From: geay <anthony.geay@cea.fr>
Date: Wed, 21 May 2014 15:42:23 +0000 (+0200)
Subject: First test OK with createPatchesFromCriterion
X-Git-Tag: V7_5_0a1~2^2~32^2~40
X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=dad156012f42a2e2eded91ac520c4bf6081ad5e7;p=tools%2Fmedcoupling.git

First test OK with createPatchesFromCriterion
---

diff --git a/src/MEDCoupling/MEDCouplingCartesianAMRMesh.cxx b/src/MEDCoupling/MEDCouplingCartesianAMRMesh.cxx
index 929adf7d6..d97d294cf 100644
--- a/src/MEDCoupling/MEDCouplingCartesianAMRMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingCartesianAMRMesh.cxx
@@ -19,11 +19,13 @@
 // Author : Anthony Geay
 
 #include "MEDCouplingCartesianAMRMesh.hxx"
+#include "MEDCoupling1GTUMesh.hxx"
 #include "MEDCouplingIMesh.hxx"
 #include "MEDCouplingUMesh.hxx"
 
 #include <limits>
 #include <sstream>
+#include <numeric>
 
 using namespace ParaMEDMEM;
 
@@ -179,81 +181,270 @@ public:
   int getNumberOfCells() const { return (int)_crit.size(); }
   void setNumberOfTrue(int nboft) { _nb_of_true=nboft; }
   std::vector<bool>& getCriterion() { return _crit; }
+  const std::vector<bool>& getConstCriterion() const { return _crit; }
+  void setPart(const std::vector< std::pair<int,int> >& part) { _part=part; }
   std::vector< std::pair<int,int> >& getPart() { return _part; }
   const std::vector< std::pair<int,int> >& getConstPart() const { return _part; }
   bool presenceOfTrue() const { return _nb_of_true>0; }
+  std::vector<int> computeCGS() const { return MEDCouplingStructuredMesh::GetDimensionsFromCompactFrmt(_part); }
+  std::vector< std::vector<int> > computeSignature() const { return MEDCouplingStructuredMesh::ComputeSignaturePerAxisOf(computeCGS(),getConstCriterion()); }
+  double getEfficiencyPerAxis(int axisId) const { return (double)_nb_of_true/((double)(_part[axisId].second-_part[axisId].first)); }
+  void zipToFitOnCriterion();
+  void updateNumberOfTrue() const;
+  MEDCouplingAutoRefCountObjectPtr<InternalPatch> extractPart(const std::vector< std::pair<int,int> >&partInGlobal) const;
+  MEDCouplingAutoRefCountObjectPtr<InternalPatch> deepCpy() const;
 protected:
   ~InternalPatch() { }
 private:
-  int _nb_of_true;
+  mutable int _nb_of_true;
   std::vector<bool> _crit;
+  //! _part is global
   std::vector< std::pair<int,int> > _part;
 };
 
-#if 0
-void dissectBigPatch (const Mesh& mesh, const Field& fieldFlag, const unsigned int minCellDirection,
-                      const unsigned int big_dims, const int dissect_direction, int cut[3] ) const
+void InternalPatch::zipToFitOnCriterion()
 {
-  int cut_found = 0 ;
-  int cut_place = -1 ;
-  float * ratio = NULL ;
-  float * ratio_inner = NULL ;
+  std::vector<int> cgs(computeCGS());
+  std::vector<bool> newCrit;
+  std::vector< std::pair<int,int> > newPart,newPart2;
+  int newNbOfTrue(MEDCouplingStructuredMesh::FindMinimalPartOf(cgs,_crit,newCrit,newPart));
+  MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt(_part,newPart,newPart2);
+  if(newNbOfTrue!=_nb_of_true)
+    throw INTERP_KERNEL::Exception("InternalPatch::zipToFitOnCrit : internal error !");
+  _crit=newCrit; _part=newPart2;
+}
+
+void InternalPatch::updateNumberOfTrue() const
+{
+  _nb_of_true=(int)std::count(_crit.begin(),_crit.end(),true);
+}
+
+MEDCouplingAutoRefCountObjectPtr<InternalPatch> InternalPatch::extractPart(const std::vector< std::pair<int,int> >&partInGlobal) const
+{
+  MEDCouplingAutoRefCountObjectPtr<InternalPatch> ret(new InternalPatch);
+  std::vector<int> cgs(computeCGS());
+  std::vector< std::pair<int,int> > newPart;
+  MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt(_part,partInGlobal,newPart);
+  MEDCouplingStructuredMesh::ExtractFieldOfBoolFrom(cgs,_crit,newPart,ret->getCriterion());
+  ret->setPart(partInGlobal);
+  ret->updateNumberOfTrue();
+  return ret;
+}
+
+MEDCouplingAutoRefCountObjectPtr<InternalPatch> InternalPatch::deepCpy() const
+{
+  MEDCouplingAutoRefCountObjectPtr<InternalPatch> ret(new InternalPatch);
+  (*ret)=*this;
+  return ret;
+}
 
-  ratio = new float [big_dims-1];
-  for(unsigned int id=0; id<big_dims-1; id++)
+void DissectBigPatch(const INTERP_KERNEL::BoxSplittingOptions& bso, const InternalPatch *patchToBeSplit, int axisId, int rangeOfAxisId, bool& cutFound, int& cutPlace)
+{
+  cutFound=false; cutPlace=-1;
+  std::vector<double> ratio(rangeOfAxisId-1);
+  for(int id=0;id<rangeOfAxisId-1;id++)
     {
-      float efficiency[2] ;
-      for(int h=0; h<2; h++)
+      double efficiency[2];
+      for(int h=0;h<2;h++)
         {
-          int rect_h[4] ;
-          copy(getIndexCorners(),getIndexCorners()+4,rect_h) ;
-          if (h == 0 )
-            rect_h[dissect_direction+2] = _indexCorners[dissect_direction]+id ;
-          else if ( h == 1)
-            rect_h[dissect_direction] =  _indexCorners[dissect_direction]+id+1;
-
-          Patch patch_h(rect_h);
-          patch_h.computeMesh(mesh);
-          patch_h.computeFieldFlag(fieldFlag);
-
-          int nb_cells_h ;
-          if ( dissect_direction == 0 )
-            nb_cells_h = patch_h.getNx() ;
+          std::vector< std::pair<int,int> > rectH(patchToBeSplit->getConstPart());
+          if(h==0)
+            rectH[axisId].second=patchToBeSplit->getConstPart()[axisId].first+id;
           else
-            nb_cells_h = patch_h.getNy() ;
+            rectH[axisId].first=patchToBeSplit->getConstPart()[axisId].first+id;
+          MEDCouplingAutoRefCountObjectPtr<InternalPatch> p(patchToBeSplit->deepCpy());
+          p->zipToFitOnCriterion();
+          //anouar rectH ?
+          efficiency[h]=p->getEfficiencyPerAxis(axisId);
+        }
+      ratio[id]=std::max(efficiency[0],efficiency[1])/std::min(efficiency[0],efficiency[1]);
+    }
+  int minCellDirection(bso.getMinCellDirection()),indexMin(-1);
+  int dimRatioInner(rangeOfAxisId-1-2*(minCellDirection-1));
+  std::vector<double > ratio_inner(dimRatioInner);
+  double minRatio(1.e10);
+  for(int i=0; i<dimRatioInner; i++)
+    {
+      if(ratio[minCellDirection-1+i]<minRatio)
+        {
+          minRatio=ratio[minCellDirection-1+i];
+          indexMin=i+minCellDirection;
+        }
+    }
+  cutFound=true; cutPlace=indexMin+patchToBeSplit->getConstPart()[axisId].first-1;
+}
 
