From: ageay <ageay>
Date: Thu, 11 Apr 2013 13:26:29 +0000 (+0000)
Subject: MEDCouplingFieldDouble::buildSubPartRange
X-Git-Tag: V6_main_FINAL~158
X-Git-Url: http://git.salome-platform.org/gitweb/?a=commitdiff_plain;h=d002061cf33d5731aa8cc02415ceacffc580b1ad;p=tools%2Fmedcoupling.git

MEDCouplingFieldDouble::buildSubPartRange
---

diff --git a/src/MEDCoupling/MEDCouplingField.cxx b/src/MEDCoupling/MEDCouplingField.cxx
index 4f3fc3e56..967caf414 100644
--- a/src/MEDCoupling/MEDCouplingField.cxx
+++ b/src/MEDCoupling/MEDCouplingField.cxx
@@ -394,7 +394,9 @@ MEDCouplingField::MEDCouplingField(const MEDCouplingField& other, bool deepCopy)
 
 /*!
  * This method returns a submesh of 'mesh' instance constituting cell ids contained in array defined as an interval [start;end).
- * @param di is an array returned that specifies entity ids (nodes, cells ids...) in mesh 'mesh' of entity in returned submesh.
+ * @param di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array.
+ * 
+ * \sa MEDCouplingField::buildSubMeshDataRange
  */
 MEDCouplingMesh *MEDCouplingField::buildSubMeshData(const int *start, const int *end, DataArrayInt *&di) const
 {
@@ -403,6 +405,23 @@ MEDCouplingMesh *MEDCouplingField::buildSubMeshData(const int *start, const int
   return _type->buildSubMeshData(_mesh,start,end,di);
 }
 
+/*!
+ * This method returns a submesh of 'mesh' instance constituting cell ids defined by a range given by the 3 following inputs \a begin, \a end and \a step.
+ * 
+ * \param [out] beginOut Valid only if \a di is NULL
+ * \param [out] endOut Valid only if \a di is NULL
+ * \param [out] stepOut Valid only if \a di is NULL
+ * \param [out] di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array if no output range is foundable.
+ * 
+ * \sa MEDCouplingField::buildSubMeshData
+ */
+MEDCouplingMesh *MEDCouplingField::buildSubMeshDataRange(int begin, int end, int step, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const
+{
+  if(!((const MEDCouplingFieldDiscretization *)_type))
+    throw INTERP_KERNEL::Exception("Spatial discretization not set ! Impossible to call buildSubMeshDataRange method !");
+  return _type->buildSubMeshDataRange(_mesh,begin,end,step,beginOut,endOut,stepOut,di);
+}
+
 /*!
  * This method returns tuples ids implied by the mesh selection of the  cell ids contained in array defined as an interval [start;end).
  * \return a newly allocated DataArrayInt instance containing tuples ids.
diff --git a/src/MEDCoupling/MEDCouplingField.hxx b/src/MEDCoupling/MEDCouplingField.hxx
index 1df5494c2..ed37178f7 100644
--- a/src/MEDCoupling/MEDCouplingField.hxx
+++ b/src/MEDCoupling/MEDCouplingField.hxx
@@ -63,6 +63,7 @@ namespace ParaMEDMEM
     DataArrayDouble *getLocalizationOfDiscr() const throw(INTERP_KERNEL::Exception);
     MEDCouplingFieldDouble *buildMeasureField(bool isAbs) const throw(INTERP_KERNEL::Exception);
     MEDCouplingMesh *buildSubMeshData(const int *start, const int *end, DataArrayInt *&di) const;
+    MEDCouplingMesh *buildSubMeshDataRange(int begin, int end, int step, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const;
     DataArrayInt *computeTupleIdsToSelectFromCellIds(const int *startCellIds, const int *endCellIds) const;
     const MEDCouplingFieldDiscretization *getDiscretization() const { return _type; }
     MEDCouplingFieldDiscretization *getDiscretization() { return _type; }
diff --git a/src/MEDCoupling/MEDCouplingFieldDiscretization.cxx b/src/MEDCoupling/MEDCouplingFieldDiscretization.cxx
index f9e201fac..4cedfe1a0 100644
--- a/src/MEDCoupling/MEDCouplingFieldDiscretization.cxx
+++ b/src/MEDCoupling/MEDCouplingFieldDiscretization.cxx
@@ -164,6 +164,14 @@ MEDCouplingFieldDiscretization *MEDCouplingFieldDiscretization::clonePart(const
   return clone();
 }
 
