X-Git-Url: http://git.salome-platform.org/gitweb/?a=blobdiff_plain;f=src%2FMEDCoupling%2FMEDCouplingStructuredMesh.cxx;h=20982788adddaabd6972ca53d2ba323e4a6fa468;hb=0c9d48870957c4a9f6f82fc8e2c569780a5f886b;hp=ffd9c27c6e31b8a11b22e0390e8f181e9387e9bd;hpb=97e267c35d896c3c401989a4a165087c3bebd708;p=modules%2Fmed.git

diff --git a/src/MEDCoupling/MEDCouplingStructuredMesh.cxx b/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
index ffd9c27c6..20982788a 100644
--- a/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
@@ -21,6 +21,7 @@
 #include "MEDCouplingStructuredMesh.hxx"
 #include "MEDCouplingFieldDouble.hxx"
 #include "MEDCouplingMemArray.hxx"
+#include "MEDCoupling1GTUMesh.hxx"
 #include "MEDCouplingUMesh.hxx"
 
 #include <numeric>
@@ -39,24 +40,29 @@ MEDCouplingStructuredMesh::~MEDCouplingStructuredMesh()
 {
 }
 
-std::size_t MEDCouplingStructuredMesh::getHeapMemorySize() const
+std::size_t MEDCouplingStructuredMesh::getHeapMemorySizeWithoutChildren() const
 {
-  return MEDCouplingMesh::getHeapMemorySize();
+  return MEDCouplingMesh::getHeapMemorySizeWithoutChildren();
 }
 
-void MEDCouplingStructuredMesh::copyTinyStringsFrom(const MEDCouplingMesh *other) throw(INTERP_KERNEL::Exception)
+void MEDCouplingStructuredMesh::copyTinyStringsFrom(const MEDCouplingMesh *other)
 {
   MEDCouplingMesh::copyTinyStringsFrom(other);
 }
 
-bool MEDCouplingStructuredMesh::isEqualIfNotWhy(const MEDCouplingMesh *other, double prec, std::string& reason) const throw(INTERP_KERNEL::Exception)
+bool MEDCouplingStructuredMesh::isEqualIfNotWhy(const MEDCouplingMesh *other, double prec, std::string& reason) const
 {
   return MEDCouplingMesh::isEqualIfNotWhy(other,prec,reason);
 }
 
 INTERP_KERNEL::NormalizedCellType MEDCouplingStructuredMesh::getTypeOfCell(int cellId) const
 {
-  switch(getMeshDimension())
+  return GetGeoTypeGivenMeshDimension(getMeshDimension());
+}
+
+INTERP_KERNEL::NormalizedCellType MEDCouplingStructuredMesh::GetGeoTypeGivenMeshDimension(int meshDim)
+{
+  switch(meshDim)
     {
     case 3:
       return INTERP_KERNEL::NORM_HEXA8;
@@ -64,8 +70,10 @@ INTERP_KERNEL::NormalizedCellType MEDCouplingStructuredMesh::getTypeOfCell(int c
       return INTERP_KERNEL::NORM_QUAD4;
     case 1:
       return INTERP_KERNEL::NORM_SEG2;
+    case 0:
+      return INTERP_KERNEL::NORM_POINT1;
     default:
-      throw INTERP_KERNEL::Exception("Unexpected dimension for MEDCouplingCurveLinearMesh::getTypeOfCell !");
+      throw INTERP_KERNEL::Exception("Unexpected dimension for MEDCouplingStructuredMesh::GetGeoTypeGivenMeshDimension !");
     }
 }
 
@@ -86,7 +94,7 @@ int MEDCouplingStructuredMesh::getNumberOfCellsWithType(INTERP_KERNEL::Normalize
   throw INTERP_KERNEL::Exception(oss.str().c_str());
 }
 
-DataArrayInt *MEDCouplingStructuredMesh::giveCellsWithType(INTERP_KERNEL::NormalizedCellType type) const throw(INTERP_KERNEL::Exception)
+DataArrayInt *MEDCouplingStructuredMesh::giveCellsWithType(INTERP_KERNEL::NormalizedCellType type) const
 {
   MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
   if(getTypeOfCell(0)==type)
@@ -99,7 +107,7 @@ DataArrayInt *MEDCouplingStructuredMesh::giveCellsWithType(INTERP_KERNEL::Normal
   return ret.retn();
 }
 
-DataArrayInt *MEDCouplingStructuredMesh::computeNbOfNodesPerCell() const throw(INTERP_KERNEL::Exception)
+DataArrayInt *MEDCouplingStructuredMesh::computeNbOfNodesPerCell() const
 {
   int nbCells=getNumberOfCells();
   MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
@@ -109,6 +117,28 @@ DataArrayInt *MEDCouplingStructuredMesh::computeNbOfNodesPerCell() const throw(I
   return ret.retn();
 }
 