-          int nb_cells_flag_h = patch_h.getNumberOfCellsFlags();
-          efficiency[h] = float (nb_cells_flag_h) / float(nb_cells_h) ;
+void FindHole(const INTERP_KERNEL::BoxSplittingOptions& bso, const InternalPatch *patchToBeSplit, const int axisId, bool& cutFound, int& cutPlace)
+{
+  cutPlace=-1; cutFound=false;
+  int minCellDirection(bso.getMinCellDirection());
+
+  int sortedDims[2];
+  sortedDims[0]=axisId==0?1:0;
+  sortedDims[1]=axisId==0?0:1;
+  static const int dim(2);
+  std::vector< std::vector<int> > signatures(patchToBeSplit->computeSignature());
+  for(int id=0;id<dim;id++)
+    {
+      const std::vector<int>& signature(signatures[sortedDims[id]]);
+      std::vector<int> hole;
+      std::vector<double> distance ;
+      int len((int)signature.size());
+      for(int i=0;i<len;i++)
+        if(signature[i]==0)
+          if(len>= 2*minCellDirection && i >= minCellDirection-1 && i <= len-minCellDirection-1)
+            hole.push_back(i);
+      if (hole.size()>0)
+        {
+          double center(((double)len/2.)+0.5);
+          for(std::size_t i=0;i<hole.size();i++)
+            distance.push_back(fabs(hole[i]+1+0.5-center));//anouar ! why 0.5 ?
+
+          double distanceMin=*std::min_element(distance.begin(),distance.end());
+          int posDistanceMin=std::find(distance.begin(),distance.end(),distanceMin)-distance.begin()-1;
+
+          cutFound=true;
+          cutPlace=hole[posDistanceMin]+patchToBeSplit->getConstPart()[axisId].first+1;
+          return ;
         }
-      ratio[id] = max(efficiency[0],efficiency[1])/
-          min(efficiency[0],efficiency[1]) ;
     }
+}
+
+void FindInflection(const INTERP_KERNEL::BoxSplittingOptions& bso, const InternalPatch *patchToBeSplit, bool& cutFound, int& cutPlace, int& axisId)
+{
+  cutFound=false; cutPlace=-1; axisId=-1;
 
-  int dim_ratio_inner = big_dims-1-2*(minCellDirection-1) ;
-  ratio_inner = new float [dim_ratio_inner];
-  float min_ratio = 1.E10 ;
-  int index_min = -1 ;
-  for(int i=0; i<dim_ratio_inner; i++)
+  const std::vector< std::pair<int,int> >& part(patchToBeSplit->getConstPart());
+  int sign,minCellDirection(bso.getMinCellDirection());
+  static const int dim = 2 ;
+
+  std::vector<int> zeroCrossDims(2,-1);
+  std::vector<int> zeroCrossVals(2,-1);
+  std::vector< std::vector<int> > signatures(patchToBeSplit->computeSignature());
+  for (int id=0;id<dim;id++)
     {
-      if ( ratio[minCellDirection-1+i] < min_ratio )
+      const std::vector<int>& signature(signatures[id]);
+
+      std::vector<int> derivate_second_order,gradient_absolute,signe_change,zero_cross,edge,max_cross_list ;
+      std::vector<double> distance ;
+
+      for (unsigned int i=1;i<signature.size()-1;i++)
+        derivate_second_order.push_back(signature[i-1]-2*signature[i]+signature[i+1]) ;
+
+      // Gradient absolute value
+      for ( unsigned int i=1;i<derivate_second_order.size();i++)
+        gradient_absolute.push_back(fabs(derivate_second_order[i]-derivate_second_order[i-1])) ;
+      for (unsigned int i=0;i<derivate_second_order.size()-1;i++)
         {
-          min_ratio = ratio[minCellDirection-1+i] ;
-          index_min = i+minCellDirection ;
+          if (derivate_second_order[i]*derivate_second_order[i+1] < 0 )
+            sign = -1 ;
+          if (derivate_second_order[i]*derivate_second_order[i+1] > 0 )
+            sign = 1 ;
+          if (derivate_second_order[i]*derivate_second_order[i+1] == 0 )
+            sign = 0 ;
+          if ( sign==0 || sign==-1 )
+            if ( i >= (unsigned int)minCellDirection-2 && i <= signature.size()-minCellDirection-2 )
+              {
+                zero_cross.push_back(i) ;
+                edge.push_back(gradient_absolute[i]) ;
+              }
+          signe_change.push_back(sign) ;
         }
+      if ( zero_cross.size() > 0 )
+        {
+          int max_cross=*max_element(edge.begin(),edge.end()) ;
+          for (unsigned int i=0;i<edge.size();i++)
+            if (edge[i]==max_cross)
+              max_cross_list.push_back(zero_cross[i]+1) ;
+
+          float center = (signature.size()/2.0)+0.5;
+          for (unsigned int i=0;i<max_cross_list.size();i++)
+            distance.push_back(fabs(max_cross_list[i]+1+0.5-center));
+
+          float distance_min=*min_element(distance.begin(),distance.end()) ;
+          int pos_distance_min=find(distance.begin(),distance.end(),distance_min)-distance.begin();
+          int best_place = max_cross_list[pos_distance_min] + part[id].first ;
+          if ( max_cross >=0 )
+            {
+              zeroCrossDims[id] = best_place ;
+              zeroCrossVals[id] = max_cross ;
+            }
+        }
+      derivate_second_order.clear() ;
+      gradient_absolute.clear() ;
+      signe_change.clear() ;
+      zero_cross.clear() ;
+      edge.clear() ;
+      max_cross_list.clear() ;
+      distance.clear() ;
     }
-  cut_found = 1 ;
-  cut_place = index_min + _indexCorners[dissect_direction] - 1 ;
-  cut[0] = cut_found ;
-  cut[1] = cut_place ;
-  cut[2] = dissect_direction ;
-  delete [] ratio ;
-  delete [] ratio_inner ;
-}
-#endif
+
+  if ( zeroCrossDims[0]!=-1 || zeroCrossDims[1]!=-1  )
+    {
+      int max_cross_dims = *max_element(zeroCrossVals.begin(),zeroCrossVals.end()) ;
+
+      if (zeroCrossVals[0]==max_cross_dims &&  zeroCrossVals[1]==max_cross_dims )
+        {
+          int nl_left(part[0].second-part[0].first);
+          int nc_left(part[1].second-part[1].first);
+          if ( nl_left >=  nc_left )
+            max_cross_dims = 0 ;
+          else
+            max_cross_dims = 1 ;
+        }
+      else
+        max_cross_dims=std::find(zeroCrossVals.begin(),zeroCrossVals.end(),max_cross_dims)-zeroCrossVals.begin();
+      cutFound=true;
+      cutPlace=zeroCrossDims[max_cross_dims];
+      axisId=max_cross_dims ;
+    }
+}
+
+void TryAction4(const INTERP_KERNEL::BoxSplittingOptions& bso, const InternalPatch *patchToBeSplit, int axisId, int rangeOfAxisId, bool& cutFound, int& cutPlace)
+{
+  cutFound=false;
+  if(patchToBeSplit->getEfficiency() <= bso.getEffeciencySnd())
+    {
+      if(rangeOfAxisId>=2*bso.getMinCellDirection())
+        {
+          cutFound=true;
+          cutPlace=rangeOfAxisId/2+patchToBeSplit->getConstPart()[axisId].first-1;
+        }
+    }
+  else
+    {
+      if(patchToBeSplit->getNumberOfCells()>bso.getMaxCells())
+        {
+          DissectBigPatch(bso,patchToBeSplit,axisId,rangeOfAxisId,cutFound,cutPlace);
+        }
+    }
+}
+
+MEDCouplingAutoRefCountObjectPtr<InternalPatch> DealWithNoCut(const InternalPatch *patch)
+{
+  MEDCouplingAutoRefCountObjectPtr<InternalPatch> ret(const_cast<InternalPatch *>(patch));
+  ret->incrRef();
+  return ret;
+}
+
+void DealWithCut(const InternalPatch *patchToBeSplit, int axisId, int cutPlace, std::vector<MEDCouplingAutoRefCountObjectPtr<InternalPatch> >& listOfPatches)
+{
+  MEDCouplingAutoRefCountObjectPtr<InternalPatch> leftPart,rightPart;
+  std::vector< std::pair<int,int> > rect(patchToBeSplit->getConstPart());
+  std::vector< std::pair<int,int> > leftRect(rect),rightRect(rect);
+  leftRect[axisId].second=cutPlace+1;
+  rightRect[axisId].first=cutPlace+1;
+  leftPart=patchToBeSplit->extractPart(leftRect);
+  rightPart=patchToBeSplit->extractPart(rightRect);
+  leftPart->zipToFitOnCriterion(); rightPart->zipToFitOnCriterion();
+  listOfPatches.push_back(leftPart);
+  listOfPatches.push_back(rightPart);
+}
+
 /// @endcond
 