+/*!
+ * For all field discretization excepted GaussPts the slice( \a beginCellId, \a endCellIds, \a stepCellId ) has no impact on the cloned instance.
+ */
+MEDCouplingFieldDiscretization *MEDCouplingFieldDiscretization::clonePartRange(int beginCellIds, int endCellIds, int stepCellIds) const
+{
+  return clone();
+}
+
 /*!
  * Excepted for MEDCouplingFieldDiscretizationPerCell no underlying TimeLabel object : nothing to do in generally.
  */
@@ -256,6 +264,22 @@ void MEDCouplingFieldDiscretization::integral(const MEDCouplingMesh *mesh, const
     }
 }
 
+/*!
+ * This method is strictly equivalent to MEDCouplingFieldDiscretization::buildSubMeshData except that it is optimized for input defined as a range of cell ids.
+ * 
+ * \param [out] beginOut Valid only if \a di is NULL
+ * \param [out] endOut Valid only if \a di is NULL
+ * \param [out] stepOut Valid only if \a di is NULL
+ * \param [out] di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array if no output range is foundable.
+ *
+ * \sa MEDCouplingFieldDiscretization::buildSubMeshData
+ */
+MEDCouplingMesh *MEDCouplingFieldDiscretization::buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const
+{
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> da=DataArrayInt::Range(beginCellIds,endCellIds,stepCellIds);
+  return buildSubMeshData(mesh,da->begin(),da->end(),di);
+}
+
 void MEDCouplingFieldDiscretization::getSerializationIntArray(DataArrayInt *& arr) const
 {
   arr=0;
@@ -619,17 +643,38 @@ DataArrayInt *MEDCouplingFieldDiscretizationP0::computeTupleIdsToSelectFromCellI
  * This method returns a submesh of 'mesh' instance constituting cell ids contained in array defined as an interval [start;end).
  * @param di is an array returned that specifies entity ids (here cells ids) in mesh 'mesh' of entity in returned submesh.
  * Example : The first cell id of returned mesh has the (*di)[0] id in 'mesh'
+ *
+ * \sa MEDCouplingFieldDiscretizationP0::buildSubMeshDataRange
  */
 MEDCouplingMesh *MEDCouplingFieldDiscretizationP0::buildSubMeshData(const MEDCouplingMesh *mesh, const int *start, const int *end, DataArrayInt *&di) const
 {
   if(!mesh)
     throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationP0::buildSubMeshData : NULL input mesh !");
-  MEDCouplingMesh *ret=mesh->buildPart(start,end);
-  di=DataArrayInt::New();
-  di->alloc((int)std::distance(start,end),1);
-  int *pt=di->getPointer();
-  std::copy(start,end,pt);
-  return ret;
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPart(start,end);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> diSafe=DataArrayInt::New();
+  diSafe->alloc((int)std::distance(start,end),1);
+  std::copy(start,end,diSafe->getPointer());
+  di=diSafe.retn();
+  return ret.retn();
+}
+
+/*!
+ * This method is strictly equivalent to MEDCouplingFieldDiscretizationP0::buildSubMeshData except that it is optimized for input defined as a range of cell ids.
+ * 
+ * \param [out] beginOut Valid only if \a di is NULL
+ * \param [out] endOut Valid only if \a di is NULL
+ * \param [out] stepOut Valid only if \a di is NULL
+ * \param [out] di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array if no output range is foundable.
+ *
+ * \sa MEDCouplingFieldDiscretizationP0::buildSubMeshData
+ */
+MEDCouplingMesh *MEDCouplingFieldDiscretizationP0::buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const
+{
+  if(!mesh)
+    throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationP0::buildSubMeshDataRange : NULL input mesh !");
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPartRange(beginCellIds,endCellIds,stepCellIds);
+  di=0; beginOut=beginCellIds; endOut=endCellIds; stepOut=stepCellIds;
+  return ret.retn();
 }
 
