
        {
        case 2:
          {
            cut3DSurf[i].first=res[0]; cut3DSurf[i].second=res[1];
            break;
          }
        case 1:
        case 0:
          {
            std::set<int> s1(nodal3DSurf+nodalIndx3DSurf[i]+1,nodal3DSurf+nodalIndx3DSurf[i+1]);
            std::set_intersection(nodesOnP.begin(),nodesOnP.end(),s1.begin(),s1.end(),std::back_insert_iterator< std::vector<int> >(res));
            if(res.size()==2)
              {
                cut3DSurf[i].first=res[0]; cut3DSurf[i].second=res[1];
              }
            else
              {
                cut3DSurf[i].first=-1; cut3DSurf[i].second=-1;
              }
            break;
          }
        default:
          {// case when plane is on a multi colinear edge of a polyhedron
            if((int)res.size()==2*nbOfSeg)
              {
                cut3DSurf[i].first=-2; cut3DSurf[i].second=i;
              }
            else
              throw INTERP_KERNEL::Exception("MEDCouplingUMesh::AssemblyPointsFrom3DCurve : unexpected situation !");
          }
        }
    }
}

/*!
 * 'this' is expected to be a mesh with spaceDim==3 and meshDim==3. If not an exception will be thrown.
 * This method is part of the Slice3D algorithm. It is the second step of assembly process, ones coordinates have been computed (by MEDCouplingUMesh::split3DCurveWithPlane method).
 * This method allows to compute given the result of 3D surf cells with plane and the descending connectivity 3D->3DSurf to deduce the intersection of each 3D cells
 * with a plane. The result will be put in 'nodalRes' 'nodalResIndx' and 'cellIds' out parameters.
 * @param cut3DSurf  input paramter that gives for each 3DSurf its intersection with plane (result of MEDCouplingUMesh::AssemblyForSplitFrom3DCurve).
 * @param desc is the descending connectivity 3D->3DSurf
 * @param descIndx is the descending connectivity index 3D->3DSurf
 */
void MEDCouplingUMesh::assemblyForSplitFrom3DSurf(const std::vector< std::pair<int,int> >& cut3DSurf,
                                                  const int *desc, const int *descIndx,
                                                  DataArrayInt *nodalRes, DataArrayInt *nodalResIndx, DataArrayInt *cellIds) const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  if(getMeshDimension()!=3 || getSpaceDimension()!=3)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::assemblyForSplitFrom3DSurf works on umeshes with meshdim equal to 3 and spaceDim equal to 3 too!");
  const int *nodal3D=_nodal_connec->getConstPointer();
  const int *nodalIndx3D=_nodal_connec_index->getConstPointer();
  int nbOfCells=getNumberOfCells();
  for(int i=0;i<nbOfCells;i++)
    {
      std::map<int, std::set<int> > m;
      int offset=descIndx[i];
      int nbOfFaces=descIndx[i+1]-offset;
      int start=-1;
      int end=-1;
      for(int j=0;j<nbOfFaces;j++)
        {
          const std::pair<int,int>& p=cut3DSurf[desc[offset+j]];
          if(p.first!=-1 && p.second!=-1)
            {
              if(p.first!=-2)
                {
                  start=p.first; end=p.second;
                  m[p.first].insert(p.second);
                  m[p.second].insert(p.first);
                }
              else
                {
                  const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)nodal3D[nodalIndx3D[i]]);
                  int sz=nodalIndx3D[i+1]-nodalIndx3D[i]-1;
                  INTERP_KERNEL::AutoPtr<int> tmp=new int[sz];
                  INTERP_KERNEL::NormalizedCellType cmsId;
                  unsigned nbOfNodesSon=cm.fillSonCellNodalConnectivity2(j,nodal3D+nodalIndx3D[i]+1,sz,tmp,cmsId);
                  start=tmp[0]; end=tmp[nbOfNodesSon-1];
                  for(unsigned k=0;k<nbOfNodesSon;k++)
                    {
                      m[tmp[k]].insert(tmp[(k+1)%nbOfNodesSon]);
                      m[tmp[(k+1)%nbOfNodesSon]].insert(tmp[k]);
                    }
                }
            }
        }
      if(m.empty())
        continue;
      std::vector<int> conn(1,(int)INTERP_KERNEL::NORM_POLYGON);
      int prev=end;
      while(end!=start)
        {
          std::map<int, std::set<int> >::const_iterator it=m.find(start);
          const std::set<int>& s=(*it).second;
          std::set<int> s2; s2.insert(prev);
          std::set<int> s3;
          std::set_difference(s.begin(),s.end(),s2.begin(),s2.end(),inserter(s3,s3.begin()));
          if(s3.size()==1)
            {
              int val=*s3.begin();
              conn.push_back(start);
              prev=start;
              start=val;
            }
          else
            start=end;
        }
      conn.push_back(end);
      if(conn.size()>3)
        {
          nodalRes->insertAtTheEnd(conn.begin(),conn.end());
          nodalResIndx->pushBackSilent(nodalRes->getNumberOfTuples());
          cellIds->pushBackSilent(i);
        }
    }
}