 /*!
- * This method creates patches in \a this (by destroying the patches if any). This method uses \a criterion
+ * This method creates patches in \a this (by destroying the patches if any). This method uses \a criterion array as a field on cells on this level.
  */
 void MEDCouplingCartesianAMRMesh::createPatchesFromCriterion(const INTERP_KERNEL::BoxSplittingOptions& bso, const DataArrayByte *criterion, const std::vector<int>& factors)
 {
@@ -278,13 +469,22 @@ void MEDCouplingCartesianAMRMesh::createPatchesFromCriterion(const INTERP_KERNEL
       for(std::vector< MEDCouplingAutoRefCountObjectPtr<InternalPatch> >::iterator it=listOfPatches.begin();it!=listOfPatches.end();it++)
         {
           //
-          if((*it)->getEfficiency()>=bso.getEffeciency())
-            {
-              if((*it)->getNumberOfCells()>=bso.getMaxCells())
-                {
-
-                }
-            }
+          int axisId,rangeOfAxisId;
+          bool cutFound;
+          int cutPlace;
+          MEDCouplingStructuredMesh::FindTheWidestAxisOfGivenRangeInCompactFrmt((*it)->getConstPart(),axisId,rangeOfAxisId);
+          if((*it)->getEfficiency()>=bso.getEffeciency() && (*it)->getNumberOfCells()<bso.getMaxCells())
+            { listOfPatchesOK.push_back(DealWithNoCut(*it)); continue; }//action 1
+          FindHole(bso,*it,axisId,cutFound,cutPlace);
+          if(cutFound)
+            { DealWithCut(*it,axisId,cutPlace,listOfPatchesTmp); continue; }//action 2
+          FindInflection(bso,*it,cutFound,cutPlace,axisId);//axisId overwritten here if cutFound equal to true !
+          if(cutFound)
+            { DealWithCut(*it,axisId,cutPlace,listOfPatchesTmp); continue; }//action 3
+          TryAction4(bso,*it,axisId,rangeOfAxisId,cutFound,cutPlace);
+          if(cutFound)
+            { DealWithCut(*it,axisId,cutPlace,listOfPatchesTmp); continue; }//action 4
+          listOfPatchesOK.push_back(DealWithNoCut(*it));
         }
       listOfPatches=listOfPatchesTmp;
     }
@@ -338,6 +538,29 @@ MEDCouplingUMesh *MEDCouplingCartesianAMRMesh::buildUnstructured() const
   return MEDCouplingUMesh::MergeUMeshes(ms);
 }
 
+/*!
+ * This method returns a mesh containing as cells that there is patches at the current level.
+ * The patches are seen like 'boxes' that is too say the refinement will not appear here.
+ *
+ * \return MEDCoupling1SGTUMesh * - A new object to be managed by the caller containing as cells as there are patches in \a this.
+ */
+MEDCoupling1SGTUMesh *MEDCouplingCartesianAMRMesh::buildMeshFromPatchEnvelop() const
+{
+  std::vector<const MEDCoupling1SGTUMesh *> cells;
+  std::vector< MEDCouplingAutoRefCountObjectPtr<MEDCoupling1SGTUMesh> > cellsSafe;
+  for(std::vector< MEDCouplingAutoRefCountObjectPtr<MEDCouplingCartesianAMRPatch> >::const_iterator it=_patches.begin();it!=_patches.end();it++)
+    {
+      const MEDCouplingCartesianAMRPatch *patch(*it);
+      if(patch)
+        {
+          MEDCouplingAutoRefCountObjectPtr<MEDCouplingIMesh> cell(patch->getMesh()->getImageMesh()->asSingleCell());
+          MEDCouplingAutoRefCountObjectPtr<MEDCoupling1SGTUMesh> cell1SGT(cell->build1SGTUnstructured());
+          cellsSafe.push_back(cell1SGT); cells.push_back(cell1SGT);
+        }
+    }
+  return MEDCoupling1SGTUMesh::Merge1SGTUMeshes(cells);
+}
+
 MEDCouplingCartesianAMRMesh::MEDCouplingCartesianAMRMesh(const std::string& meshName, int spaceDim, const int *nodeStrctStart, const int *nodeStrctStop,
                                                          const double *originStart, const double *originStop, const double *dxyzStart, const double *dxyzStop):_father(0)
 {
diff --git a/src/MEDCoupling/MEDCouplingCartesianAMRMesh.hxx b/src/MEDCoupling/MEDCouplingCartesianAMRMesh.hxx
index 5f6309f48..d0ab4a421 100644
--- a/src/MEDCoupling/MEDCouplingCartesianAMRMesh.hxx
+++ b/src/MEDCoupling/MEDCouplingCartesianAMRMesh.hxx
@@ -34,6 +34,7 @@ namespace ParaMEDMEM
   class MEDCouplingIMesh;
   class MEDCouplingUMesh;
   class DataArrayByte;
+  class MEDCoupling1SGTUMesh;
   class MEDCouplingCartesianAMRMesh;
 
   /// @cond INTERNAL
@@ -77,6 +78,7 @@ namespace ParaMEDMEM
     MEDCOUPLING_EXPORT int getNumberOfCellsAtCurrentLevel() const;
     MEDCOUPLING_EXPORT int getNumberOfCellsRecursiveWithOverlap() const;
     MEDCOUPLING_EXPORT int getNumberOfCellsRecursiveWithoutOverlap() const;
+    MEDCOUPLING_EXPORT const MEDCouplingIMesh *getImageMesh() const { return _mesh; }
     //
     MEDCOUPLING_EXPORT const MEDCouplingCartesianAMRMesh *getFather() const;
     MEDCOUPLING_EXPORT const MEDCouplingCartesianAMRMesh *getGodFather() const;
@@ -88,6 +90,7 @@ namespace ParaMEDMEM
     MEDCOUPLING_EXPORT const MEDCouplingCartesianAMRPatch *getPatch(int patchId) const;
     //
     MEDCOUPLING_EXPORT MEDCouplingUMesh *buildUnstructured() const;
+    MEDCOUPLING_EXPORT MEDCoupling1SGTUMesh *buildMeshFromPatchEnvelop() const;
   private:
     MEDCouplingCartesianAMRMesh(const std::string& meshName, int spaceDim, const int *nodeStrctStart, const int *nodeStrctStop,
                                 const double *originStart, const double *originStop, const double *dxyzStart, const double *dxyzStop);
diff --git a/src/MEDCoupling/MEDCouplingIMesh.cxx b/src/MEDCoupling/MEDCouplingIMesh.cxx
index 142fac4b8..4b3da324a 100644
--- a/src/MEDCoupling/MEDCouplingIMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingIMesh.cxx
@@ -206,6 +206,36 @@ void MEDCouplingIMesh::refineWithFactor(const std::vector<int>& factors)
   declareAsNew();
 }
 