+DataArrayInt *MEDCouplingStructuredMesh::computeNbOfFacesPerCell() const
+{
+  int nbCells=getNumberOfCells();
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
+  ret->alloc(nbCells,1);
+  const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(getTypeOfCell(0));
+  ret->fillWithValue((int)cm.getNumberOfSons());
+  return ret.retn();
+}
+
+/*!
+ * This method computes effective number of nodes per cell. That is to say nodes appearing several times in nodal connectivity of a cell,
+ * will be counted only once here whereas it will be counted several times in MEDCouplingMesh::computeNbOfNodesPerCell method.
+ * Here for structured mesh it returns exactly as MEDCouplingStructuredMesh::computeNbOfNodesPerCell does.
+ *
+ * \return DataArrayInt * - new object to be deallocated by the caller.
+ */
+DataArrayInt *MEDCouplingStructuredMesh::computeEffectiveNbOfNodesPerCell() const
+{
+  return computeNbOfNodesPerCell();
+}
+
 void MEDCouplingStructuredMesh::getNodeIdsOfCell(int cellId, std::vector<int>& conn) const
 {
   int meshDim=getMeshDimension();
@@ -123,13 +153,13 @@ void MEDCouplingStructuredMesh::getNodeIdsOfCell(int cellId, std::vector<int>& c
       conn.push_back(tmp2[0]); conn.push_back(tmp2[0]+1);
       break;
     case 2:
-      conn.push_back(tmp2[1]*tmpCell[1]+tmp2[0]); conn.push_back(tmp2[1]*tmpCell[1]+tmp2[0]+1);
-      conn.push_back((tmp2[1]+1)*(tmpCell[1]+1)+tmp2[0]+1); conn.push_back((tmp2[1]+1)*(tmpCell[1]+1)+tmp2[0]);
+      conn.push_back(tmp2[1]*tmpNode[1]+tmp2[0]); conn.push_back(tmp2[1]*tmpNode[1]+tmp2[0]+1);
+      conn.push_back((tmp2[1]+1)*tmpNode[1]+tmp2[0]+1); conn.push_back((tmp2[1]+1)*tmpNode[1]+tmp2[0]);
       break;
     case 3:
-      conn.push_back(tmp2[1]*tmpCell[1]+tmp2[0]+tmp2[2]*tmpNode[2]); conn.push_back(tmp2[1]*tmpCell[1]+tmp2[0]+1+tmp2[2]*tmpNode[2]);
+      conn.push_back(tmp2[1]*tmpNode[1]+tmp2[0]+tmp2[2]*tmpNode[2]); conn.push_back(tmp2[1]*tmpNode[1]+tmp2[0]+1+tmp2[2]*tmpNode[2]);
       conn.push_back((tmp2[1]+1)*tmpNode[1]+tmp2[0]+1+tmp2[2]*tmpNode[2]); conn.push_back((tmp2[1]+1)*tmpNode[1]+tmp2[0]+tmp2[2]*tmpNode[2]);
-      conn.push_back(tmp2[1]*tmpCell[1]+tmp2[0]+(tmp2[2]+1)*tmpNode[2]); conn.push_back(tmp2[1]*tmpCell[1]+tmp2[0]+1+(tmp2[2]+1)*tmpNode[2]);
+      conn.push_back(tmp2[1]*tmpNode[1]+tmp2[0]+(tmp2[2]+1)*tmpNode[2]); conn.push_back(tmp2[1]*tmpNode[1]+tmp2[0]+1+(tmp2[2]+1)*tmpNode[2]);
       conn.push_back((tmp2[1]+1)*tmpNode[1]+tmp2[0]+1+(tmp2[2]+1)*tmpNode[2]); conn.push_back((tmp2[1]+1)*tmpNode[1]+tmp2[0]+(tmp2[2]+1)*tmpNode[2]);
       break;
     default:
@@ -140,83 +170,148 @@ void MEDCouplingStructuredMesh::getNodeIdsOfCell(int cellId, std::vector<int>& c
 /*!
  * See MEDCouplingUMesh::getDistributionOfTypes for more information
  */
-std::vector<int> MEDCouplingStructuredMesh::getDistributionOfTypes() const throw(INTERP_KERNEL::Exception)
+std::vector<int> MEDCouplingStructuredMesh::getDistributionOfTypes() const
 {
   //only one type of cell
   std::vector<int> ret(3);
   ret[0]=getTypeOfCell(0);
   ret[1]=getNumberOfCells();
-  ret[2]=0; //ret[3*k+2]==0 because it has no sense here
+  ret[2]=-1; //ret[3*k+2]==-1 because it has no sense here
   return ret;
 }
 