 int MEDCouplingFieldDiscretizationOnNodes::getNumberOfTuples(const MEDCouplingMesh *mesh) const throw(INTERP_KERNEL::Exception)
@@ -709,11 +754,34 @@ MEDCouplingMesh *MEDCouplingFieldDiscretizationOnNodes::buildSubMeshData(const M
 {
   if(!mesh)
     throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationNodes::buildSubMeshData : NULL input mesh !");
-  MEDCouplingMesh *ret=mesh->buildPartAndReduceNodes(start,end,di);
-  DataArrayInt *di2=di->invertArrayO2N2N2O(ret->getNumberOfNodes());
-  di->decrRef();
-  di=di2;
-  return ret;
+  DataArrayInt *diTmp=0;
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPartAndReduceNodes(start,end,diTmp);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> diTmpSafe(diTmp);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> di2=diTmpSafe->invertArrayO2N2N2O(ret->getNumberOfNodes());
+  di=di2.retn();
+  return ret.retn();
+}
+
+/*!
+ * This method is strictly equivalent to MEDCouplingFieldDiscretizationNodes::buildSubMeshData except that it is optimized for input defined as a range of cell ids.
+ * 
+ * \param [out] beginOut Valid only if \a di is NULL
+ * \param [out] endOut Valid only if \a di is NULL
+ * \param [out] stepOut Valid only if \a di is NULL
+ * \param [out] di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array if no output range is foundable.
+ *
+ * \sa MEDCouplingFieldDiscretizationNodes::buildSubMeshData
+ */
+MEDCouplingMesh *MEDCouplingFieldDiscretizationOnNodes::buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const
+{
+  if(!mesh)
+    throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationOnNodes::buildSubMeshDataRange : NULL input mesh !");
+  DataArrayInt *diTmp=0;
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPartRangeAndReduceNodes(beginCellIds,endCellIds,stepCellIds,beginOut,endOut,stepOut,diTmp);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> diTmpSafe(diTmp);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> di2=diTmpSafe->invertArrayO2N2N2O(ret->getNumberOfNodes());
+  di=di2.retn();
+  return ret.retn();
 }
 
 /*!
@@ -911,6 +979,15 @@ MEDCouplingFieldDiscretizationPerCell::MEDCouplingFieldDiscretizationPerCell(con
     }
 }
 
+MEDCouplingFieldDiscretizationPerCell::MEDCouplingFieldDiscretizationPerCell(const MEDCouplingFieldDiscretizationPerCell& other, int beginCellIds, int endCellIds, int stepCellIds):_discr_per_cell(0)
+{
+  DataArrayInt *arr=other._discr_per_cell;
+  if(arr)
+    {
+      _discr_per_cell=arr->selectByTupleId2(beginCellIds,endCellIds,stepCellIds);
+    }
+}
+
 void MEDCouplingFieldDiscretizationPerCell::updateTime() const
 {
   if(_discr_per_cell)
@@ -1056,6 +1133,10 @@ MEDCouplingFieldDiscretizationGauss::MEDCouplingFieldDiscretizationGauss(const M
 {
 }
 
+MEDCouplingFieldDiscretizationGauss::MEDCouplingFieldDiscretizationGauss(const MEDCouplingFieldDiscretizationGauss& other, int beginCellIds, int endCellIds, int stepCellIds):MEDCouplingFieldDiscretizationPerCell(other,beginCellIds,endCellIds,stepCellIds),_loc(other._loc)
+{
+}
+
 TypeOfField MEDCouplingFieldDiscretizationGauss::getEnum() const
 {
   return TYPE;
@@ -1123,6 +1204,11 @@ MEDCouplingFieldDiscretization *MEDCouplingFieldDiscretizationGauss::clonePart(c
   return new MEDCouplingFieldDiscretizationGauss(*this,startCellIds,endCellIds);
 }
 
+MEDCouplingFieldDiscretization *MEDCouplingFieldDiscretizationGauss::clonePartRange(int beginCellIds, int endCellIds, int stepCellIds) const
+{
+  return new MEDCouplingFieldDiscretizationGauss(*this,beginCellIds,endCellIds,stepCellIds);
+}
+
 std::string MEDCouplingFieldDiscretizationGauss::getStringRepr() const
 {
   std::ostringstream oss; oss << REPR << "." << std::endl;
@@ -1476,8 +1562,56 @@ MEDCouplingMesh *MEDCouplingFieldDiscretizationGauss::buildSubMeshData(const MED
 {
   if(!mesh)
     throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationGauss::buildSubMeshData : NULL input mesh !");
-  di=computeTupleIdsToSelectFromCellIds(mesh,start,end);
-  return mesh->buildPart(start,end);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> diSafe=computeTupleIdsToSelectFromCellIds(mesh,start,end);
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPart(start,end);
+  di=diSafe.retn();
+  return ret.retn();
+}
+
+/*!
+ * This method is strictly equivalent to MEDCouplingFieldDiscretizationGauss::buildSubMeshData except that it is optimized for input defined as a range of cell ids.
+ * 
+ * \param [out] beginOut Valid only if \a di is NULL
+ * \param [out] endOut Valid only if \a di is NULL
+ * \param [out] stepOut Valid only if \a di is NULL
+ * \param [out] di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array if no output range is foundable.
+ *
+ * \sa MEDCouplingFieldDiscretizationGauss::buildSubMeshData
+ */
+MEDCouplingMesh *MEDCouplingFieldDiscretizationGauss::buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const
+{
+  if(stepCellIds!=1)//even for stepCellIds==-1 the output will not be a range
+    return MEDCouplingFieldDiscretization::buildSubMeshDataRange(mesh,beginCellIds,endCellIds,stepCellIds,beginOut,endOut,stepOut,di);
+  if(!mesh)
+    throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationGauss::buildSubMeshDataRange : NULL input mesh !");
+  if(!_discr_per_cell)
+    throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationGauss::buildSubMeshDataRange : no discretization array set !");
+  di=0; beginOut=0; endOut=0; stepOut=stepCellIds;
+  const char msg[]="MEDCouplingFieldDiscretizationGauss::buildSubMeshDataRange : cell #";
+  int nbOfTuples=_discr_per_cell->getNumberOfTuples();
+  const int *w=_discr_per_cell->begin();
+  int nbMaxOfLocId=(int)_loc.size();
+  for(int i=0;i<nbOfTuples;i++,w++)
+    {
+      if(*w!=DFT_INVALID_LOCID_VALUE)
+        {
+          if(*w>=0 && *w<nbMaxOfLocId)
+            {
+              int delta=_loc[*w].getNumberOfGaussPt();
+              if(i<beginCellIds)
+                beginOut+=delta;
+              endOut+=delta;
+              if(i>=endCellIds)
+                break;
+            }
+          else
+            { std::ostringstream oss; oss << msg << i << " has invalid id (" << *w << ") ! Should be in [0," << nbMaxOfLocId << ") !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
+        }
+      else
+        { std::ostringstream oss; oss << msg << i << " is detected as orphan !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
+    }
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPartRange(beginCellIds,endCellIds,stepCellIds);
+  return ret.retn();
 }
 