+/*!
+ * This method returns a newly created mesh containing a single cell in it. This returned cell covers exactly the space covered by \a this.
+ *
+ * \return MEDCouplingIMesh * - A newly created object (to be managed by the caller with decrRef) containing simply one cell.
+ *
+ * \throw if \a this does not pass the \c checkCoherency test.
+ */
+MEDCouplingIMesh *MEDCouplingIMesh::asSingleCell() const
+{
+  checkCoherency();
+  int spaceDim(getSpaceDimension()),nodeSt[3];
+  double dxyz[3];
+  for(int i=0;i<spaceDim;i++)
+    {
+      if(_structure[i]>=2)
+        {
+          nodeSt[i]=2;
+          dxyz[i]=(_structure[i]-1)*_dxyz[i];
+        }
+      else
+        {
+          nodeSt[i]=_structure[i];
+          dxyz[i]=_dxyz[i];
+        }
+    }
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingIMesh> ret(MEDCouplingIMesh::New(getName(),getSpaceDimension(),nodeSt,nodeSt+spaceDim,_origin,_origin+spaceDim,dxyz,dxyz+spaceDim));
+  ret->copyTinyInfoFrom(this);
+  return ret.retn();
+}
+
 /*!
  * This static method is useful to condense field on cells of a MEDCouplingIMesh instance coming from a refinement ( MEDCouplingIMesh::refineWithFactor for example)
  * to a coarse MEDCouplingIMesh instance. So this method can be seen as a specialization in P0P0 conservative interpolation non overlaping from fine image mesh
diff --git a/src/MEDCoupling/MEDCouplingIMesh.hxx b/src/MEDCoupling/MEDCouplingIMesh.hxx
index 896a7835d..ad6141254 100644
--- a/src/MEDCoupling/MEDCouplingIMesh.hxx
+++ b/src/MEDCoupling/MEDCouplingIMesh.hxx
@@ -47,6 +47,7 @@ namespace ParaMEDMEM
     MEDCOUPLING_EXPORT double getMeasureOfAnyCell() const;
     MEDCOUPLING_EXPORT MEDCouplingCMesh *convertToCartesian() const;
     MEDCOUPLING_EXPORT void refineWithFactor(const std::vector<int>& factors);
+    MEDCOUPLING_EXPORT MEDCouplingIMesh *asSingleCell() const;
     MEDCOUPLING_EXPORT static void CondenseFineToCoarse(DataArrayDouble *coarseDA, const std::vector<int>& coarseSt, const DataArrayDouble *fineDA, const std::vector< std::pair<int,int> >& fineLocInCoarse, const std::vector<int>& facts);
     MEDCOUPLING_EXPORT static void SpreadCoarseToFine(const DataArrayDouble *coarseDA, const std::vector<int>& coarseSt, DataArrayDouble *fineDA, const std::vector< std::pair<int,int> >& fineLocInCoarse, const std::vector<int>& facts);
     //
diff --git a/src/MEDCoupling/MEDCouplingStructuredMesh.cxx b/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
index 842cba3ed..19c054b6e 100644
--- a/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingStructuredMesh.cxx
@@ -739,26 +739,79 @@ int MEDCouplingStructuredMesh::FindMinimalPartOf(const std::vector<int>& st, con
 {
   if((int)crit.size()!=DeduceNumberOfGivenStructure(st))
     throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::FindMinimalPartOf : size of vector of boolean is invalid regarding the declared structure !");
+  int ret(-1);
   switch((int)st.size())
   {
     case 1:
       {
-        return FindMinimalPartOf1D(st,crit,reducedCrit,partCompactFormat);
+        ret=FindMinimalPartOf1D(st,crit,partCompactFormat);
         break;
       }
     case 2:
       {
-        return FindMinimalPartOf2D(st,crit,reducedCrit,partCompactFormat);
+        ret=FindMinimalPartOf2D(st,crit,partCompactFormat);
         break;
       }
     case 3:
       {
-        return FindMinimalPartOf3D(st,crit,reducedCrit,partCompactFormat);
+        ret=FindMinimalPartOf3D(st,crit,partCompactFormat);
         break;
       }
     default:
       throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::FindMinimalPartOf : only dimension 1, 2 and 3 are supported actually !");
   }
+  ExtractFieldOfBoolFrom(st,crit,partCompactFormat,reducedCrit);
+  return ret;
+}
+
+/*!
+ * This method is \b NOT wrapped in python.
+ * This method considers \a crit input parameter as a matrix having dimensions specified by \a st. This method returns for each axis
+ * the signature, that is to say the number of elems equal to true in \a crit along this axis.
+ */
+std::vector< std::vector<int> > MEDCouplingStructuredMesh::ComputeSignaturePerAxisOf(const std::vector<int>& st, const std::vector<bool>& crit)
+{
+  int dim((int)st.size());
+  std::vector< std::vector<int> > ret(dim);
+  switch(dim)
+  {
+    case 1:
+      {
+        int nx(st[0]);
+        ret[0].resize(nx);
+        std::vector<int>& retX(ret[0]);
+        for(int i=0;i<nx;i++)
+          retX[i]=crit[i]?1:0;
+        break;
+      }
+    case 2:
+      {
+        int nx(st[0]),ny(st[1]);
+        ret[0].resize(nx); ret[1].resize(ny);
+        std::vector<int>& retX(ret[0]);
+        for(int i=0;i<nx;i++)
+          {
+            int cnt(0);
+            for(int j=0;j<ny;j++)
+              if(crit[j*nx+i])
+                cnt++;
+            retX[i]=cnt;
+          }
+        std::vector<int>& retY(ret[1]);
+        for(int j=0;j<ny;j++)
+          {
+            int cnt(0);
+            for(int i=0;i<nx;i++)
+              if(crit[j*nx+i])
+                cnt++;
+            retY[j]=cnt;
+          }
+        break;
+      }
+    default:
+       throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::ComputeSignatureOf : only dimensions 1, 2 are supported !");
+  }
+  return ret;
 }
 
 DataArrayInt *MEDCouplingStructuredMesh::Build1GTNodalConnectivity1D(const int *nodeStBg)
@@ -849,7 +902,7 @@ DataArrayInt *MEDCouplingStructuredMesh::Build1GTNodalConnectivityOfSubLevelMesh
 /*!
  * \sa MEDCouplingStructuredMesh::FindMinimalPartOf
  */
-int MEDCouplingStructuredMesh::FindMinimalPartOf1D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat)
+int MEDCouplingStructuredMesh::FindMinimalPartOf1D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector< std::pair<int,int> >& partCompactFormat)
 {
   if(st.size()!=1)
     throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::FindMinimalPartOf1D : the input size of st must be equal to 1 !");
@@ -867,14 +920,13 @@ int MEDCouplingStructuredMesh::FindMinimalPartOf1D(const std::vector<int>& st, c
     return ret;
   partCompactFormat.resize(1);
   partCompactFormat[0].first=nxMin; partCompactFormat[0].second=nxMax+1;
-  ExtractVecOfBool(st,crit,partCompactFormat,reducedCrit);
   return ret;
 }
 