 /*!
+ * This method tries to minimize at most the number of deep copy.
+ * So if \a idsPerType is not empty it can be returned directly (without copy, but with ref count incremented) in return.
+ * 
  * See MEDCouplingUMesh::checkTypeConsistencyAndContig for more information
  */
-DataArrayInt *MEDCouplingStructuredMesh::checkTypeConsistencyAndContig(const std::vector<int>& code, const std::vector<const DataArrayInt *>& idsPerType) const throw(INTERP_KERNEL::Exception)
+DataArrayInt *MEDCouplingStructuredMesh::checkTypeConsistencyAndContig(const std::vector<int>& code, const std::vector<const DataArrayInt *>& idsPerType) const
 {
-  if(code.empty())
-    throw INTERP_KERNEL::Exception("MEDCouplingCurveLinearMesh::checkTypeConsistencyAndContig : code is empty, should not !");
-  std::size_t sz=code.size();
-  if(sz!=3)
-    throw INTERP_KERNEL::Exception("MEDCouplingCurveLinearMesh::checkTypeConsistencyAndContig : code should be of size 3 exactly !");
-
-  int nbCells=getNumberOfCellsWithType((INTERP_KERNEL::NormalizedCellType)code[0]);
+  int nbOfCells=getNumberOfCells();
+  if(code.size()!=3)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : invalid input code should be exactly of size 3 !");
+  if(code[0]!=(int)getTypeOfCell(0))
+    {
+      std::ostringstream oss; oss << "MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : Mismatch of geometric type ! Asking for " << code[0] << " whereas the geometric type is \a this is " << getTypeOfCell(0) << " !";
+      throw INTERP_KERNEL::Exception(oss.str().c_str());
+    }
   if(code[2]==-1)
     {
-      if(code[1]==nbCells)
+      if(code[1]==nbOfCells)
         return 0;
       else
-        throw INTERP_KERNEL::Exception("MEDCouplingCurveLinearMesh::checkTypeConsistencyAndContig : number of cells mismatch !");
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : mismatch between the number of cells in this (" << nbOfCells << ") and the number of non profile (" << code[1] << ") !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
     }
-  else
+  if(code[2]!=0)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : single geo type mesh ! 0 or -1 is expected at pos #2 of input code !");
+  if(idsPerType.size()!=1)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : input code points to DataArrayInt #0 whereas the size of idsPerType is not equal to 1 !");
+  const DataArrayInt *pfl=idsPerType[0];
+  if(!pfl)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : the input code points to a NULL DataArrayInt at rank 0 !");
+  if(pfl->getNumberOfComponents()!=1)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::checkTypeConsistencyAndContig : input profile should have exactly one component !");
+  pfl->checkAllIdsInRange(0,nbOfCells);
+  pfl->incrRef();
+  return const_cast<DataArrayInt *>(pfl);
+}
+
+/*!
+ * 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.
+ * 
+ * \warning for performance reasons no deep copy will be performed, if \a profile can been used as this in output parameters \a idsInPflPerType and \a idsPerType.
+ *
+ * \throw if \a profile has not exactly one component. It throws too, if \a profile contains some values not in [0,getNumberOfCells()) or if \a this is not fully defined
+ *
+ *  \b Example1: <br>
+ *          - Before \a this has 3 cells \a profile contains [0,1,2]
+ *          - After \a code contains [NORM_...,nbCells,-1], \a idsInPflPerType [[0,1,2]] and \a idsPerType is empty <br>
+ * 
+ *  \b Example2: <br>
+ *          - Before \a this has 3 cells \a profile contains [1,2]
+ *          - After \a code contains [NORM_...,nbCells,0], \a idsInPflPerType [[0,1]] and \a idsPerType is [[1,2]] <br>
+
+ */
+void MEDCouplingStructuredMesh::splitProfilePerType(const DataArrayInt *profile, std::vector<int>& code, std::vector<DataArrayInt *>& idsInPflPerType, std::vector<DataArrayInt *>& idsPerType) const
+{
+  if(!profile || !profile->isAllocated())
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::splitProfilePerType : input profile is NULL or not allocated !");
+  if(profile->getNumberOfComponents()!=1)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::splitProfilePerType : input profile should have exactly one component !");
+  int nbTuples=profile->getNumberOfTuples();
+  int nbOfCells=getNumberOfCells();
+  code.resize(3); idsInPflPerType.resize(1);
+  code[0]=(int)getTypeOfCell(0); code[1]=nbOfCells;
+  idsInPflPerType.resize(1);
+  if(profile->isIdentity() && nbTuples==nbOfCells)
     {
-      if(code[2]<-1) 
-        throw INTERP_KERNEL::Exception("MEDCouplingCurveLinearMesh::checkTypeConsistencyAndContig : code[2]<-1 mismatch !");
-      if(code[2]>=(int)idsPerType.size()) 
-        throw INTERP_KERNEL::Exception("MEDCouplingCurveLinearMesh::checkTypeConsistencyAndContig : code[2]>size idsPerType !");
-      return idsPerType[code[2]]->deepCpy();
+      code[2]=-1;
+      idsInPflPerType[0]=0;
+      idsPerType.clear();
+      return ;
     }
+  code[1]=profile->getNumberOfTuples();
+  code[2]=0;
+  profile->checkAllIdsInRange(0,nbOfCells);
+  idsPerType.resize(1);
+  idsPerType[0]=profile->deepCpy();
+  idsInPflPerType[0]=DataArrayInt::Range(0,nbTuples,1);
 }
 
 /*!
- * See MEDCouplingUMesh::splitProfilePerType for more information
+ * Creates a new unstructured mesh (MEDCoupling1SGTUMesh) from \a this structured one.
+ *  \return MEDCouplingUMesh * - a new instance of MEDCouplingUMesh. The caller is to
+ * delete this array using decrRef() as it is no more needed. 
+ *  \throw If \a this->getMeshDimension() is not among [1,2,3].
  */
-void MEDCouplingStructuredMesh::splitProfilePerType(const DataArrayInt *profile, std::vector<int>& code, std::vector<DataArrayInt *>& idsInPflPerType, std::vector<DataArrayInt *>& idsPerType) const throw(INTERP_KERNEL::Exception)
+MEDCoupling1SGTUMesh *MEDCouplingStructuredMesh::build1SGTUnstructured() const
 {
-  int nbCells=getNumberOfCells();
-  code.resize(3);
-  code[0]=(int)getTypeOfCell(0);
-  code[1]=nbCells;
-  code[2]=0;
-  idsInPflPerType.push_back(profile->deepCpy());
-  idsPerType.push_back(profile->deepCpy());
+  int meshDim=getMeshDimension(); 
+  if(meshDim<0 || meshDim>3)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::build1SGTUnstructured : meshdim must be in [1,2,3] !");
+  MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> coords(getCoordinatesAndOwner());
+  int ns[3];
+  getNodeGridStructure(ns);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(Build1GTNodalConnectivity(ns,ns+meshDim));
+  MEDCouplingAutoRefCountObjectPtr<MEDCoupling1SGTUMesh> ret(MEDCoupling1SGTUMesh::New(getName(),GetGeoTypeGivenMeshDimension(meshDim)));
+  ret->setNodalConnectivity(conn); ret->setCoords(coords);
+  return ret.retn();
 }
 