/*!
 * This method compute the convex hull of a single 2D cell. This method tries to conserve at maximum the given input connectivity. In particular, if the orientation of cell is not clockwise
 * as in MED format norm. If definitely the result of Jarvis algorithm is not matchable with the input connectivity, the result will be copied into \b nodalConnecOut parameter and
 * the geometric cell type set to INTERP_KERNEL::NORM_POLYGON.
 * This method excepts that \b coords parameter is expected to be in dimension 2. [\b nodalConnBg, \b nodalConnEnd) is the nodal connectivity of the input
 * cell (geometric cell type included at the position 0). If the meshdimension of the input cell is not equal to 2 an INTERP_KERNEL::Exception will be thrown.
 * 
 * @return false if the input connectivity represents already the convex hull, true if the input cell needs to be reordered.
 */
bool MEDCouplingUMesh::BuildConvexEnvelopOf2DCellJarvis(const double *coords, const int *nodalConnBg, const int *nodalConnEnd, DataArrayInt *nodalConnecOut) throw(INTERP_KERNEL::Exception)
{
  std::size_t sz=std::distance(nodalConnBg,nodalConnEnd);
  if(sz>=4)
    {
      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)*nodalConnBg);
      if(cm.getDimension()==2)
        {
          const int *node=nodalConnBg+1;
          int startNode=*node++;
          double refX=coords[2*startNode];
          for(;node!=nodalConnEnd;node++)
            {
              if(coords[2*(*node)]<refX)
                {
                  startNode=*node;
                  refX=coords[2*startNode];
                }
            }
          std::vector<int> tmpOut; tmpOut.reserve(sz); tmpOut.push_back(startNode);
          refX=1e300;
          double tmp1;
          double tmp2[2];
          double angle0=-M_PI/2;
          //
          int nextNode=-1;
          int prevNode=-1;
          double resRef;
          double angleNext;
          while(nextNode!=startNode)
            {
              nextNode=-1;
              resRef=1e300;
              for(node=nodalConnBg+1;node!=nodalConnEnd;node++)
                {
                  if(*node!=tmpOut.back() && *node!=prevNode)
                    {
                      tmp2[0]=coords[2*(*node)]-coords[2*tmpOut.back()]; tmp2[1]=coords[2*(*node)+1]-coords[2*tmpOut.back()+1];
                      double angleM=INTERP_KERNEL::EdgeArcCircle::GetAbsoluteAngle(tmp2,tmp1);
                      double res;
                      if(angleM<=angle0)
                        res=angle0-angleM;
                      else
                        res=angle0-angleM+2.*M_PI;
                      if(res<resRef)
                        {
                          nextNode=*node;
                          resRef=res;
                          angleNext=angleM;
                        }
                    }
                }
              if(nextNode!=startNode)
                {
                  angle0=angleNext-M_PI;
                  if(angle0<-M_PI)
                    angle0+=2*M_PI;
                  prevNode=tmpOut.back();
                  tmpOut.push_back(nextNode);
                }
            }
          std::vector<int> tmp3(2*(sz-1));
          std::vector<int>::iterator it=std::copy(nodalConnBg+1,nodalConnEnd,tmp3.begin());
          std::copy(nodalConnBg+1,nodalConnEnd,it);
          if(std::search(tmp3.begin(),tmp3.end(),tmpOut.begin(),tmpOut.end())!=tmp3.end())
            {
              nodalConnecOut->insertAtTheEnd(nodalConnBg,nodalConnEnd);
              return false;
            }
          if(std::search(tmp3.rbegin(),tmp3.rend(),tmpOut.begin(),tmpOut.end())!=tmp3.rend())
            {
              nodalConnecOut->insertAtTheEnd(nodalConnBg,nodalConnEnd);
              return false;
            }
          else
            {
              nodalConnecOut->pushBackSilent((int)INTERP_KERNEL::NORM_POLYGON);
              nodalConnecOut->insertAtTheEnd(tmpOut.begin(),tmpOut.end());
              return true;
            }
        }
      else
        throw INTERP_KERNEL::Exception("MEDCouplingUMesh::BuildConvexEnvelopOf2DCellJarvis : invalid 2D cell connectivity !");
    }
  else
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::BuildConvexEnvelopOf2DCellJarvis : invalid 2D cell connectivity !");
}

/*!
 * This method works on an input pair (\b arr, \b arrIndx) where \b arr indexes is in \b arrIndx.
 * This method will not impact the size of inout parameter \b arrIndx but the size of \b arr will be modified in case of suppression.
 * 
 * \param [in] idsToRemoveBg begin of set of ids to remove in \b arr (included)
 * \param [in] idsToRemoveEnd end of set of ids to remove in \b arr (excluded)
 * \param [in,out] arr array in which the remove operation will be done.
 * \param [in,out] arrIndx array in the remove operation will modify
 * \param [in] offsetForRemoval (by default 0) offset so that for each i in [0,arrIndx->getNumberOfTuples()-1) removal process will be performed in the following range [arr+arrIndx[i]+offsetForRemoval,arr+arr[i+1])
 * \return true if \b arr and \b arrIndx have been modified, false if not.
 */
bool MEDCouplingUMesh::RemoveIdsFromIndexedArrays(const int *idsToRemoveBg, const int *idsToRemoveEnd, DataArrayInt *arr, DataArrayInt *arrIndx, int offsetForRemoval) throw(INTERP_KERNEL::Exception)
{
  if(!arrIndx || !arr)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::RemoveIdsFromIndexedArrays : some input arrays are empty !");
  if(offsetForRemoval<0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::RemoveIdsFromIndexedArrays : offsetForRemoval should be >=0 !");
  std::set<int> s(idsToRemoveBg,idsToRemoveEnd);
  int nbOfGrps=arrIndx->getNumberOfTuples()-1;
  int *arrIPtr=arrIndx->getPointer();
  *arrIPtr++=0;
  int previousArrI=0;
  const int *arrPtr=arr->getConstPointer();
  std::vector<int> arrOut;//no utility to switch to DataArrayInt because copy always needed
  for(int i=0;i<nbOfGrps;i++,arrIPtr++)
    {
      if(*arrIPtr-previousArrI>offsetForRemoval)
        {
          for(const int *work=arrPtr+previousArrI+offsetForRemoval;work!=arrPtr+*arrIPtr;work++)
            {
              if(s.find(*work)==s.end())
                arrOut.push_back(*work);
            }
        }
      previousArrI=*arrIPtr;
      *arrIPtr=(int)arrOut.size();
    }
  if(arr->getNumberOfTuples()==(int)arrOut.size())
    return false;
  arr->alloc((int)arrOut.size(),1);
  std::copy(arrOut.begin(),arrOut.end(),arr->getPointer());
  return true;
}