 /*!
  * \sa MEDCouplingStructuredMesh::FindMinimalPartOf
  */
-int MEDCouplingStructuredMesh::FindMinimalPartOf2D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat)
+int MEDCouplingStructuredMesh::FindMinimalPartOf2D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector< std::pair<int,int> >& partCompactFormat)
 {
   if(st.size()!=2)
     throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::FindMinimalPartOf2D : the input size of st must be equal to 2 !");
@@ -896,14 +948,13 @@ int MEDCouplingStructuredMesh::FindMinimalPartOf2D(const std::vector<int>& st, c
   partCompactFormat.resize(2);
   partCompactFormat[0].first=nxMin; partCompactFormat[0].second=nxMax+1;
   partCompactFormat[1].first=nyMin; partCompactFormat[1].second=nyMax+1;
-  ExtractVecOfBool(st,crit,partCompactFormat,reducedCrit);
   return ret;
 }
 
 /*!
  * \sa MEDCouplingStructuredMesh::FindMinimalPartOf
  */
-int MEDCouplingStructuredMesh::FindMinimalPartOf3D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat)
+int MEDCouplingStructuredMesh::FindMinimalPartOf3D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector< std::pair<int,int> >& partCompactFormat)
 {
   if(st.size()!=3)
     throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::FindMinimalPartOf3D : the input size of st must be equal to 3 !");
@@ -928,7 +979,6 @@ int MEDCouplingStructuredMesh::FindMinimalPartOf3D(const std::vector<int>& st, c
   partCompactFormat[0].first=nxMin; partCompactFormat[0].second=nxMax+1;
   partCompactFormat[1].first=nyMin; partCompactFormat[1].second=nyMax+1;
   partCompactFormat[2].first=nzMin; partCompactFormat[2].second=nzMax+1;
-  ExtractVecOfBool(st,crit,partCompactFormat,reducedCrit);
   return ret;
 }
 
@@ -1234,7 +1284,7 @@ std::vector<int> MEDCouplingStructuredMesh::GetDimensionsFromCompactFrmt(const s
  * \param [in] partCompactFormat The compact subpart to be enabled.
  * \param [in,out] vectToSwitchOn Vector which fetched items are enabled.
  *
- * \sa MEDCouplingStructuredMesh::BuildExplicitIdsFrom
+ * \sa MEDCouplingStructuredMesh::BuildExplicitIdsFrom, ExtractFieldOfBoolFrom
  */
 void MEDCouplingStructuredMesh::SwitchOnIdsFrom(const std::vector<int>& st, const std::vector< std::pair<int,int> >& partCompactFormat, std::vector<bool>& vectToSwitchOn)
 {
@@ -1276,16 +1326,144 @@ void MEDCouplingStructuredMesh::SwitchOnIdsFrom(const std::vector<int>& st, cons
         break;
       }
     default:
-      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::BuildExplicitIdsFrom : Dimension supported are 1,2 or 3 !");
+      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::SwitchOnIdsFrom : Dimension supported are 1,2 or 3 !");
+  }
+}
+
+/*!
+ * Obviously this method is \b NOT wrapped in python.
+ * This method is close to SwitchOnIdsFrom except that here, a sub field \a fieldOut is built starting from the input field \a fieldOfBool having the structure \a st.
+ * The extraction is defined by \a partCompactFormat.
+ *
+ * \param [in] st The entity structure.
+ * \param [in] fieldOfBool field of booleans having the size equal to \c MEDCouplingStructuredMesh::DeduceNumberOfGivenStructure(st).
+ * \param [in] partCompactFormat The compact subpart to be enabled.
+ * \param [out] fieldOut the result of the extraction.
+ *
+ * \sa MEDCouplingStructuredMesh::BuildExplicitIdsFrom, SwitchOnIdsFrom
+ */
+void MEDCouplingStructuredMesh::ExtractFieldOfBoolFrom(const std::vector<int>& st, const std::vector<bool>& fieldOfBool, const std::vector< std::pair<int,int> >& partCompactFormat, std::vector<bool>& fieldOut)
+{
+  if(st.size()!=partCompactFormat.size())
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::ExtractFieldOfBoolFrom : input arrays must have the same size !");
+  if((int)fieldOfBool.size()!=DeduceNumberOfGivenStructure(st))
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::ExtractFieldOfBoolFrom : invalid size of input field of boolean regarding the structure !");
+  std::vector<int> dims(GetDimensionsFromCompactFrmt(partCompactFormat));
+  int nbOfTuplesOfOutField(DeduceNumberOfGivenStructure(dims));
+  fieldOut.resize(nbOfTuplesOfOutField);
+  int it(0);
+  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++)
+                  fieldOut[it++]=fieldOfBool[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++)
+              fieldOut[it++]=fieldOfBool[partCompactFormat[0].first+k+b];
+          }
+        break;
+      }
+    case 1:
+      {
+        for(int k=0;k<dims[0];k++)
+          fieldOut[it++]=fieldOfBool[partCompactFormat[0].first+k];
+        break;
+      }
+    default:
+      throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::ExtractFieldOfBoolFrom : Dimension supported are 1,2 or 3 !");
   }
 }
 