 /*!
@@ -1613,7 +1747,7 @@ int MEDCouplingFieldDiscretizationGauss::getGaussLocalizationIdOfOneCell(int cel
 {
   if(!_discr_per_cell)
     throw INTERP_KERNEL::Exception("No Gauss localization still set !");
-  int locId=_discr_per_cell->getConstPointer()[cellId];
+  int locId=_discr_per_cell->begin()[cellId];
   if(locId<0)
     throw INTERP_KERNEL::Exception("No Gauss localization set for the specified cell !");
   return locId;
@@ -1685,7 +1819,7 @@ DataArrayInt *MEDCouplingFieldDiscretizationGauss::buildNbOfGaussPointPerCellFie
     throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationGauss::buildNbOfGaussPointPerCellField : no discretization array set !");
   int nbOfTuples=_discr_per_cell->getNumberOfTuples();
   MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
-  const int *w=_discr_per_cell->getConstPointer();
+  const int *w=_discr_per_cell->begin();
   ret->alloc(nbOfTuples,1);
   int *valsToFill=ret->getPointer();
   int nbMaxOfLocId=(int)_loc.size();
@@ -1720,7 +1854,7 @@ void MEDCouplingFieldDiscretizationGauss::reprQuickOverview(std::ostream& stream
  */
 void MEDCouplingFieldDiscretizationGauss::zipGaussLocalizations()
 {
-  const int *start=_discr_per_cell->getConstPointer();
+  const int *start=_discr_per_cell->begin();
   int nbOfTuples=_discr_per_cell->getNumberOfTuples();
   INTERP_KERNEL::AutoPtr<int> tmp=new int[_loc.size()];
   std::fill((int *)tmp,(int *)tmp+_loc.size(),-2);
@@ -2136,10 +2270,49 @@ MEDCouplingMesh *MEDCouplingFieldDiscretizationGaussNE::buildSubMeshData(const M
 {
   if(!mesh)
     throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationGaussNE::buildSubMeshData : NULL input mesh !");
-  di=computeTupleIdsToSelectFromCellIds(mesh,start,end);
-  return mesh->buildPart(start,end);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> diSafe=computeTupleIdsToSelectFromCellIds(mesh,start,end);
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPart(start,end);
+  di=diSafe.retn();
+  return ret.retn();
+}
+
+/*!
+ * This method is strictly equivalent to MEDCouplingFieldDiscretizationGauss::buildSubMeshData except that it is optimized for input defined as a range of cell ids.
+ * 
+ * \param [out] beginOut Valid only if \a di is NULL
+ * \param [out] endOut Valid only if \a di is NULL
+ * \param [out] stepOut Valid only if \a di is NULL
+ * \param [out] di is an array returned that specifies entity ids (nodes, cells, Gauss points... ) in array if no output range is foundable.
+ *
+ * \sa MEDCouplingFieldDiscretizationGauss::buildSubMeshData
+ */
+MEDCouplingMesh *MEDCouplingFieldDiscretizationGaussNE::buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const
+{
+  if(stepCellIds!=1)//even for stepCellIds==-1 the output will not be a range
+    return MEDCouplingFieldDiscretization::buildSubMeshDataRange(mesh,beginCellIds,endCellIds,stepCellIds,beginOut,endOut,stepOut,di);
+  if(!mesh)
+    throw INTERP_KERNEL::Exception("MEDCouplingFieldDiscretizationGaussNE::buildSubMeshDataRange : NULL input mesh !");
+  int nbOfCells=mesh->getNumberOfCells();
+  di=0; beginOut=0; endOut=0; stepOut=stepCellIds;
+  const char msg[]="MEDCouplingFieldDiscretizationGaussNE::buildSubMeshDataRange : cell #";
+  for(int i=0;i<nbOfCells;i++)
+    {
+      INTERP_KERNEL::NormalizedCellType type=mesh->getTypeOfCell(i);
+      const INTERP_KERNEL::CellModel& cm=INTERP_KERNEL::CellModel::GetCellModel(type);
+      if(cm.isDynamic())
+        { std::ostringstream oss; oss << msg << i << " presence of dynamic cell (polygons and polyedrons) ! Not implemented !"; throw INTERP_KERNEL::Exception(oss.str().c_str()); }
+      int delta=cm.getNumberOfNodes();
+      if(i<beginCellIds)
+        beginOut+=delta;
+      endOut+=delta;
+      if(i>=endCellIds)
+        break;
+    }
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> ret=mesh->buildPartRange(beginCellIds,endCellIds,stepCellIds);
+  return ret.retn();
 }
 