/*!
 * This method works on a pair input (\b arrIn, \b arrIndxIn) where \b arrIn indexes is in \b arrIndxIn.
 * This method returns the result of the extraction ( specified by a set of ids in [\b idsOfSelectBg , \b idsOfSelectEnd ) ).
 * The selection of extraction is done standardly in new2old format.
 * This method returns indexed arrays using 2 arrays (arrOut,arrIndexOut).
 *
 * \param [in] idsOfSelectBg begin of set of ids of the input extraction (included)
 * \param [in] idsOfSelectEnd end of set of ids of the input extraction (excluded)
 * \param [in] arrIn arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \param [out] arrOut the resulting array
 * \param [out] arrIndexOut the index array of the resulting array \b arrOut
 */
void MEDCouplingUMesh::ExtractFromIndexedArrays(const int *idsOfSelectBg, const int *idsOfSelectEnd, const DataArrayInt *arrIn, const DataArrayInt *arrIndxIn,
                                                DataArrayInt* &arrOut, DataArrayInt* &arrIndexOut) throw(INTERP_KERNEL::Exception)
{
  if(!arrIn || !arrIndxIn)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::ExtractFromIndexedArrays : input pointer is NULL !");
  std::size_t sz=std::distance(idsOfSelectBg,idsOfSelectEnd);
  const int *arrInPtr=arrIn->getConstPointer();
  const int *arrIndxPtr=arrIndxIn->getConstPointer();
  int nbOfGrps=arrIndxIn->getNumberOfTuples()-1;
  int maxSizeOfArr=arrIn->getNumberOfTuples();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arro=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arrIo=DataArrayInt::New();
  arrIo->alloc((int)(sz+1),1);
  const int *idsIt=idsOfSelectBg;
  int *work=arrIo->getPointer();
  *work++=0;
  int lgth=0;
  for(std::size_t i=0;i<sz;i++,work++,idsIt++)
    {
      if(*idsIt>=0 && *idsIt<nbOfGrps)
        lgth+=arrIndxPtr[*idsIt+1]-arrIndxPtr[*idsIt];
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::ExtractFromIndexedArrays : id located on pos #" << i << " value is " << *idsIt << " ! Must be in [0," << nbOfGrps << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
      if(lgth>=work[-1])
        *work=lgth;
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::ExtractFromIndexedArrays : id located on pos #" << i << " value is " << *idsIt << " and at this pos arrIndxIn[" << *idsIt;
          oss << "+1]-arrIndxIn[" << *idsIt << "] < 0 ! The input index array is bugged !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  arro->alloc(lgth,1);
  work=arro->getPointer();
  idsIt=idsOfSelectBg;
  for(std::size_t i=0;i<sz;i++,idsIt++)
    {
      if(arrIndxPtr[*idsIt]>=0 && arrIndxPtr[*idsIt+1]<=maxSizeOfArr)
        work=std::copy(arrInPtr+arrIndxPtr[*idsIt],arrInPtr+arrIndxPtr[*idsIt+1],work);
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::ExtractFromIndexedArrays : id located on pos #" << i << " value is " << *idsIt << " arrIndx[" << *idsIt << "] must be >= 0 and arrIndx[";
          oss << *idsIt << "+1] <= " << maxSizeOfArr << " (the size of arrIn)!";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  arrOut=arro.retn();
  arrIndexOut=arrIo.retn();
}

/*!
 * This method works on an input pair (\b arrIn, \b arrIndxIn) where \b arrIn indexes is in \b arrIndxIn.
 * This method builds an output pair (\b arrOut,\b arrIndexOut) that is a copy from \b arrIn for all cell ids \b not \b in [\b idsOfSelectBg, \b idsOfSelectEnd) and for
 * cellIds \b in [\b idsOfSelectBg, \b idsOfSelectEnd) a copy coming from the corresponding values in input pair (\b srcArr, \b srcArrIndex).
 * This method is an generalization of MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx that performs the same thing but by without building explicitely a result output arrays.
 *
 * \param [in] idsOfSelectBg begin of set of ids of the input extraction (included)
 * \param [in] idsOfSelectEnd end of set of ids of the input extraction (excluded)
 * \param [in] arrIn arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \param [in] srcArr input array that will be used as source of copy for ids in [\b idsOfSelectBg, \b idsOfSelectEnd)
 * \param [in] srcArrIndex index array of \b srcArr
 * \param [out] arrOut the resulting array
 * \param [out] arrIndexOut the index array of the resulting array \b arrOut
 * 
 * \sa MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx
 */
void MEDCouplingUMesh::SetPartOfIndexedArrays(const int *idsOfSelectBg, const int *idsOfSelectEnd, const DataArrayInt *arrIn, const DataArrayInt *arrIndxIn,
                                              const DataArrayInt *srcArr, const DataArrayInt *srcArrIndex,
                                              DataArrayInt* &arrOut, DataArrayInt* &arrIndexOut) throw(INTERP_KERNEL::Exception)
{
  if(arrIn==0 || arrIndxIn==0 || srcArr==0 || srcArrIndex==0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::SetPartOfIndexedArrays : presence of null pointer in input parameter !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arro=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arrIo=DataArrayInt::New();
  int nbOfTuples=arrIndxIn->getNumberOfTuples()-1;
  std::vector<bool> v(nbOfTuples,true);
  int offset=0;
  const int *arrIndxInPtr=arrIndxIn->getConstPointer();
  const int *srcArrIndexPtr=srcArrIndex->getConstPointer();
  for(const int *it=idsOfSelectBg;it!=idsOfSelectEnd;it++,srcArrIndexPtr++)
    {
      if(*it>=0 && *it<nbOfTuples)
        {
          v[*it]=false;
          offset+=(srcArrIndexPtr[1]-srcArrIndexPtr[0])-(arrIndxInPtr[*it+1]-arrIndxInPtr[*it]);
        }
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::SetPartOfIndexedArrays : On pos #" << std::distance(idsOfSelectBg,it) << " value is " << *it << " not in [0," << nbOfTuples << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  srcArrIndexPtr=srcArrIndex->getConstPointer();
  arrIo->alloc(nbOfTuples+1,1);
  arro->alloc(arrIn->getNumberOfTuples()+offset,1);
  const int *arrInPtr=arrIn->getConstPointer();
  const int *srcArrPtr=srcArr->getConstPointer();
  int *arrIoPtr=arrIo->getPointer(); *arrIoPtr++=0;
  int *arroPtr=arro->getPointer();
  for(int ii=0;ii<nbOfTuples;ii++,arrIoPtr++)
    {
      if(v[ii])
        {
          arroPtr=std::copy(arrInPtr+arrIndxInPtr[ii],arrInPtr+arrIndxInPtr[ii+1],arroPtr);
          *arrIoPtr=arrIoPtr[-1]+(arrIndxInPtr[ii+1]-arrIndxInPtr[ii]);
        }
      else
        {
          std::size_t pos=std::distance(idsOfSelectBg,std::find(idsOfSelectBg,idsOfSelectEnd,ii));
          arroPtr=std::copy(srcArrPtr+srcArrIndexPtr[pos],srcArrPtr+srcArrIndexPtr[pos+1],arroPtr);
          *arrIoPtr=arrIoPtr[-1]+(srcArrIndexPtr[pos+1]-srcArrIndexPtr[pos]);
        }
    }
  arrOut=arro.retn();
  arrIndexOut=arrIo.retn();
}