+/*!
+ * This method changes the reference of a part of structured mesh \a partOfBigInAbs define in absolute reference to a new reference \a bigInAbs.
+ * So this method only performs a translation by doing \a partOfBigRelativeToBig = \a partOfBigInAbs - \a bigInAbs
+ * This method also checks that \a partOfBigInAbs is included in \a bigInAbs.
+ * This method is useful to extract a part from a field lying on a big mesh.
+ *
+ * \sa ChangeReferenceToGlobalOfCompactFrmt, BuildExplicitIdsFrom, SwitchOnIdsFrom, ExtractFieldOfBoolFrom
+ */
+void MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt(const std::vector< std::pair<int,int> >& bigInAbs, const std::vector< std::pair<int,int> >& partOfBigInAbs, std::vector< std::pair<int,int> >& partOfBigRelativeToBig)
+{
+  std::size_t dim(bigInAbs.size());
+  if(dim!=partOfBigInAbs.size())
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt : The size of parts (dimension) must be the same !");
+  partOfBigRelativeToBig.resize(dim);
+  for(std::size_t i=0;i<dim;i++)
+    {
+      if(bigInAbs[i].first>bigInAbs[i].second)
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt : Error at axis #" << i << " the input big part invalid, end before start !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
+      if(partOfBigInAbs[i].first<bigInAbs[i].first || partOfBigInAbs[i].first>=bigInAbs[i].second)
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt : Error at axis #" << i << " the part is not included in the big one (start) !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
+      partOfBigRelativeToBig[i].first=partOfBigInAbs[i].first-bigInAbs[i].first;
+      if(partOfBigInAbs[i].second<partOfBigInAbs[i].first || partOfBigInAbs[i].second>bigInAbs[i].second)
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt : Error at axis #" << i << " the part is not included in the big one (end) !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
+      partOfBigRelativeToBig[i].second=partOfBigInAbs[i].second-bigInAbs[i].first;
+    }
+}
+
+/*
+ * This method is performs the opposite reference modification than explained in ChangeReferenceFromGlobalOfCompactFrmt.
+ *
+ * \sa ChangeReferenceFromGlobalOfCompactFrmt
+ */
+void MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt(const std::vector< std::pair<int,int> >& bigInAbs, const std::vector< std::pair<int,int> >& partOfBigRelativeToBig, std::vector< std::pair<int,int> >& partOfBigInAbs)
+{
+  std::size_t dim(bigInAbs.size());
+  if(dim!=partOfBigRelativeToBig.size())
+    throw INTERP_KERNEL::Exception("MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt : The size of parts (dimension) must be the same !");
+  partOfBigInAbs.resize(dim);
+  for(std::size_t i=0;i<dim;i++)
+    {
+      if(bigInAbs[i].first>bigInAbs[i].second)
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt : Error at axis #" << i << " the input big part invalid, end before start !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
+      if(partOfBigRelativeToBig[i].first<0 || partOfBigRelativeToBig[i].first>=bigInAbs[i].second-bigInAbs[i].first)
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt : Error at axis #" << i << " the start of part is not in the big one !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
+      partOfBigInAbs[i].first=partOfBigRelativeToBig[i].first+bigInAbs[i].first;
+      if(partOfBigRelativeToBig[i].second<partOfBigRelativeToBig[i].first || partOfBigRelativeToBig[i].second>bigInAbs[i].second-bigInAbs[i].first)
+        {
+          std::ostringstream oss; oss << "MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt : Error at axis #" << i << " the end of part is not in the big one !";
+          throw INTERP_KERNEL::Exception(oss.str().c_str());
+        }
+      partOfBigInAbs[i].second=partOfBigRelativeToBig[i].second+bigInAbs[i].first;
+    }
+}
+
 /*!
  * 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, MEDCouplingStructuredMesh::DeduceNumberOfGivenRangeInCompactFrmt, SwitchOnIdsFrom
+ * \sa MEDCouplingStructuredMesh::IsPartStructured, MEDCouplingStructuredMesh::DeduceNumberOfGivenRangeInCompactFrmt, SwitchOnIdsFrom, ExtractFieldOfBoolFrom
  */
 DataArrayInt *MEDCouplingStructuredMesh::BuildExplicitIdsFrom(const std::vector<int>& st, const std::vector< std::pair<int,int> >& partCompactFormat)
 {
diff --git a/src/MEDCoupling/MEDCouplingStructuredMesh.hxx b/src/MEDCoupling/MEDCouplingStructuredMesh.hxx
index ef24a8546..1175ab37d 100644
--- a/src/MEDCoupling/MEDCouplingStructuredMesh.hxx
+++ b/src/MEDCoupling/MEDCouplingStructuredMesh.hxx
@@ -74,6 +74,9 @@ namespace ParaMEDMEM
     MEDCOUPLING_EXPORT static bool IsPartStructured(const int *startIds, const int *stopIds, const std::vector<int>& st, std::vector< std::pair<int,int> >& partCompactFormat);
     MEDCOUPLING_EXPORT static std::vector<int> GetDimensionsFromCompactFrmt(const std::vector< std::pair<int,int> >& partCompactFormat);
     MEDCOUPLING_EXPORT static void SwitchOnIdsFrom(const std::vector<int>& st, const std::vector< std::pair<int,int> >& partCompactFormat, std::vector<bool>& vectToSwitchOn);
+    MEDCOUPLING_EXPORT static void ExtractFieldOfBoolFrom(const std::vector<int>& st, const std::vector<bool>& fieldOfBool, const std::vector< std::pair<int,int> >& partCompactFormat, std::vector<bool>& fieldOut);
+    MEDCOUPLING_EXPORT static void ChangeReferenceFromGlobalOfCompactFrmt(const std::vector< std::pair<int,int> >& bigInAbs, const std::vector< std::pair<int,int> >& partOfBigInAbs, std::vector< std::pair<int,int> >& partOfBigRelativeToBig);
+    MEDCOUPLING_EXPORT static void ChangeReferenceToGlobalOfCompactFrmt(const std::vector< std::pair<int,int> >& bigInAbs, const std::vector< std::pair<int,int> >& partOfBigRelativeToBig, std::vector< std::pair<int,int> >& partOfBigInAbs);
     MEDCOUPLING_EXPORT static DataArrayInt *BuildExplicitIdsFrom(const std::vector<int>& st, const std::vector< std::pair<int,int> >& partCompactFormat);
     MEDCOUPLING_EXPORT static DataArrayInt *Build1GTNodalConnectivity(const int *nodeStBg, const int *nodeStEnd);
     MEDCOUPLING_EXPORT static DataArrayInt *Build1GTNodalConnectivityOfSubLevelMesh(const int *nodeStBg, const int *nodeStEnd);
@@ -81,6 +84,7 @@ namespace ParaMEDMEM
     MEDCOUPLING_EXPORT static int DeduceNumberOfGivenStructure(const std::vector<int>& st);
     MEDCOUPLING_EXPORT static void FindTheWidestAxisOfGivenRangeInCompactFrmt(const std::vector< std::pair<int,int> >& partCompactFormat, int& axisId, int& sizeOfRange);
     MEDCOUPLING_EXPORT static int FindMinimalPartOf(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat);
+    MEDCOUPLING_EXPORT static std::vector< std::vector<int> > ComputeSignaturePerAxisOf(const std::vector<int>& st, const std::vector<bool>& crit);
   private:
     static int GetNumberOfCellsOfSubLevelMesh(const std::vector<int>& cgs, int mdim);
     static void GetReverseNodalConnectivity1(const std::vector<int>& ngs, DataArrayInt *revNodal, DataArrayInt *revNodalIndx);
@@ -91,9 +95,9 @@ namespace ParaMEDMEM
     static DataArrayInt *Build1GTNodalConnectivity3D(const int *nodeStBg);
     static DataArrayInt *Build1GTNodalConnectivityOfSubLevelMesh2D(const int *nodeStBg);
     static DataArrayInt *Build1GTNodalConnectivityOfSubLevelMesh3D(const int *nodeStBg);
-    static int FindMinimalPartOf1D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat);
-    static int FindMinimalPartOf2D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat);
-    static int FindMinimalPartOf3D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector<bool>& reducedCrit, std::vector< std::pair<int,int> >& partCompactFormat);
+    static int FindMinimalPartOf1D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector< std::pair<int,int> >& partCompactFormat);
+    static int FindMinimalPartOf2D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector< std::pair<int,int> >& partCompactFormat);
+    static int FindMinimalPartOf3D(const std::vector<int>& st, const std::vector<bool>& crit, std::vector< std::pair<int,int> >& partCompactFormat);
     static void ExtractVecOfBool(const std::vector<int>& st, const std::vector<bool>& crit, const std::vector< std::pair<int,int> >& partCompactFormat, std::vector<bool>& reducedCrit);
   protected:
     static int ZipNodeStructure(const int *nodeStBg, const int *nodeStEnd, int zipNodeSt[3]);
diff --git a/src/MEDCoupling_Swig/MEDCouplingBasicsTest.py b/src/MEDCoupling_Swig/MEDCouplingBasicsTest.py
index c9e409eda..530995096 100644
--- a/src/MEDCoupling_Swig/MEDCouplingBasicsTest.py
+++ b/src/MEDCoupling_Swig/MEDCouplingBasicsTest.py
@@ -15105,8 +15105,8 @@ class MEDCouplingBasicsTest(unittest.TestCase):
         fine=DataArrayDouble(3*2*3*4*4*4) ; fine.iota(0) #X=3,Y=2,Z=3 refined by 4
         MEDCouplingIMesh.SpreadCoarseToFine(coarse,[5,7,5],fine,[(1,4),(2,4),(1,4)],[4,4,4])
         self.assertTrue(fine.isEqual(DataArrayDouble([46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,46.,46.,46.,46.,47.,47.,47.,47.,48.,48.,48.,48.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,51.,51.,51.,51.,52.,52.,52.,52.,53.,53.,53.,53.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,81.,81.,81.,81.,82.,82.,82.,82.,83.,83.,83.,83.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,86.,86.,86.,86.,87.,87.,87.,87.,88.,88.,88.,88.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,116.,116.,116.,116.,117.,117.,117.,117.,118.,118.,118.,118.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.,121.,121.,121.,121.,122.,122.,122.,122.,123.,123.,123.,123.]),1e-12))
-        #f=MEDCouplingFieldDouble(ON_CELLS) ; f.setMesh(MEDCouplingIMesh("",3,DataArrayInt([6,8,6]),[0.,0.,0.],DataArrayDouble((1.,1.,1.)))) ; f.setArray(coarse) ; f.setName("tutu") ; f.checkCoherency() ; f.writeVTK("coarse.vti")
-        #f=MEDCouplingFieldDouble(ON_CELLS) ; f.setMesh(MEDCouplingIMesh("",3,DataArrayInt([13,9,13]),[1.,2.,1.],DataArrayDouble((0.25,0.25,0.25)))) ; f.setArray(fine) ; f.setName("tutu") ; f.checkCoherency() ; f.writeVTK("fine.vti")
+        f=MEDCouplingFieldDouble(ON_CELLS) ; f.setMesh(MEDCouplingIMesh("",3,DataArrayInt([6,8,6]),[0.,0.,0.],DataArrayDouble((1.,1.,1.)))) ; f.setArray(coarse) ; f.setName("tutu") ; f.checkCoherency()
+        f=MEDCouplingFieldDouble(ON_CELLS) ; f.setMesh(MEDCouplingIMesh("",3,DataArrayInt([13,9,13]),[1.,2.,1.],DataArrayDouble((0.25,0.25,0.25)))) ; f.setArray(fine) ; f.setName("tutu") ; f.checkCoherency()
         # 1D
         coarse=DataArrayDouble(5) ; coarse.iota(0) #X=5
         fine=DataArrayDouble(3*4) ; fine.iota(0) #X=3 refined by 4
@@ -15114,6 +15114,30 @@ class MEDCouplingBasicsTest(unittest.TestCase):
         self.assertTrue(fine.isEqual(DataArrayDouble([1.,1.,1.,1.,2.,2.,2.,2.,3.,3.,3.,3.]),1e-12))
         pass
 