+
 /*!
  * This method returns a tuple ids selection from cell ids selection [start;end).
  * This method is called by MEDCouplingFieldDiscretizationGaussNE::buildSubMeshData to return parameter \b di.
diff --git a/src/MEDCoupling/MEDCouplingFieldDiscretization.hxx b/src/MEDCoupling/MEDCouplingFieldDiscretization.hxx
index 96da042d0..22e40cea7 100644
--- a/src/MEDCoupling/MEDCouplingFieldDiscretization.hxx
+++ b/src/MEDCoupling/MEDCouplingFieldDiscretization.hxx
@@ -55,6 +55,7 @@ namespace ParaMEDMEM
     virtual MEDCouplingFieldDiscretization *deepCpy() const;
     virtual MEDCouplingFieldDiscretization *clone() const = 0;
     virtual MEDCouplingFieldDiscretization *clonePart(const int *startCellIds, const int *endCellIds) const;
+    virtual MEDCouplingFieldDiscretization *clonePartRange(int beginCellIds, int endCellIds, int stepCellIds) const;
     virtual std::string getStringRepr() const = 0;
     virtual const char *getRepr() const = 0;
     virtual int getNumberOfTuples(const MEDCouplingMesh *mesh) const throw(INTERP_KERNEL::Exception) = 0;
@@ -78,6 +79,7 @@ namespace ParaMEDMEM
     virtual DataArrayDouble *getValueOnMulti(const DataArrayDouble *arr, const MEDCouplingMesh *mesh, const double *loc, int nbOfPoints) const = 0;
     virtual DataArrayInt *computeTupleIdsToSelectFromCellIds(const MEDCouplingMesh *mesh, const int *startCellIds, const int *endCellIds) const = 0;
     virtual MEDCouplingMesh *buildSubMeshData(const MEDCouplingMesh *mesh, const int *start, const int *end, DataArrayInt *&di) const = 0;
+    virtual MEDCouplingMesh *buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const;
     virtual void renumberValuesOnNodes(double epsOnVals, const int *old2New, int newNbOfNodes, DataArrayDouble *arr) const = 0;
     virtual void renumberValuesOnCells(double epsOnVals, const MEDCouplingMesh *mesh, const int *old2New, int newSz, DataArrayDouble *arr) const = 0;
     virtual void renumberValuesOnCellsR(const MEDCouplingMesh *mesh, const int *new2old, int newSz, DataArrayDouble *arr) const = 0;
@@ -135,6 +137,7 @@ namespace ParaMEDMEM
     void renumberValuesOnCells(double epsOnVals, const MEDCouplingMesh *mesh, const int *old2New, int newSz, DataArrayDouble *arr) const;
     void renumberValuesOnCellsR(const MEDCouplingMesh *mesh, const int *new2old, int newSz, DataArrayDouble *arr) const;
     MEDCouplingMesh *buildSubMeshData(const MEDCouplingMesh *mesh, const int *start, const int *end, DataArrayInt *&di) const;
+    MEDCouplingMesh *buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const;
     DataArrayInt *computeTupleIdsToSelectFromCellIds(const MEDCouplingMesh *mesh, const int *startCellIds, const int *endCellIds) const;
     void reprQuickOverview(std::ostream& stream) const throw(INTERP_KERNEL::Exception);
   public:
@@ -155,6 +158,7 @@ namespace ParaMEDMEM
                                             DataArrayInt *&cellRestriction, DataArrayInt *&trueTupleRestriction) const throw(INTERP_KERNEL::Exception);
     void checkCoherencyBetween(const MEDCouplingMesh *mesh, const DataArrayDouble *da) const throw(INTERP_KERNEL::Exception);
     MEDCouplingMesh *buildSubMeshData(const MEDCouplingMesh *mesh, const int *start, const int *end, DataArrayInt *&di) const;
+    MEDCouplingMesh *buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const;
     DataArrayInt *computeTupleIdsToSelectFromCellIds(const MEDCouplingMesh *mesh, const int *startCellIds, const int *endCellIds) const;
     void renumberValuesOnNodes(double epsOnVals, const int *old2New, int newNbOfNodes, DataArrayDouble *arr) const;
     void renumberValuesOnCells(double epsOnVals, const MEDCouplingMesh *mesh, const int *old2New, int newSz, DataArrayDouble *arr) const;
@@ -197,6 +201,7 @@ namespace ParaMEDMEM
   protected:
     MEDCouplingFieldDiscretizationPerCell();
     MEDCouplingFieldDiscretizationPerCell(const MEDCouplingFieldDiscretizationPerCell& other, const int *startCellIds, const int *endCellIds);
+    MEDCouplingFieldDiscretizationPerCell(const MEDCouplingFieldDiscretizationPerCell& other, int beginCellIds, int endCellIds, int stepCellIds);
     ~MEDCouplingFieldDiscretizationPerCell();
     void updateTime() const;
     std::size_t getHeapMemorySize() const;
@@ -220,6 +225,7 @@ namespace ParaMEDMEM