-MEDCouplingUMesh *MEDCouplingStructuredMesh::buildUnstructured() const throw(INTERP_KERNEL::Exception)
+/*!
+ * Creates a new unstructured mesh (MEDCouplingUMesh) from \a this structured one.
+ *  \return MEDCouplingUMesh * - a new instance of MEDCouplingUMesh. The caller is to
+ * delete this array using decrRef() as it is no more needed. 
+ *  \throw If \a this->getMeshDimension() is not among [1,2,3].
+ */
+MEDCouplingUMesh *MEDCouplingStructuredMesh::buildUnstructured() const
 {
-  int meshDim=getMeshDimension();
-  MEDCouplingUMesh *ret=MEDCouplingUMesh::New(getName(),meshDim);
-  DataArrayDouble *coords=getCoordinatesAndOwner();
-  ret->setCoords(coords);
-  coords->decrRef();
-  switch(meshDim)
-    {
-    case 1:
-      fill1DUnstructuredMesh(ret);
-      break;
-    case 2:
-      fill2DUnstructuredMesh(ret);
-      break;
-    case 3:
-      fill3DUnstructuredMesh(ret);
-      break;
-    default:
-      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::buildUnstructured : big problem spacedim must be in 1,2 or 3 !");
-    };
-  return ret;
+  MEDCouplingAutoRefCountObjectPtr<MEDCoupling1SGTUMesh> ret0(build1SGTUnstructured());
+  return ret0->buildUnstructured();
 }
 
+/*!
+ * Creates a new MEDCouplingUMesh containing a part of cells of \a this mesh.
+ * The cells to include to the
+ * result mesh are specified by an array of cell ids.
+ *  \param [in] start - an array of cell ids to include to the result mesh.
+ *  \param [in] end - specifies the end of the array \a start, so that
+ *              the last value of \a start is \a end[ -1 ].
+ *  \return MEDCouplingMesh * - a new instance of MEDCouplingUMesh. The caller is to
+ *         delete this mesh using decrRef() as it is no more needed. 
+ */
 MEDCouplingMesh *MEDCouplingStructuredMesh::buildPart(const int *start, const int *end) const
 {
   MEDCouplingUMesh *um=buildUnstructured();
@@ -227,17 +322,44 @@ MEDCouplingMesh *MEDCouplingStructuredMesh::buildPart(const int *start, const in
 
 MEDCouplingMesh *MEDCouplingStructuredMesh::buildPartAndReduceNodes(const int *start, const int *end, DataArrayInt*& arr) const
 {
-  MEDCouplingUMesh *um=buildUnstructured();
-  MEDCouplingMesh *ret=um->buildPartAndReduceNodes(start,end,arr);
-  um->decrRef();
-  return ret;
+  std::vector<int> cgs(getCellGridStructure());
+  std::vector< std::pair<int,int> > cellPartFormat,nodePartFormat;
+  if(IsPartStructured(start,end,cgs,cellPartFormat))
+    {
+      MEDCouplingAutoRefCountObjectPtr<MEDCouplingStructuredMesh> ret(buildStructuredSubPart(cellPartFormat));
+      nodePartFormat=cellPartFormat;
+      for(std::vector< std::pair<int,int> >::iterator it=nodePartFormat.begin();it!=nodePartFormat.end();it++)
+        (*it).second++;
+      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp1(BuildExplicitIdsFrom(getNodeGridStructure(),nodePartFormat));
+      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp2(DataArrayInt::New()); tmp2->alloc(getNumberOfNodes(),1);
+      tmp2->fillWithValue(-1);
+      MEDCouplingAutoRefCountObjectPtr<DataArrayInt> tmp3(DataArrayInt::New()); tmp3->alloc(tmp1->getNumberOfTuples(),1); tmp3->iota(0);
+      tmp2->setPartOfValues3(tmp3,tmp1->begin(),tmp1->end(),0,1,1);
+      arr=tmp2.retn();
+      return ret.retn();
+    }
+  else
+    {
+      MEDCouplingUMesh *um=buildUnstructured();
+      MEDCouplingMesh *ret=um->buildPartAndReduceNodes(start,end,arr);
+      um->decrRef();
+      return ret;
+    }
 }
 
-DataArrayInt *MEDCouplingStructuredMesh::simplexize(int policy) throw(INTERP_KERNEL::Exception)
+DataArrayInt *MEDCouplingStructuredMesh::simplexize(int policy)
 {
   throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::simplexize : not available for Cartesian mesh !");
 }
 
+/*!
+ * Returns a new MEDCouplingFieldDouble holding normal vectors to cells of \a this
+ * 2D mesh. The computed vectors have 3 components and are normalized.
+ *  \return MEDCouplingFieldDouble * - a new instance of MEDCouplingFieldDouble on
+ *          cells and one time. The caller is to delete this field using decrRef() as
+ *          it is no more needed.
+ *  \throw If \a this->getMeshDimension() != 2.
+ */
 MEDCouplingFieldDouble *MEDCouplingStructuredMesh::buildOrthogonalField() const
 {
   if(getMeshDimension()!=2)
@@ -255,113 +377,278 @@ MEDCouplingFieldDouble *MEDCouplingStructuredMesh::buildOrthogonalField() const
   return ret;
 }
 