+    def testAMR4(self):
+        """This test focuses on MEDCouplingCartesianAMRMesh.createPatchesFromCriterion method. To test it a field containing 0 everywhere except in the annulus (centered on the center of the mesh) value is 1."""
+        im=MEDCouplingIMesh("mesh",2,[51,51],[0.,0.],[0.04,0.04])
+        b=im.getBarycenterAndOwner() ; b-=[1.,1.] ; b=b.magnitude()
+        ids=b.getIdsInRange(0.4,0.7)
+        f=MEDCouplingFieldDouble(ON_CELLS) ; f.setMesh(im) ; f.setName("toto") ; arr=DataArrayDouble(im.getNumberOfCells()) ; arr[:]=0. ; arr[ids]=1. ; f.setArray(arr)
+        # f.write("test.vti")
+        amr=MEDCouplingCartesianAMRMesh("mesh",2,[51,51],[0.,0.],[0.04,0.04])
+        arr2=DataArrayByte(im.getNumberOfCells()) ; arr2[:]=0 ; arr2[ids]=1
+        bso=BoxSplittingOptions() ; bso.setEffeciency(0.8) ; bso.setEffeciencySnd(0.8) ; bso.setMaxCells(1000) ; bso.setMinCellDirection(3)
+        amr.createPatchesFromCriterion(bso,arr2,[2,2])
+        self.assertEqual(18,amr.getNumberOfPatches())
+        exp0=[[(8,14),(19,38)],[(19,31),(8,17)],[(19,31),(33,42)],[(10,14),(12,16)],[(9,14),(16,19)],[(14,19),(9,19)],[(14,17),(19,22)],[(14,19),(31,41)],[(36,42),(19,38)],[(14,15),(22,28)],[(14,17),(28,31)],[(31,36),(9,19)],[(33,36),(19,22)],[(31,36),(31,41)],[(36,40),(12,16)],[(36,41),(16,19)],[(35,36),(22,28)],[(33,36),(28,31)]]
+        for i,bltr in enumerate(exp0):
+            self.assertEqual(amr[i].getBLTRRange(),bltr)
+            pass
+        m=amr.buildMeshFromPatchEnvelop()
+        self.assertTrue(m.getNodalConnectivity().isEqual(DataArrayInt([1,0,2,3,5,4,6,7,9,8,10,11,13,12,14,15,17,16,18,19,21,20,22,23,25,24,26,27,29,28,30,31,33,32,34,35,37,36,38,39,41,40,42,43,45,44,46,47,49,48,50,51,53,52,54,55,57,56,58,59,61,60,62,63,65,64,66,67,69,68,70,71])))
+        self.assertTrue(m.getCoords().isEqualWithoutConsideringStr(DataArrayDouble([0.32,0.76,0.56,0.76,0.32,1.52,0.56,1.52,0.76,0.32,1.24,0.32,0.76,0.68,1.24,0.68,0.76,1.32,1.24,1.32,0.76,1.68,1.24,1.68,0.4,0.48,0.56,0.48,0.4,0.64,0.56,0.64,0.36,0.64,0.56,0.64,0.36,0.76,0.56,0.76,0.56,0.36,0.76,0.36,0.56,0.76,0.76,0.76,0.56,0.76,0.68,0.76,0.56,0.88,0.68,0.88,0.56,1.24,0.76,1.24,0.56,1.64,0.76,1.64,1.44,0.76,1.68,0.76,1.44,1.52,1.68,1.52,0.56,0.88,0.6,0.88,0.56,1.12,0.6,1.12,0.56,1.12,0.68,1.12,0.56,1.24,0.68,1.24,1.24,0.36,1.44,0.36,1.24,0.76,1.44,0.76,1.32,0.76,1.44,0.76,1.32,0.88,1.44,0.88,1.24,1.24,1.44,1.24,1.24,1.64,1.44,1.64,1.44,0.48,1.6,0.48,1.44,0.64,1.6,0.64,1.44,0.64,1.64,0.64,1.44,0.76,1.64,0.76,1.4,0.88,1.44,0.88,1.4,1.12,1.44,1.12,1.32,1.12,1.44,1.12,1.32,1.24,1.44,1.24],72,2),1e-12))
+        #
+        self.assertEqual(MEDCouplingStructuredMesh.ChangeReferenceToGlobalOfCompactFrmt([(8,32),(4,17)],[(0,24),(2,12)]),[(8,32),(6,16)])
+        self.assertEqual(MEDCouplingStructuredMesh.ChangeReferenceFromGlobalOfCompactFrmt([(8,32),(4,17)],[(8,32),(6,16)]),[(0,24),(2,12)])
+        pass
+
     def setUp(self):
         pass
     pass
diff --git a/src/MEDCoupling_Swig/MEDCouplingCommon.i b/src/MEDCoupling_Swig/MEDCouplingCommon.i
index 4c1ba6391..cc6307736 100644
--- a/src/MEDCoupling_Swig/MEDCouplingCommon.i
+++ b/src/MEDCoupling_Swig/MEDCouplingCommon.i
@@ -306,6 +306,7 @@ using namespace INTERP_KERNEL;
 %newobject ParaMEDMEM::MEDCouplingCMesh::clone;
 %newobject ParaMEDMEM::MEDCouplingCMesh::getCoordsAt;
 %newobject ParaMEDMEM::MEDCouplingIMesh::New;
+%newobject ParaMEDMEM::MEDCouplingIMesh::asSingleCell;
 %newobject ParaMEDMEM::MEDCouplingIMesh::convertToCartesian;
 %newobject ParaMEDMEM::MEDCouplingCurveLinearMesh::New;
 %newobject ParaMEDMEM::MEDCouplingCurveLinearMesh::clone;
@@ -317,6 +318,8 @@ using namespace INTERP_KERNEL;
 %newobject ParaMEDMEM::MEDCouplingCartesianAMRPatch::__getitem__;
 %newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::New;
 %newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::buildUnstructured;
+%newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::buildMeshFromPatchEnvelop;
+%newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::getImageMesh;
 %newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::getGodFather;
 %newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::getFather;
 %newobject ParaMEDMEM::MEDCouplingCartesianAMRMesh::getPatch;
@@ -389,6 +392,13 @@ namespace INTERP_KERNEL
     void setMaxCells(int maxCells) throw(INTERP_KERNEL::Exception);
     void copyOptions(const BoxSplittingOptions & other) throw(INTERP_KERNEL::Exception);
     std::string printOptions() const throw(INTERP_KERNEL::Exception);
+    %extend
+    {
+      std::string __str__() const throw(INTERP_KERNEL::Exception)
+      {
+        return self->printOptions();
+      }
+    }
   };
 }
 