     bool isEqualWithoutConsideringStr(const MEDCouplingFieldDiscretization *other, double eps) const;
     MEDCouplingFieldDiscretization *clone() const;
     MEDCouplingFieldDiscretization *clonePart(const int *startCellIds, const int *endCellIds) const;
+    MEDCouplingFieldDiscretization *clonePartRange(int beginCellIds, int endCellIds, int stepCellIds) const;
     std::string getStringRepr() const;
     const char *getRepr() const;
     std::size_t getHeapMemorySize() const;
@@ -244,6 +250,7 @@ namespace ParaMEDMEM
     void getValueOnPos(const DataArrayDouble *arr, const MEDCouplingMesh *mesh, int i, int j, int k, double *res) const;
     DataArrayDouble *getValueOnMulti(const DataArrayDouble *arr, const MEDCouplingMesh *mesh, const double *loc, int nbOfPoints) const;
     MEDCouplingMesh *buildSubMeshData(const MEDCouplingMesh *mesh, const int *start, const int *end, DataArrayInt *&di) const;
+    MEDCouplingMesh *buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const;
     DataArrayInt *computeTupleIdsToSelectFromCellIds(const MEDCouplingMesh *mesh, const int *startCellIds, const int *endCellIds) const;
     void renumberValuesOnNodes(double epsOnVals, const int *old2New, int newNbOfNodes, DataArrayDouble *arr) const;
     void renumberValuesOnCells(double epsOnVals, const MEDCouplingMesh *mesh, const int *old2New, int newSz, DataArrayDouble *arr) const;
@@ -266,6 +273,7 @@ namespace ParaMEDMEM
     void reprQuickOverview(std::ostream& stream) const throw(INTERP_KERNEL::Exception);
   protected:
     MEDCouplingFieldDiscretizationGauss(const MEDCouplingFieldDiscretizationGauss& other, const int *startCellIds=0, const int *endCellIds=0);
+    MEDCouplingFieldDiscretizationGauss(const MEDCouplingFieldDiscretizationGauss& other, int beginCellIds, int endCellIds, int stepCellIds);
     void zipGaussLocalizations();
     int getOffsetOfCell(int cellId) const throw(INTERP_KERNEL::Exception);
     void checkLocalizationId(int locId) const throw(INTERP_KERNEL::Exception);
@@ -305,6 +313,7 @@ namespace ParaMEDMEM
     void getValueOnPos(const DataArrayDouble *arr, const MEDCouplingMesh *mesh, int i, int j, int k, double *res) const;
     DataArrayDouble *getValueOnMulti(const DataArrayDouble *arr, const MEDCouplingMesh *mesh, const double *loc, int nbOfPoints) const;
     MEDCouplingMesh *buildSubMeshData(const MEDCouplingMesh *mesh, const int *start, const int *end, DataArrayInt *&di) const;
+    MEDCouplingMesh *buildSubMeshDataRange(const MEDCouplingMesh *mesh, int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt *&di) const;
     DataArrayInt *computeTupleIdsToSelectFromCellIds(const MEDCouplingMesh *mesh, const int *startCellIds, const int *endCellIds) const;
     void renumberValuesOnNodes(double epsOnVals, const int *old2New, int newNbOfNodes, DataArrayDouble *arr) const;
     void renumberValuesOnCells(double epsOnVals, const MEDCouplingMesh *mesh, const int *old2New, int newSz, DataArrayDouble *arr) const;
diff --git a/src/MEDCoupling/MEDCouplingFieldDouble.cxx b/src/MEDCoupling/MEDCouplingFieldDouble.cxx
index 52e53a9c3..81e9dc6f3 100644
--- a/src/MEDCoupling/MEDCouplingFieldDouble.cxx
+++ b/src/MEDCoupling/MEDCouplingFieldDouble.cxx
@@ -496,15 +496,15 @@ DataArrayInt *MEDCouplingFieldDouble::getIdsInRange(double vmin, double vmax) co
  *
  * If \a this is field on node lying on a mesh that have 10 cells and 11 nodes for example. If part contains following cellIds [3,7,6].
  * \a this is currently contains 11 tuples. If the restriction of mesh to 3 cells leads to a mesh with 6 nodes, the returned field,
- * will contain 6 tuples and this field will lie on this restricted mesh. 
+ * will contain 6 tuples and this field will lie on this restricted mesh.
+ *
+ * \sa MEDCouplingFieldDouble::buildSubPartRange
  */
 MEDCouplingFieldDouble *MEDCouplingFieldDouble::buildSubPart(const DataArrayInt *part) const throw(INTERP_KERNEL::Exception)
 {
   if(part==0)
     throw INTERP_KERNEL::Exception("MEDCouplingFieldDouble::buildSubPart : not empty array must be passed to this method !");
-  const int *start=part->getConstPointer();
-  const int *end=start+part->getNbOfElems();
-  return buildSubPart(start,end);
+  return buildSubPart(part->begin(),part->end());
 }
 