/*!
 * This method works on an input pair (\b arrIn, \b arrIndxIn) where \b arrIn indexes is in \b arrIndxIn.
 * This method is an specialization of MEDCouplingUMesh::SetPartOfIndexedArrays in the case of assignement do not modify the index in \b arrIndxIn.
 *
 * \param [in] idsOfSelectBg begin of set of ids of the input extraction (included)
 * \param [in] idsOfSelectEnd end of set of ids of the input extraction (excluded)
 * \param [in,out] arrInOut arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \param [in] srcArr input array that will be used as source of copy for ids in [\b idsOfSelectBg, \b idsOfSelectEnd)
 * \param [in] srcArrIndex index array of \b srcArr
 * 
 * \sa MEDCouplingUMesh::SetPartOfIndexedArrays
 */
void MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx(const int *idsOfSelectBg, const int *idsOfSelectEnd, DataArrayInt *arrInOut, const DataArrayInt *arrIndxIn,
                                                     const DataArrayInt *srcArr, const DataArrayInt *srcArrIndex) throw(INTERP_KERNEL::Exception)
{
  if(arrInOut==0 || arrIndxIn==0 || srcArr==0 || srcArrIndex==0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx : presence of null pointer in input parameter !");
  int nbOfTuples=arrIndxIn->getNumberOfTuples()-1;
  const int *arrIndxInPtr=arrIndxIn->getConstPointer();
  const int *srcArrIndexPtr=srcArrIndex->getConstPointer();
  int *arrInOutPtr=arrInOut->getPointer();
  const int *srcArrPtr=srcArr->getConstPointer();
  for(const int *it=idsOfSelectBg;it!=idsOfSelectEnd;it++,srcArrIndexPtr++)
    {
      if(*it>=0 && *it<nbOfTuples)
        {
          if(srcArrIndexPtr[1]-srcArrIndexPtr[0]==arrIndxInPtr[*it+1]-arrIndxInPtr[*it])
            std::copy(srcArrPtr+srcArrIndexPtr[0],srcArrPtr+srcArrIndexPtr[1],arrInOutPtr+arrIndxInPtr[*it]);
          else
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx : On pos #" << std::distance(idsOfSelectBg,it) << " id (idsOfSelectBg[" << std::distance(idsOfSelectBg,it)<< "]) is " << *it << " arrIndxIn[id+1]-arrIndxIn[id]!=srcArrIndex[pos+1]-srcArrIndex[pos] !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx : On pos #" << std::distance(idsOfSelectBg,it) << " value is " << *it << " not in [0," << nbOfTuples << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
}

/*!
 * This method works on a pair input (\b arrIn, \b arrIndxIn) where \b arr indexes is in \b arrIndxIn.
 * This method expects that these two input arrays come from the output of MEDCouplingUMesh::computeNeighborsOfCells method.
 * This method start from id 0 that will be contained in output DataArrayInt. It searches then all neighbors of id0 regarding arrIn[arrIndxIn[0]:arrIndxIn[0+1]].
 * Then it is repeated recursively until either all ids are fetched or no more ids are reachable step by step.
 * A negative value in \b arrIn means that it is ignored.
 * This method is useful to see if a mesh is contiguous regarding its connectivity. If it is not the case the size of returned array is different from arrIndxIn->getNumberOfTuples()-1.
 * 
 * \param [in] arrIn arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \return a newly allocated DataArray that stores all ids fetched by the gradually spread process.
 * \sa MEDCouplingUMesh::ComputeSpreadZoneGraduallyFromSeed, MEDCouplingUMesh::partitionBySpreadZone
 */
DataArrayInt *MEDCouplingUMesh::ComputeSpreadZoneGradually(const DataArrayInt *arrIn, const DataArrayInt *arrIndxIn) throw(INTERP_KERNEL::Exception)
{
  int seed=0,nbOfDepthPeelingPerformed=0;
  return ComputeSpreadZoneGraduallyFromSeed(&seed,&seed+1,arrIn,arrIndxIn,-1,nbOfDepthPeelingPerformed);
}