-void MEDCouplingStructuredMesh::fill1DUnstructuredMesh(MEDCouplingUMesh *m) const
+void MEDCouplingStructuredMesh::getReverseNodalConnectivity(DataArrayInt *revNodal, DataArrayInt *revNodalIndx) const
+{
+  std::vector<int> ngs(getNodeGridStructure());
+  int dim(getSpaceDimension());
+  switch(dim)
+  {
+    case 1:
+      return GetReverseNodalConnectivity1(ngs,revNodal,revNodalIndx);
+    case 2:
+      return GetReverseNodalConnectivity2(ngs,revNodal,revNodalIndx);
+    case 3:
+      return GetReverseNodalConnectivity3(ngs,revNodal,revNodalIndx);
+    default:
+      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::getReverseNodalConnectivity : only dimensions 1, 2 and 3 are supported !");
+  }
+}
+
+void MEDCouplingStructuredMesh::GetReverseNodalConnectivity1(const std::vector<int>& ngs, DataArrayInt *revNodal, DataArrayInt *revNodalIndx)
 {
-  int nbOfCells=-1;
-  getNodeGridStructure(&nbOfCells);
-  nbOfCells--;
-  DataArrayInt *connI=DataArrayInt::New();
-  connI->alloc(nbOfCells+1,1);
-  int *ci=connI->getPointer();
-  DataArrayInt *conn=DataArrayInt::New();
-  conn->alloc(3*nbOfCells,1);
-  ci[0]=0;
+  int nbNodes(ngs[0]);
+  revNodalIndx->alloc(nbNodes+1,1);
+  if(nbNodes==0)
+    { revNodal->alloc(0,1); revNodalIndx->setIJ(0,0,0); return ; }
+  if(nbNodes==1)
+    { revNodal->alloc(1,1); revNodal->setIJ(0,0,0); revNodalIndx->setIJ(0,0,0); revNodalIndx->setIJ(1,0,1); return ; }
+  revNodal->alloc(2*(nbNodes-1),1);
+  int *rn(revNodal->getPointer()),*rni(revNodalIndx->getPointer());
+  *rni++=0; *rni=1; *rn++=0;
+  for(int i=1;i<nbNodes-1;i++,rni++)
+    {
+      rn[0]=i-1; rn[1]=i;
+      rni[1]=rni[0]+2;
+      rn+=2;
+    }
+  rn[0]=nbNodes-2; rni[1]=rni[0]+1;
+}
+
+void MEDCouplingStructuredMesh::GetReverseNodalConnectivity2(const std::vector<int>& ngs, DataArrayInt *revNodal, DataArrayInt *revNodalIndx)
+{
+  int nbNodesX(ngs[0]),nbNodesY(ngs[1]);
+  int nbNodes(nbNodesX*nbNodesY);
+  if(nbNodesX==0 || nbNodesY==0)
+    { revNodal->alloc(0,1); revNodalIndx->setIJ(0,0,0); return ; }
+  if(nbNodesX==1 || nbNodesY==1)
+    { std::vector<int> ngs2(1); ngs2[0]=std::max(nbNodesX,nbNodesY); return GetReverseNodalConnectivity1(ngs2,revNodal,revNodalIndx); }
+  revNodalIndx->alloc(nbNodes+1,1);
+  int nbCellsX(nbNodesX-1),nbCellsY(nbNodesY-1);
+  revNodal->alloc(4*(nbNodesX-2)*(nbNodesY-2)+2*2*(nbNodesX-2)+2*2*(nbNodesY-2)+4,1);
+  int *rn(revNodal->getPointer()),*rni(revNodalIndx->getPointer());
+  *rni++=0; *rni=1; *rn++=0;
+  for(int i=1;i<nbNodesX-1;i++,rni++,rn+=2)
+    {
+      rn[0]=i-1; rn[1]=i;
+      rni[1]=rni[0]+2;
+    }
+  rni[1]=rni[0]+1; *rn++=nbCellsX-1;
+  rni++;
+  for(int j=1;j<nbNodesY-1;j++)
+    {
+      int off(nbCellsX*(j-1)),off2(nbCellsX*j);
+      rni[1]=rni[0]+2; rn[0]=off; rn[1]=off2;
+      rni++; rn+=2;
+      for(int i=1;i<nbNodesX-1;i++,rni++,rn+=4)
+        {
+          rn[0]=i-1+off; rn[1]=i+off; rn[2]=i-1+off2; rn[3]=i+off2;
+          rni[1]=rni[0]+4;
+        }
+      rni[1]=rni[0]+2; rn[0]=off+nbCellsX-1; rn[1]=off2+nbCellsX-1;
+      rni++; rn+=2;
+    }
+  int off3(nbCellsX*(nbCellsY-1));
+  rni[1]=rni[0]+1;
+  rni++; *rn++=off3;
+  for(int i=1;i<nbNodesX-1;i++,rni++,rn+=2)
+    {
+      rn[0]=i-1+off3; rn[1]=i+off3;
+      rni[1]=rni[0]+2;
+    }
+  rni[1]=rni[0]+1; rn[0]=nbCellsX*nbCellsY-1;
+}
+
+void MEDCouplingStructuredMesh::GetReverseNodalConnectivity3(const std::vector<int>& ngs, DataArrayInt *revNodal, DataArrayInt *revNodalIndx)
+{
+  int nbNodesX(ngs[0]),nbNodesY(ngs[1]),nbNodesZ(ngs[2]);
+  int nbNodes(nbNodesX*nbNodesY*nbNodesZ);
+  if(nbNodesX==0 || nbNodesY==0 || nbNodesZ==0)
+    { revNodal->alloc(0,1); revNodalIndx->setIJ(0,0,0); return ; }
+  if(nbNodesX==1 || nbNodesY==1 || nbNodesZ==1)
+    {
+      std::vector<int> ngs2(2);
+      int pos(0);
+      bool pass(false);
+      for(int i=0;i<3;i++)
+        {
+          if(pass)
+            { ngs2[pos++]=ngs[i]; }
+          else
+            {
+              pass=ngs[i]==1;
+              if(!pass)
+                { ngs2[pos++]=ngs[i]; }
+            }
+        }
+      return GetReverseNodalConnectivity2(ngs2,revNodal,revNodalIndx);
+    }
+  revNodalIndx->alloc(nbNodes+1,1);
+  int nbCellsX(nbNodesX-1),nbCellsY(nbNodesY-1),nbCellsZ(nbNodesZ-1);
+  revNodal->alloc(8*(nbNodesX-2)*(nbNodesY-2)*(nbNodesZ-2)+4*(2*(nbNodesX-2)*(nbNodesY-2)+2*(nbNodesX-2)*(nbNodesZ-2)+2*(nbNodesY-2)*(nbNodesZ-2))+2*4*(nbNodesX-2)+2*4*(nbNodesY-2)+2*4*(nbNodesZ-2)+8,1);
+  int *rn(revNodal->getPointer()),*rni(revNodalIndx->getPointer());
+  *rni=0;
+  for(int k=0;k<nbNodesZ;k++)
+    {
+      bool factZ(k!=0 && k!=nbNodesZ-1);
+      int offZ0((k-1)*nbCellsX*nbCellsY),offZ1(k*nbCellsX*nbCellsY);
+      for(int j=0;j<nbNodesY;j++)
+        {
+          bool factYZ(factZ && (j!=0 && j!=nbNodesY-1));
+          int off00((j-1)*nbCellsX+offZ0),off01(j*nbCellsX+offZ0),off10((j-1)*nbCellsX+offZ1),off11(j*nbCellsX+offZ1);
+          for(int i=0;i<nbNodesX;i++,rni++)
+            {
+              int fact(factYZ && (i!=0 && i!=nbNodesX-1));
+              if(fact)
+                {//most of points fall in this part of code
+                  rn[0]=off00+i-1; rn[1]=off00+i; rn[2]=off01+i-1; rn[3]=off01+i;
+                  rn[4]=off10+i-1; rn[5]=off10+i; rn[6]=off11+i-1; rn[7]=off11+i;
+                  rni[1]=rni[0]+8;
+                  rn+=8;
+                }
+              else
+                {
+                  int *rnRef(rn);
+                  if(k>=1 && j>=1 && i>=1)
+                    *rn++=off00+i-1;
+                  if(k>=1 && j>=1 && i<nbCellsX)
+                    *rn++=off00+i;
+                  if(k>=1 && j<nbCellsY && i>=1)
+                    *rn++=off01+i-1;
+                  if(k>=1 && j<nbCellsY && i<nbCellsX)
+                    *rn++=off01+i;
+                  //
+                  if(k<nbCellsZ && j>=1 && i>=1)
+                    *rn++=off10+i-1;
+                  if(k<nbCellsZ && j>=1 && i<nbCellsX)
+                    *rn++=off10+i;
+                  if(k<nbCellsZ && j<nbCellsY && i>=1)
+                    *rn++=off11+i-1;
+                  if(k<nbCellsZ && j<nbCellsY && i<nbCellsX)
+                    *rn++=off11+i;
+                  rni[1]=rni[0]+(int)(std::distance(rnRef,rn));
+                }
+            }
+        }
+    }
+}
+
+/*!
+ * \return DataArrayInt * - newly allocated instance of nodal connectivity compatible for MEDCoupling1SGTMesh instance
+ */
+DataArrayInt *MEDCouplingStructuredMesh::Build1GTNodalConnectivity(const int *nodeStBg, const int *nodeStEnd)
+{
+  std::size_t dim=std::distance(nodeStBg,nodeStEnd);
+  switch(dim)
+    {
+    case 0:
+      {
+        MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(DataArrayInt::New());
+        conn->alloc(1,1); conn->setIJ(0,0,0);
+        return conn.retn();
+      }
+    case 1:
+      return Build1GTNodalConnectivity1D(nodeStBg);
+    case 2:
+      return Build1GTNodalConnectivity2D(nodeStBg);
+    case 3:
+      return Build1GTNodalConnectivity3D(nodeStBg);
+    default:
+      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::Build1GTNodalConnectivity : only dimension in [0,1,2,3] supported !");
+    }
+}
+
+DataArrayInt *MEDCouplingStructuredMesh::Build1GTNodalConnectivity1D(const int *nodeStBg)
+{
+  int nbOfCells(*nodeStBg-1);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(DataArrayInt::New());
+  conn->alloc(2*nbOfCells,1);
   int *cp=conn->getPointer();
   for(int i=0;i<nbOfCells;i++)
     {
-      cp[3*i]=(int)INTERP_KERNEL::NORM_SEG2;
-      cp[3*i+1]=i;
-      cp[3*i+2]=i+1;
-      ci[i+1]=3*(i+1);
+      cp[2*i+0]=i;
+      cp[2*i+1]=i+1;
     }
-  m->setConnectivity(conn,connI,true);
-  conn->decrRef();
-  connI->decrRef();
+  return conn.retn();
 }
 