 /*!
@@ -535,7 +535,7 @@ MEDCouplingFieldDouble *MEDCouplingFieldDouble::buildSubPart(const DataArrayInt
  * \ref cpp_mcfielddouble_subpart1 "Here a C++ example."
  *
  * \ref py_mcfielddouble_subpart1 "Here a Python example."
- * \sa ParaMEDMEM::MEDCouplingFieldDouble::buildSubPart(const DataArrayInt *) const
+ * \sa ParaMEDMEM::MEDCouplingFieldDouble::buildSubPart(const DataArrayInt *) const, MEDCouplingFieldDouble::buildSubPartRange
  */
 MEDCouplingFieldDouble *MEDCouplingFieldDouble::buildSubPart(const int *partBg, const int *partEnd) const throw(INTERP_KERNEL::Exception)
 {
@@ -566,6 +566,49 @@ MEDCouplingFieldDouble *MEDCouplingFieldDouble::buildSubPart(const int *partBg,
   return ret.retn();
 }
 
+/*!
+ * This method is equivalent to MEDCouplingFieldDouble::buildSubPart, the only difference is that the input range of cell ids is
+ * given using a range given \a begin, \a end and \a step to optimize the part computation.
+ * 
+ * \sa MEDCouplingFieldDouble::buildSubPart
+ */
+MEDCouplingFieldDouble *MEDCouplingFieldDouble::buildSubPartRange(int begin, int end, int step) const throw(INTERP_KERNEL::Exception)
+{
+  if(!((const MEDCouplingFieldDiscretization *)_type))
+    throw INTERP_KERNEL::Exception("MEDCouplingFieldDouble::buildSubPart : Expecting a not NULL spatial discretization !");
+  DataArrayInt *arrSelect;
+  int beginOut,endOut,stepOut;
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingMesh> m=_type->buildSubMeshDataRange(_mesh,begin,end,step,beginOut,endOut,stepOut,arrSelect);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> arrSelect2(arrSelect);
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret=clone(false);//quick shallow copy.
+  const MEDCouplingFieldDiscretization *disc=getDiscretization();
+  if(disc)
+    ret->setDiscretization(MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDiscretization>(disc->clonePartRange(begin,end,step)));
+  ret->setMesh(m);
+  std::vector<DataArrayDouble *> arrays;
+  _time_discr->getArrays(arrays);
+  std::vector<DataArrayDouble *> arrs;
+  std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> > arrsSafe;
+  for(std::vector<DataArrayDouble *>::const_iterator iter=arrays.begin();iter!=arrays.end();iter++)
+    {
+      DataArrayDouble *arr=0;
+      if(*iter)
+        {
+          if(arrSelect)
+            {
+              const int *arrSelBg=arrSelect->begin();
+              const int *arrSelEnd=arrSelect->end();
+              arr=(*iter)->selectByTupleIdSafe(arrSelBg,arrSelEnd);
+            }
+          else
+            arr=(*iter)->selectByTupleId2(beginOut,endOut,stepOut);
+        }
+      arrs.push_back(arr); arrsSafe.push_back(arr);
+    }
+  ret->_time_discr->setArrays(arrs,0);
+  return ret.retn();
+}
+
 TypeOfTimeDiscretization MEDCouplingFieldDouble::getTimeDiscretization() const
 {
   return _time_discr->getEnum();
diff --git a/src/MEDCoupling/MEDCouplingFieldDouble.hxx b/src/MEDCoupling/MEDCouplingFieldDouble.hxx
index 5eb82cf67..6e3c3282f 100644