@@ -2911,6 +2921,40 @@ namespace ParaMEDMEM
         PyTuple_SetItem(ret,1,ret1Py);
         return ret;
       }
+
+      static PyObject *ChangeReferenceFromGlobalOfCompactFrmt(PyObject *bigInAbs, PyObject *partOfBigInAbs) throw(INTERP_KERNEL::Exception)
+      {
+        std::vector< std::pair<int,int> > param0,param1,ret;
+        convertPyToVectorPairInt(bigInAbs,param0);
+        convertPyToVectorPairInt(partOfBigInAbs,param1);
+        MEDCouplingStructuredMesh::ChangeReferenceFromGlobalOfCompactFrmt(param0,param1,ret);
+        PyObject *retPy(PyList_New(ret.size()));
+        for(std::size_t i=0;i<ret.size();i++)
+          {
+            PyObject *tmp(PyTuple_New(2));
+            PyTuple_SetItem(tmp,0,PyInt_FromLong(ret[i].first));
+            PyTuple_SetItem(tmp,1,PyInt_FromLong(ret[i].second));
+            PyList_SetItem(retPy,i,tmp);
+          }
+        return retPy;
+      }
+
+      static PyObject *ChangeReferenceToGlobalOfCompactFrmt(PyObject *bigInAbs, PyObject *partOfBigRelativeToBig) throw(INTERP_KERNEL::Exception)
+      {
+        std::vector< std::pair<int,int> > param0,param1,ret;
+        convertPyToVectorPairInt(bigInAbs,param0);
+        convertPyToVectorPairInt(partOfBigRelativeToBig,param1);
+        MEDCouplingStructuredMesh::ChangeReferenceToGlobalOfCompactFrmt(param0,param1,ret);
+        PyObject *retPy(PyList_New(ret.size()));
+        for(std::size_t i=0;i<ret.size();i++)
+          {
+            PyObject *tmp(PyTuple_New(2));
+            PyTuple_SetItem(tmp,0,PyInt_FromLong(ret[i].first));
+            PyTuple_SetItem(tmp,1,PyInt_FromLong(ret[i].second));
+            PyList_SetItem(retPy,i,tmp);
+          }
+        return retPy;
+      }
     }
   };
 
@@ -3020,6 +3064,7 @@ namespace ParaMEDMEM
     double getMeasureOfAnyCell() const throw(INTERP_KERNEL::Exception);
     MEDCouplingCMesh *convertToCartesian() const throw(INTERP_KERNEL::Exception);
     void refineWithFactor(const std::vector<int>& factors) throw(INTERP_KERNEL::Exception);
+    MEDCouplingIMesh *asSingleCell() const throw(INTERP_KERNEL::Exception);
     %extend
     {
       MEDCouplingIMesh()
@@ -4712,8 +4757,10 @@ namespace ParaMEDMEM
     //
     int getNumberOfPatches() const throw(INTERP_KERNEL::Exception);    
     MEDCouplingUMesh *buildUnstructured() const throw(INTERP_KERNEL::Exception);
+    MEDCoupling1SGTUMesh *buildMeshFromPatchEnvelop() const throw(INTERP_KERNEL::Exception);
     void removePatch(int patchId) throw(INTERP_KERNEL::Exception);
     void detachFromFather() throw(INTERP_KERNEL::Exception);
+    void createPatchesFromCriterion(const INTERP_KERNEL::BoxSplittingOptions& bso, const DataArrayByte *criterion, const std::vector<int>& factors) throw(INTERP_KERNEL::Exception);
     %extend
     {
       static MEDCouplingCartesianAMRMesh *New(const std::string& meshName, int spaceDim, PyObject *nodeStrct, PyObject *origin, PyObject *dxyz) throw(INTERP_KERNEL::Exception)
@@ -4771,6 +4818,14 @@ namespace ParaMEDMEM
         return ret;
       }
 
+      MEDCouplingIMesh *getImageMesh() const throw(INTERP_KERNEL::Exception)
+      {
+        const MEDCouplingIMesh *ret(self->getImageMesh());
+        if(ret)
+          ret->incrRef();
+        return const_cast<MEDCouplingIMesh *>(ret);
+      }
+
       MEDCouplingCartesianAMRPatch *__getitem__(int patchId) const throw(INTERP_KERNEL::Exception)
       {
         if(patchId==self->getNumberOfPatches())
diff --git a/src/MEDCoupling_Swig/MEDCouplingRemapperTest.py b/src/MEDCoupling_Swig/MEDCouplingRemapperTest.py
index 9974af73d..72f92c59e 100644
--- a/src/MEDCoupling_Swig/MEDCouplingRemapperTest.py
+++ b/src/MEDCoupling_Swig/MEDCouplingRemapperTest.py
@@ -765,11 +765,11 @@ class MEDCouplingBasicsTest(unittest.TestCase):
         """ This test is the origin of the ref values for MEDCouplingBasicsTest.testAMR2"""
         coarse=DataArrayDouble(35) ; coarse.iota(0) #X=5,Y=7
         fine=DataArrayDouble(3*2*4*4) ; fine.iota(0) #X=3,Y=2 refined by 4
-        MEDCouplingIMesh.CondenseFineToCoarse(coarse,[5,7],fine,[(1,4),(2,4)])
+        MEDCouplingIMesh.CondenseFineToCoarse(coarse,[5,7],fine,[(1,4),(2,4)],[4,4])
         #
         m=MEDCouplingCartesianAMRMesh("mesh",2,[6,8],[0.,0.],[1.,1.])
         trgMesh=m.buildUnstructured()
-        m.addPatch([(1,4),(2,4)],4)
+        m.addPatch([(1,4),(2,4)],[4,4])
         srcMesh=m[0].getMesh().buildUnstructured()
         srcField=MEDCouplingFieldDouble(ON_CELLS)
         fine2=DataArrayDouble(3*2*4*4) ; fine2.iota(0) ; srcField.setArray(fine2)