-void MEDCouplingStructuredMesh::fill2DUnstructuredMesh(MEDCouplingUMesh *m) const
+DataArrayInt *MEDCouplingStructuredMesh::Build1GTNodalConnectivity2D(const int *nodeStBg)
 {
-  int ns[2];
-  getNodeGridStructure(ns);
-  int n1=ns[0]-1;
-  int n2=ns[1]-1;
-  DataArrayInt *connI=DataArrayInt::New();
-  connI->alloc(n1*n2+1,1);
-  int *ci=connI->getPointer();
-  DataArrayInt *conn=DataArrayInt::New();
-  conn->alloc(5*n1*n2,1);
-  ci[0]=0;
+  int n1=nodeStBg[0]-1;
+  int n2=nodeStBg[1]-1;
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(DataArrayInt::New());
+  conn->alloc(4*n1*n2,1);
   int *cp=conn->getPointer();
   int pos=0;
   for(int j=0;j<n2;j++)
     for(int i=0;i<n1;i++,pos++)
       {
-        cp[5*pos]=(int)INTERP_KERNEL::NORM_QUAD4;
-        cp[5*pos+1]=i+1+j*(n1+1);
-        cp[5*pos+2]=i+j*(n1+1);
-        cp[5*pos+3]=i+(j+1)*(n1+1);
-        cp[5*pos+4]=i+1+(j+1)*(n1+1);
-        ci[pos+1]=5*(pos+1);
+        cp[4*pos+0]=i+1+j*(n1+1);
+        cp[4*pos+1]=i+j*(n1+1);
+        cp[4*pos+2]=i+(j+1)*(n1+1);
+        cp[4*pos+3]=i+1+(j+1)*(n1+1);
     }
-  m->setConnectivity(conn,connI,true);
-  conn->decrRef();
-  connI->decrRef();
+  return conn.retn();
 }
 