/*!
 * This method works on a pair input (\b arrIn, \b arrIndxIn) where \b arr indexes is in \b arrIndxIn.
 * This method expects that these two input arrays come from the output of MEDCouplingUMesh::computeNeighborsOfCells method.
 * This method start from id 0 that will be contained in output DataArrayInt. It searches then all neighbors of id0 regarding arrIn[arrIndxIn[0]:arrIndxIn[0+1]].
 * Then it is repeated recursively until either all ids are fetched or no more ids are reachable step by step.
 * A negative value in \b arrIn means that it is ignored.
 * This method is useful to see if a mesh is contiguous regarding its connectivity. If it is not the case the size of returned array is different from arrIndxIn->getNumberOfTuples()-1.
 * \param [in] seedBg the begin pointer (included) of an array containing the seed of the search zone
 * \param [in] seedEnd the end pointer (not included) of an array containing the seed of the search zone
 * \param [in] arrIn arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \param [in] nbOfDepthPeeling the max number of peels requested in search. By default -1, that is to say, no limit.
 * \param [out] nbOfDepthPeelingPerformed the number of peels effectively performed. May be different from \a nbOfDepthPeeling
 * \return a newly allocated DataArray that stores all ids fetched by the gradually spread process.
 * \sa MEDCouplingUMesh::partitionBySpreadZone
 */
DataArrayInt *MEDCouplingUMesh::ComputeSpreadZoneGraduallyFromSeed(const int *seedBg, const int *seedEnd, const DataArrayInt *arrIn, const DataArrayInt *arrIndxIn, int nbOfDepthPeeling, int& nbOfDepthPeelingPerformed) throw(INTERP_KERNEL::Exception)
{
  nbOfDepthPeelingPerformed=0;
  if(!arrIndxIn)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::ComputeSpreadZoneGraduallyFromSeed : arrIndxIn input pointer is NULL !");
  int nbOfTuples=arrIndxIn->getNumberOfTuples()-1;
  if(nbOfTuples<=0)
    {
      DataArrayInt *ret=DataArrayInt::New(); ret->alloc(0,1);
      return ret;
    }
  //
  std::vector<bool> fetched(nbOfTuples,false);
  return ComputeSpreadZoneGraduallyFromSeedAlg(fetched,seedBg,seedEnd,arrIn,arrIndxIn,nbOfDepthPeeling,nbOfDepthPeelingPerformed);
}

DataArrayInt *MEDCouplingUMesh::ComputeSpreadZoneGraduallyFromSeedAlg(std::vector<bool>& fetched, const int *seedBg, const int *seedEnd, const DataArrayInt *arrIn, const DataArrayInt *arrIndxIn, int nbOfDepthPeeling, int& nbOfDepthPeelingPerformed) throw(INTERP_KERNEL::Exception)
{
  nbOfDepthPeelingPerformed=0;
  if(!seedBg || !seedEnd || !arrIn || !arrIndxIn)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::ComputeSpreadZoneGraduallyFromSeedAlg : some input pointer is NULL !");
  int nbOfTuples=arrIndxIn->getNumberOfTuples()-1;
  std::vector<bool> fetched2(nbOfTuples,false);
  int i=0;
  for(const int *seedElt=seedBg;seedElt!=seedEnd;seedElt++,i++)
    {
      if(*seedElt>=0 && *seedElt<nbOfTuples)
        { fetched[*seedElt]=true; fetched2[*seedElt]=true; }
      else
        { std::ostringstream oss; oss << "MEDCouplingUMesh::ComputeSpreadZoneGraduallyFromSeedAlg : At pos #" << i << " of seeds value is " << *seedElt << "! Should be in [0," << nbOfTuples << ") !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
    }
  const int *arrInPtr=arrIn->getConstPointer();
  const int *arrIndxPtr=arrIndxIn->getConstPointer();
  int targetNbOfDepthPeeling=nbOfDepthPeeling!=-1?nbOfDepthPeeling:std::numeric_limits<int>::max();
  std::vector<int> idsToFetch1(seedBg,seedEnd);
  std::vector<int> idsToFetch2;
  std::vector<int> *idsToFetch=&idsToFetch1;
  std::vector<int> *idsToFetchOther=&idsToFetch2;
  while(!idsToFetch->empty() && nbOfDepthPeelingPerformed<targetNbOfDepthPeeling)
    {
      for(std::vector<int>::const_iterator it=idsToFetch->begin();it!=idsToFetch->end();it++)
        for(const int *it2=arrInPtr+arrIndxPtr[*it];it2!=arrInPtr+arrIndxPtr[*it+1];it2++)
          if(!fetched[*it2])
            { fetched[*it2]=true; fetched2[*it2]=true; idsToFetchOther->push_back(*it2); }
      std::swap(idsToFetch,idsToFetchOther);
      idsToFetchOther->clear();
      nbOfDepthPeelingPerformed++;
    }
  int lgth=(int)std::count(fetched2.begin(),fetched2.end(),true);
  i=0;
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New(); ret->alloc(lgth,1);
  int *retPtr=ret->getPointer();
  for(std::vector<bool>::const_iterator it=fetched2.begin();it!=fetched2.end();it++,i++)
    if(*it)
      *retPtr++=i;
  return ret.retn();
}