-void MEDCouplingStructuredMesh::fill3DUnstructuredMesh(MEDCouplingUMesh *m) const
+DataArrayInt *MEDCouplingStructuredMesh::Build1GTNodalConnectivity3D(const int *nodeStBg)
 {
-  int ns[3];
-  getNodeGridStructure(ns);
-  int n1=ns[0]-1;
-  int n2=ns[1]-1;
-  int n3=ns[2]-1;
-  DataArrayInt *connI=DataArrayInt::New();
-  connI->alloc(n1*n2*n3+1,1);
-  int *ci=connI->getPointer();
-  DataArrayInt *conn=DataArrayInt::New();
-  conn->alloc(9*n1*n2*n3,1);
-  ci[0]=0;
+  int n1=nodeStBg[0]-1;
+  int n2=nodeStBg[1]-1;
+  int n3=nodeStBg[2]-1;
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> conn(DataArrayInt::New());
+  conn->alloc(8*n1*n2*n3,1);
   int *cp=conn->getPointer();
   int pos=0;
   for(int k=0;k<n3;k++)
     for(int j=0;j<n2;j++)
       for(int i=0;i<n1;i++,pos++)
         {
-          cp[9*pos]=(int)INTERP_KERNEL::NORM_HEXA8;
           int tmp=(n1+1)*(n2+1);
-          cp[9*pos+1]=i+1+j*(n1+1)+k*tmp;
-          cp[9*pos+2]=i+j*(n1+1)+k*tmp;
-          cp[9*pos+3]=i+(j+1)*(n1+1)+k*tmp;
-          cp[9*pos+4]=i+1+(j+1)*(n1+1)+k*tmp;
-          cp[9*pos+5]=i+1+j*(n1+1)+(k+1)*tmp;
-          cp[9*pos+6]=i+j*(n1+1)+(k+1)*tmp;
-          cp[9*pos+7]=i+(j+1)*(n1+1)+(k+1)*tmp;
-          cp[9*pos+8]=i+1+(j+1)*(n1+1)+(k+1)*tmp;
-          ci[pos+1]=9*(pos+1);
+          cp[8*pos+0]=i+1+j*(n1+1)+k*tmp;
+          cp[8*pos+1]=i+j*(n1+1)+k*tmp;
+          cp[8*pos+2]=i+(j+1)*(n1+1)+k*tmp;
+          cp[8*pos+3]=i+1+(j+1)*(n1+1)+k*tmp;
+          cp[8*pos+4]=i+1+j*(n1+1)+(k+1)*tmp;
+          cp[8*pos+5]=i+j*(n1+1)+(k+1)*tmp;
+          cp[8*pos+6]=i+(j+1)*(n1+1)+(k+1)*tmp;
+          cp[8*pos+7]=i+1+(j+1)*(n1+1)+(k+1)*tmp;
         }
-  m->setConnectivity(conn,connI,true);
-  conn->decrRef();
-  connI->decrRef();
+  return conn.retn();
 }
 
+/*!
+ * Returns a cell id by its (i,j,k) index. The cell is located between the i-th and
+ * ( i + 1 )-th nodes along X axis etc.
+ *  \param [in] i - a index of node coordinates array along X axis.
+ *  \param [in] j - a index of node coordinates array along Y axis.
+ *  \param [in] k - a index of node coordinates array along Z axis.
+ *  \return int - a cell id in \a this mesh.
+ */
 int MEDCouplingStructuredMesh::getCellIdFromPos(int i, int j, int k) const
 {
   int tmp[3]={i,j,k};
   int tmp2[3];
-  int meshDim=getMeshDimension();
+  int meshDim(getMeshDimension());
   getSplitCellValues(tmp2);
   std::transform(tmp,tmp+meshDim,tmp2,tmp,std::multiplies<int>());
   return std::accumulate(tmp,tmp+meshDim,0);
 }
 
+/*!
+ * Returns a node id by its (i,j,k) index.
+ *  \param [in] i - a index of node coordinates array along X axis.
+ *  \param [in] j - a index of node coordinates array along Y axis.
+ *  \param [in] k - a index of node coordinates array along Z axis.
+ *  \return int - a node id in \a this mesh.
+ */
 int MEDCouplingStructuredMesh::getNodeIdFromPos(int i, int j, int k) const
 {
   int tmp[3]={i,j,k};
   int tmp2[3];
-  int meshDim=getMeshDimension();
+  int spaceDim(getSpaceDimension());
   getSplitNodeValues(tmp2);
-  std::transform(tmp,tmp+meshDim,tmp2,tmp,std::multiplies<int>());
-  return std::accumulate(tmp,tmp+meshDim,0);
+  std::transform(tmp,tmp+spaceDim,tmp2,tmp,std::multiplies<int>());
+  return std::accumulate(tmp,tmp+spaceDim,0);
 }
 