/*!
 * This method works on an input pair (\b arrIn, \b arrIndxIn) where \b arrIn indexes is in \b arrIndxIn.
 * This method builds an output pair (\b arrOut,\b arrIndexOut) that is a copy from \b arrIn for all cell ids \b not \b in [\b idsOfSelectBg, \b idsOfSelectEnd) and for
 * cellIds \b in [\b idsOfSelectBg, \b idsOfSelectEnd) a copy coming from the corresponding values in input pair (\b srcArr, \b srcArrIndex).
 * This method is an generalization of MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx that performs the same thing but by without building explicitely a result output arrays.
 *
 * \param [in] start begin of set of ids of the input extraction (included)
 * \param [in] end end of set of ids of the input extraction (excluded)
 * \param [in] step step of the set of ids in range mode.
 * \param [in] arrIn arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \param [in] srcArr input array that will be used as source of copy for ids in [\b idsOfSelectBg, \b idsOfSelectEnd)
 * \param [in] srcArrIndex index array of \b srcArr
 * \param [out] arrOut the resulting array
 * \param [out] arrIndexOut the index array of the resulting array \b arrOut
 * 
 * \sa MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx MEDCouplingUMesh::SetPartOfIndexedArrays
 */
void MEDCouplingUMesh::SetPartOfIndexedArrays2(int start, int end, int step, const DataArrayInt *arrIn, const DataArrayInt *arrIndxIn,
                                               const DataArrayInt *srcArr, const DataArrayInt *srcArrIndex,
                                               DataArrayInt* &arrOut, DataArrayInt* &arrIndexOut) throw(INTERP_KERNEL::Exception)
{
  if(arrIn==0 || arrIndxIn==0 || srcArr==0 || srcArrIndex==0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::SetPartOfIndexedArrays2 : presence of null pointer in input parameter !");
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arro=DataArrayInt::New();
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arrIo=DataArrayInt::New();
  int nbOfTuples=arrIndxIn->getNumberOfTuples()-1;
  int offset=0;
  const int *arrIndxInPtr=arrIndxIn->getConstPointer();
  const int *srcArrIndexPtr=srcArrIndex->getConstPointer();
  int nbOfElemsToSet=DataArray::GetNumberOfItemGivenBESRelative(start,end,step,"MEDCouplingUMesh::SetPartOfIndexedArrays2 : ");
  int it=start;
  for(int i=0;i<nbOfElemsToSet;i++,srcArrIndexPtr++,it+=step)
    {
      if(it>=0 && it<nbOfTuples)
        offset+=(srcArrIndexPtr[1]-srcArrIndexPtr[0])-(arrIndxInPtr[it+1]-arrIndxInPtr[it]);
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::SetPartOfIndexedArrays2 : On pos #" << i << " value is " << it << " not in [0," << nbOfTuples << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
  srcArrIndexPtr=srcArrIndex->getConstPointer();
  arrIo->alloc(nbOfTuples+1,1);
  arro->alloc(arrIn->getNumberOfTuples()+offset,1);
  const int *arrInPtr=arrIn->getConstPointer();
  const int *srcArrPtr=srcArr->getConstPointer();
  int *arrIoPtr=arrIo->getPointer(); *arrIoPtr++=0;
  int *arroPtr=arro->getPointer();
  for(int ii=0;ii<nbOfTuples;ii++,arrIoPtr++)
    {
      int pos=DataArray::GetPosOfItemGivenBESRelativeNoThrow(ii,start,end,step);
      if(pos<0)
        {
          arroPtr=std::copy(arrInPtr+arrIndxInPtr[ii],arrInPtr+arrIndxInPtr[ii+1],arroPtr);
          *arrIoPtr=arrIoPtr[-1]+(arrIndxInPtr[ii+1]-arrIndxInPtr[ii]);
        }
      else
        {
          arroPtr=std::copy(srcArrPtr+srcArrIndexPtr[pos],srcArrPtr+srcArrIndexPtr[pos+1],arroPtr);
          *arrIoPtr=arrIoPtr[-1]+(srcArrIndexPtr[pos+1]-srcArrIndexPtr[pos]);
        }
    }
  arrOut=arro.retn();
  arrIndexOut=arrIo.retn();
}

/*!
 * This method works on an input pair (\b arrIn, \b arrIndxIn) where \b arrIn indexes is in \b arrIndxIn.
 * This method is an specialization of MEDCouplingUMesh::SetPartOfIndexedArrays in the case of assignement do not modify the index in \b arrIndxIn.
 *
 * \param [in] start begin of set of ids of the input extraction (included)
 * \param [in] end end of set of ids of the input extraction (excluded)
 * \param [in] step step of the set of ids in range mode.
 * \param [in,out] arrInOut arr origin array from which the extraction will be done.
 * \param [in] arrIndxIn is the input index array allowing to walk into \b arrIn
 * \param [in] srcArr input array that will be used as source of copy for ids in [\b idsOfSelectBg, \b idsOfSelectEnd)
 * \param [in] srcArrIndex index array of \b srcArr
 * 
 * \sa MEDCouplingUMesh::SetPartOfIndexedArrays2 MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx
 */
void MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx2(int start, int end, int step, DataArrayInt *arrInOut, const DataArrayInt *arrIndxIn,
                                                      const DataArrayInt *srcArr, const DataArrayInt *srcArrIndex) throw(INTERP_KERNEL::Exception)
{
  if(arrInOut==0 || arrIndxIn==0 || srcArr==0 || srcArrIndex==0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx2 : presence of null pointer in input parameter !");
  int nbOfTuples=arrIndxIn->getNumberOfTuples()-1;
  const int *arrIndxInPtr=arrIndxIn->getConstPointer();
  const int *srcArrIndexPtr=srcArrIndex->getConstPointer();
  int *arrInOutPtr=arrInOut->getPointer();
  const int *srcArrPtr=srcArr->getConstPointer();
  int nbOfElemsToSet=DataArray::GetNumberOfItemGivenBESRelative(start,end,step,"MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx2 : ");
  int it=start;
  for(int i=0;i<nbOfElemsToSet;i++,srcArrIndexPtr++,it+=step)
    {
      if(it>=0 && it<nbOfTuples)
        {
          if(srcArrIndexPtr[1]-srcArrIndexPtr[0]==arrIndxInPtr[it+1]-arrIndxInPtr[it])
            std::copy(srcArrPtr+srcArrIndexPtr[0],srcArrPtr+srcArrIndexPtr[1],arrInOutPtr+arrIndxInPtr[it]);
          else
            {
              std::ostringstream oss; oss << "MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx2 : On pos #" << i << " id (idsOfSelectBg[" << i << "]) is " << it << " arrIndxIn[id+1]-arrIndxIn[id]!=srcArrIndex[pos+1]-srcArrIndex[pos] !";
              throw INTERP_KERNEL::Exception(oss.str().c_str());
            }
        }
      else
        {
          std::ostringstream oss; oss << "MEDCouplingUMesh::SetPartOfIndexedArraysSameIdx2 : On pos #" << i << " value is " << it << " not in [0," << nbOfTuples << ") !";
          throw INTERP_KERNEL::Exception(oss.str().c_str());
        }
    }
}