 void MEDCouplingStructuredMesh::GetPosFromId(int nodeId, int meshDim, const int *split, int *res)
@@ -374,3 +661,166 @@ void MEDCouplingStructuredMesh::GetPosFromId(int nodeId, int meshDim, const int
       res[i]=pos;
     }
 }
+
+std::vector<int> MEDCouplingStructuredMesh::getCellGridStructure() const
+{
+  std::vector<int> ret(getNodeGridStructure());
+  std::transform(ret.begin(),ret.end(),ret.begin(),std::bind2nd(std::plus<int>(),-1));
+  return ret;
+}
+
+/*!
+ * This method states if given part ids [ \a startIds, \a stopIds) and a structure \a st returns if it can be considered as a structured dataset.
+ * If true is returned \a partCompactFormat will contain the information to build the corresponding part.
+ *
+ * \sa MEDCouplingStructuredMesh::BuildExplicitIdsFrom
+ */
+bool MEDCouplingStructuredMesh::IsPartStructured(const int *startIds, const int *stopIds, const std::vector<int>& st, std::vector< std::pair<int,int> >& partCompactFormat)
+{
+  int dim((int)st.size());
+  partCompactFormat.resize(dim);
+  if(dim<1 || dim>3)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::isPartStructured : input structure must be of dimension in [1,2,3] !");
+  std::vector<int> tmp2(dim),tmp(dim),tmp3(dim),tmp4(dim); tmp2[0]=1;
+  for(int i=1;i<dim;i++)
+    tmp2[i]=tmp2[i-1]*st[i-1];
+  std::size_t sz(std::distance(startIds,stopIds));
+  if(sz==0)
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::IsPartStructured : empty input !");
+  GetPosFromId(*startIds,dim,&tmp2[0],&tmp[0]);
+  partCompactFormat.resize(dim);
+  for(int i=0;i<dim;i++)
+    partCompactFormat[i].first=tmp[i];
+  if(tmp[dim-1]<0 || tmp[dim-1]>=st[dim-1])
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::IsPartStructured : first id in input is not in valid range !");
+  if(sz==1)
+    {
+      for(int i=0;i<dim;i++)
+        partCompactFormat[i].second=tmp[i]+1;
+      return true;
+    }
+  GetPosFromId(startIds[sz-1],dim,&tmp2[0],&tmp3[0]);
+  int szExp(1);
+  for(int i=0;i<dim;i++)
+    {
+      if(tmp3[i]<0 || tmp3[i]>=st[i])
+        throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::IsPartStructured : last id in input is not in valid range !");
+      partCompactFormat[i].second=tmp3[i]+1;
+      tmp4[i]=partCompactFormat[i].second-partCompactFormat[i].first;
+      if(tmp4[i]<=0)
+        return false;
+      szExp*=tmp4[i];
+    }
+  if(szExp!=(int)sz)
+    return false;
+  const int *w(startIds);
+  switch(dim)
+    {
+    case 3:
+      {
+        for(int i=0;i<tmp4[2];i++)
+          {
+            int a=tmp2[2]*(partCompactFormat[2].first+i);
+            for(int j=0;j<tmp4[1];j++)
+              {
+                int b=tmp2[1]*(partCompactFormat[1].first+j);
+                for(int k=0;k<tmp4[0];k++,w++)
+                  {
+                    if(partCompactFormat[0].first+k+b+a!=*w)
+                      return false;
+                  }
+              }
+          }
+        return true;
+      }
+    case 2:
+      {
+        for(int j=0;j<tmp4[1];j++)
+          {
+            int b=tmp2[1]*(partCompactFormat[1].first+j);
+            for(int k=0;k<tmp4[0];k++,w++)
+              {
+                if(partCompactFormat[0].first+k+b!=*w)
+                  return false;
+              }
+          }
+        return true;
+      }
+    case 1:
+      {
+        for(int k=0;k<tmp4[0];k++,w++)
+          {
+            if(partCompactFormat[0].first+k!=*w)
+              return false;
+          }
+        return true;
+      }
+    default:
+      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::IsPartStructured : internal error !");
+    }
+}
+
+/*!
+ * This method builds the explicit entity array from the structure in \a st and the range in \a partCompactFormat.
+ *If the range contains invalid values regarding sructure an exception will be thrown.
+ *
+ * \return DataArrayInt * - a new object.
+ * \sa MEDCouplingStructuredMesh::IsPartStructured
+ */
+DataArrayInt *MEDCouplingStructuredMesh::BuildExplicitIdsFrom(const std::vector<int>& st, const std::vector< std::pair<int,int> >& partCompactFormat)
+{
+  if(st.size()!=partCompactFormat.size())
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::BuildExplicitIdsFrom : input arrays must have the same size !");
+  int nbOfItems(1);
+  std::vector<int> dims(st.size());
+  for(std::size_t i=0;i<st.size();i++)
+    {
+      if(partCompactFormat[i].first<0 || partCompactFormat[i].first>st[i])
+        throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::BuildExplicitIdsFrom : invalid input range 1 !");
+      if(partCompactFormat[i].second<0 || partCompactFormat[i].second>st[i])
+        throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::BuildExplicitIdsFrom : invalid input range 2 !");
+      if(partCompactFormat[i].second<=partCompactFormat[i].first)
+        throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::BuildExplicitIdsFrom : invalid input range 3 !");
+      dims[i]=partCompactFormat[i].second-partCompactFormat[i].first;
+      nbOfItems*=dims[i];
+    }
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret(DataArrayInt::New());
+  ret->alloc(nbOfItems,1);
+  int *pt(ret->getPointer());
+  switch(st.size())
+    {
+    case 3:
+      {
+        for(int i=0;i<dims[2];i++)
+          {
+            int a=(partCompactFormat[2].first+i)*st[0]*st[1];
+            for(int j=0;j<dims[1];j++)
+              {
+                int b=(partCompactFormat[1].first+j)*st[0];
+                for(int k=0;k<dims[0];k++,pt++)
+                  *pt=partCompactFormat[0].first+k+b+a;
+              }
+          }
+        break;
+      }
+    case 2:
+      {
+        for(int j=0;j<dims[1];j++)
+          {
+            int b=(partCompactFormat[1].first+j)*st[0];
+            for(int k=0;k<dims[0];k++,pt++)
+              *pt=partCompactFormat[0].first+k+b;
+          }
+        break;
+      }
+    case 1:
+      {
+        for(int k=0;k<dims[0];k++,pt++)
+          *pt=partCompactFormat[0].first+k;
+        break;
+      }
+    default:
+      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::BuildExplicitIdsFrom : Dimension supported are 1,2 or 3 !");
+    }
+  return ret.retn();
+}