/*!
 * \b this is expected to be a mesh fully defined whose spaceDim==meshDim.
 * It returns a new allocated mesh having the same mesh dimension and lying on same coordinates.
 * The returned mesh contains as poly cells as number of contiguous zone (regarding connectivity).
 * A spread contiguous zone is built using poly cells (polyhedra in 3D, polygons in 2D and polyline in 1D).
 * The sum of measure field of returned mesh is equal to the sum of measure field of this.
 * 
 * \return a newly allocated mesh lying on the same coords than \b this with same meshdimension than \b this.
 */
MEDCouplingUMesh *MEDCouplingUMesh::buildSpreadZonesWithPoly() const throw(INTERP_KERNEL::Exception)
{
  checkFullyDefined();
  int mdim=getMeshDimension();
  int spaceDim=getSpaceDimension();
  if(mdim!=spaceDim)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSpreadZonesWithPoly : meshdimension and spacedimension do not match !");
  std::vector<DataArrayInt *> partition=partitionBySpreadZone();
  std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> > partitionAuto; partitionAuto.reserve(partition.size());
  std::copy(partition.begin(),partition.end(),std::back_insert_iterator<std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> > >(partitionAuto));
  MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> ret=MEDCouplingUMesh::New(getName(),mdim);
  ret->setCoords(getCoords());
  ret->allocateCells((int)partition.size());
  //
  for(std::vector<DataArrayInt *>::const_iterator it=partition.begin();it!=partition.end();it++)
    {
      MEDCouplingAutoRefCountObjectPtr<MEDCouplingUMesh> tmp=static_cast<MEDCouplingUMesh *>(buildPartOfMySelf((*it)->begin(),(*it)->end(),true));
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cell;
      switch(mdim)
        {
        case 2:
          cell=tmp->buildUnionOf2DMesh();
          break;
        case 3:
          cell=tmp->buildUnionOf3DMesh();
          break;
        default:
          throw INTERP_KERNEL::Exception("MEDCouplingUMesh::buildSpreadZonesWithPoly : meshdimension supported are [2,3] ! Not implemented yet for others !");
        }
      
      ret->insertNextCell((INTERP_KERNEL::NormalizedCellType)cell->getIJSafe(0,0),cell->getNumberOfTuples()-1,cell->getConstPointer()+1);
    }
  //
  ret->finishInsertingCells();
  return ret.retn();
}

/*!
 * This method partitions \b this into contiguous zone.
 * This method only needs a well defined connectivity. Coordinates are not considered here.
 * This method returns a vector of \b newly allocated arrays that the caller has to deal with.
 */
std::vector<DataArrayInt *> MEDCouplingUMesh::partitionBySpreadZone() const throw(INTERP_KERNEL::Exception)
{
  //#if 0
  int nbOfCellsCur=getNumberOfCells();
  std::vector<DataArrayInt *> ret;
  if(nbOfCellsCur<=0)
    return ret;
  DataArrayInt *neigh=0,*neighI=0;
  computeNeighborsOfCells(neigh,neighI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> neighAuto(neigh),neighIAuto(neighI);
  std::vector<bool> fetchedCells(nbOfCellsCur,false);
  std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> > ret2;
  int seed=0;
  while(seed<nbOfCellsCur)
    {
      int nbOfPeelPerformed=0;
      ret2.push_back(ComputeSpreadZoneGraduallyFromSeedAlg(fetchedCells,&seed,&seed+1,neigh,neighI,-1,nbOfPeelPerformed));
      seed=(int)std::distance(fetchedCells.begin(),std::find(fetchedCells.begin()+seed,fetchedCells.end(),false));
    }
  for(std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> >::iterator it=ret2.begin();it!=ret2.end();it++)
    ret.push_back((*it).retn());
  return ret;
  //#endif
#if 0
  int nbOfCellsCur=getNumberOfCells();
  DataArrayInt *neigh=0,*neighI=0;
  computeNeighborsOfCells(neigh,neighI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> neighAuto(neigh),neighIAuto(neighI);
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ids=DataArrayInt::New(); ids->alloc(nbOfCellsCur,1); ids->iota();
  std::vector<DataArrayInt *> ret;
  std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayInt> > ret2;
  while(nbOfCellsCur>0)
    {
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp=MEDCouplingUMesh::ComputeSpreadZoneGradually(neighAuto,neighIAuto);
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp3=tmp->buildComplement(nbOfCellsCur);
      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp2=ids->selectByTupleId(tmp->begin(),tmp->end());
      ret2.push_back(tmp2);  ret.push_back(tmp2);
      nbOfCellsCur=tmp3->getNumberOfTuples();
      if(nbOfCellsCur>0)
        {
          ids=ids->selectByTupleId(tmp3->begin(),tmp3->end());
          MEDCouplingUMesh::ExtractFromIndexedArrays(tmp3->begin(),tmp3->end(),neighAuto,neighIAuto,neigh,neighI);
          neighAuto=neigh;
          neighIAuto=neighI;
          MEDCouplingAutoRefCountObjectPtr<DataArrayInt> renum=tmp3->invertArrayN2O2O2N(nbOfCellsCur+tmp->getNumberOfTuples());
          neighAuto->transformWithIndArr(renum->begin(),renum->end());
        }
    }
  for(std::vector<DataArrayInt *>::const_iterator it=ret.begin();it!=ret.end();it++)
    (*it)->incrRef();
  return ret;
#endif
}

/*!
 * This method returns given a distribution of cell type (returned for example by MEDCouplingUMesh::getDistributionOfTypes method and customized after) a
 * newly allocated DataArrayInt instance with 2 components ready to be interpreted as input of DataArrayInt::findRangeIdForEachTuple method.
 *
 * \param [in] code a code with the same format than those returned by MEDCouplingUMesh::getDistributionOfTypes except for the code[3*k+2] that should contain start id of chunck.
 * \return a newly allocated DataArrayInt to be managed by the caller.
 * \throw In case of \a code has not the right format (typically of size 3*n)
 */
DataArrayInt *MEDCouplingUMesh::ComputeRangesFromTypeDistribution(const std::vector<int>& code) throw(INTERP_KERNEL::Exception)
{
  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
  std::size_t nb=code.size()/3;
  if(code.size()%3!=0)
    throw INTERP_KERNEL::Exception("MEDCouplingUMesh::ComputeRangesFromTypeDistribution : invalid input code !");
  ret->alloc((int)nb,2);
  int *retPtr=ret->getPointer();
  for(std::size_t i=0;i<nb;i++,retPtr+=2)
    {
      retPtr[0]=code[3*i+2];
      retPtr[1]=code[3*i+2]+code[3*i+1];
    }
  return ret.retn();
}

MEDCouplingUMeshCellIterator::MEDCouplingUMeshCellIterator(MEDCouplingUMesh *mesh):_mesh(mesh),_cell(new MEDCouplingUMeshCell(mesh)),
                                                                                   _own_cell(true),_cell_id(-1),_nb_cell(0)
{
  if(mesh)
    {
      mesh->incrRef();
      _nb_cell=mesh->getNumberOfCells();
    }
}

MEDCouplingUMeshCellIterator::~MEDCouplingUMeshCellIterator()
{
  if(_mesh)
    _mesh->decrRef();
  if(_own_cell)
    delete _cell;
}

MEDCouplingUMeshCellIterator::MEDCouplingUMeshCellIterator(MEDCouplingUMesh *mesh, MEDCouplingUMeshCell *itc, int bg, int end):_mesh(mesh),_cell(itc),
                                                                                                                               _own_cell(false),_cell_id(bg-1),
                                                                                                                               _nb_cell(end)
{
  if(mesh)
    mesh->incrRef();
}

MEDCouplingUMeshCell *MEDCouplingUMeshCellIterator::nextt()
{
  _cell_id++;
  if(_cell_id<_nb_cell)
    {
      _cell->next();
      return _cell;
    }
  else
    return 0;
}

MEDCouplingUMeshCellByTypeEntry::MEDCouplingUMeshCellByTypeEntry(MEDCouplingUMesh *mesh):_mesh(mesh)
{
  if(_mesh)
    _mesh->incrRef();
}

MEDCouplingUMeshCellByTypeIterator *MEDCouplingUMeshCellByTypeEntry::iterator()
{
  return new MEDCouplingUMeshCellByTypeIterator(_mesh);
}

MEDCouplingUMeshCellByTypeEntry::~MEDCouplingUMeshCellByTypeEntry()
{
  if(_mesh)
    _mesh->decrRef();
}

MEDCouplingUMeshCellEntry::MEDCouplingUMeshCellEntry(MEDCouplingUMesh *mesh,  INTERP_KERNEL::NormalizedCellType type, MEDCouplingUMeshCell *itc, int bg, int end):_mesh(mesh),_type(type),
                                                                                                                                                                  _itc(itc),
                                                                                                                                                                  _bg(bg),_end(end)
{
  if(_mesh)
    _mesh->incrRef();
}

MEDCouplingUMeshCellEntry::~MEDCouplingUMeshCellEntry()
{
  if(_mesh)
    _mesh->decrRef();
}

INTERP_KERNEL::NormalizedCellType MEDCouplingUMeshCellEntry::getType() const
{
  return _type;
}

int MEDCouplingUMeshCellEntry::getNumberOfElems() const
{
  return _end-_bg;
}

MEDCouplingUMeshCellIterator *MEDCouplingUMeshCellEntry::iterator()
{
  return new MEDCouplingUMeshCellIterator(_mesh,_itc,_bg,_end);
}

MEDCouplingUMeshCellByTypeIterator::MEDCouplingUMeshCellByTypeIterator(MEDCouplingUMesh *mesh):_mesh(mesh),_cell(new MEDCouplingUMeshCell(mesh)),_cell_id(0),_nb_cell(0)
{
  if(mesh)
    {
      mesh->incrRef();
      _nb_cell=mesh->getNumberOfCells();
    }
}

MEDCouplingUMeshCellByTypeIterator::~MEDCouplingUMeshCellByTypeIterator()
{
  if(_mesh)
    _mesh->decrRef();
  delete _cell;
}

MEDCouplingUMeshCellEntry *MEDCouplingUMeshCellByTypeIterator::nextt()
{
  const int *c=_mesh->getNodalConnectivity()->getConstPointer();
  const int *ci=_mesh->getNodalConnectivityIndex()->getConstPointer();
  if(_cell_id<_nb_cell)
    {
      INTERP_KERNEL::NormalizedCellType type=(INTERP_KERNEL::NormalizedCellType)c[ci[_cell_id]];
      int nbOfElems=(int)std::distance(ci+_cell_id,std::find_if(ci+_cell_id,ci+_nb_cell,ParaMEDMEMImpl::ConnReader(c,type)));
      int startId=_cell_id;
      _cell_id+=nbOfElems;
      return new MEDCouplingUMeshCellEntry(_mesh,type,_cell,startId,_cell_id);
    }
  else
    return 0;
}

MEDCouplingUMeshCell::MEDCouplingUMeshCell(MEDCouplingUMesh *mesh):_conn(0),_conn_indx(0),_conn_lgth(NOTICABLE_FIRST_VAL)
{
  if(mesh)
    {
      _conn=mesh->getNodalConnectivity()->getPointer();
      _conn_indx=mesh->getNodalConnectivityIndex()->getPointer();
    }
}

void MEDCouplingUMeshCell::next()
{
  if(_conn_lgth!=NOTICABLE_FIRST_VAL)
    {
      _conn+=_conn_lgth;
      _conn_indx++;
    }
  _conn_lgth=_conn_indx[1]-_conn_indx[0];
}

std::string MEDCouplingUMeshCell::repr() const
{
  if(_conn_lgth!=NOTICABLE_FIRST_VAL)
    {
      std::ostringstream oss; oss << "Cell Type " << INTERP_KERNEL::CellModel::GetCellModel((INTERP_KERNEL::NormalizedCellType)_conn[0]).getRepr();
      oss << " : ";
      std::copy(_conn+1,_conn+_conn_lgth,std::ostream_iterator<int>(oss," "));
      return oss.str();
    }
  else
    return std::string("MEDCouplingUMeshCell::repr : Invalid pos");
}

INTERP_KERNEL::NormalizedCellType MEDCouplingUMeshCell::getType() const
{
  if(_conn_lgth!=NOTICABLE_FIRST_VAL)
    return (INTERP_KERNEL::NormalizedCellType)_conn[0];
  else
    return INTERP_KERNEL::NORM_ERROR;
}

const int *MEDCouplingUMeshCell::getAllConn(int& lgth) const
{
  lgth=_conn_lgth;
  if(_conn_lgth!=NOTICABLE_FIRST_VAL)
    return _conn;
  else
    return 0;
}