--- a/src/MEDCoupling/MEDCouplingFieldDouble.hxx
+++ b/src/MEDCoupling/MEDCouplingFieldDouble.hxx
@@ -58,6 +58,7 @@ namespace ParaMEDMEM
     DataArrayInt *getIdsInRange(double vmin, double vmax) const throw(INTERP_KERNEL::Exception);
     MEDCouplingFieldDouble *buildSubPart(const DataArrayInt *part) const throw(INTERP_KERNEL::Exception);
     MEDCouplingFieldDouble *buildSubPart(const int *partBg, const int *partEnd) const throw(INTERP_KERNEL::Exception);
+    MEDCouplingFieldDouble *buildSubPartRange(int begin, int end, int step) const throw(INTERP_KERNEL::Exception);
     MEDCouplingFieldDouble *deepCpy() const;
     MEDCouplingFieldDouble *clone(bool recDeepCpy) const;
     MEDCouplingFieldDouble *cloneWithMesh(bool recDeepCpy) const;
diff --git a/src/MEDCoupling/MEDCouplingMemArray.cxx b/src/MEDCoupling/MEDCouplingMemArray.cxx
index 07d0c484f..9ad55aaef 100644
--- a/src/MEDCoupling/MEDCouplingMemArray.cxx
+++ b/src/MEDCoupling/MEDCouplingMemArray.cxx
@@ -1435,7 +1435,7 @@ DataArrayDouble *DataArrayDouble::selectByTupleIdSafe(const int *new2OldBg, cons
     if(*w>=0 && *w<oldNbOfTuples)
       std::copy(srcPt+(*w)*nbComp,srcPt+((*w)+1)*nbComp,pt+i*nbComp);
     else
-      throw INTERP_KERNEL::Exception("DataArrayInt::selectByTupleIdSafe : some ids has been detected to be out of [0,this->getNumberOfTuples) !");
+      throw INTERP_KERNEL::Exception("DataArrayDouble::selectByTupleIdSafe : some ids has been detected to be out of [0,this->getNumberOfTuples) !");
   ret->copyStringInfoFrom(*this);
   return ret.retn();
 }
@@ -1453,7 +1453,6 @@ DataArrayDouble *DataArrayDouble::selectByTupleIdSafe(const int *new2OldBg, cons
  *  \param [in] step - index increment to get index of the next tuple to copy.
  *  \return DataArrayDouble * - the new instance of DataArrayDouble that the caller
  *          is to delete using decrRef() as it is no more needed.
- *  \throw If (\a end2 < \a bg) or (\a step <= 0).
  *  \sa DataArrayDouble::substr.
  */
 DataArrayDouble *DataArrayDouble::selectByTupleId2(int bg, int end2, int step) const throw(INTERP_KERNEL::Exception)
@@ -1461,7 +1460,7 @@ DataArrayDouble *DataArrayDouble::selectByTupleId2(int bg, int end2, int step) c
   checkAllocated();
   MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> ret=DataArrayDouble::New();
   int nbComp=getNumberOfComponents();
-  int newNbOfTuples=GetNumberOfItemGivenBES(bg,end2,step,"DataArrayDouble::selectByTupleId2 : ");
+  int newNbOfTuples=GetNumberOfItemGivenBESRelative(bg,end2,step,"DataArrayDouble::selectByTupleId2 : ");
   ret->alloc(newNbOfTuples,nbComp);
   double *pt=ret->getPointer();
   const double *srcPt=getConstPointer()+bg*nbComp;
@@ -6416,7 +6415,6 @@ DataArrayInt *DataArrayInt::selectByTupleIdSafe(const int *new2OldBg, const int
  *  \param [in] step - index increment to get index of the next tuple to copy.
  *  \return DataArrayInt * - the new instance of DataArrayInt that the caller
  *          is to delete using decrRef() as it is no more needed.
- *  \throw If (\a end2 < \a bg) or (\a step <= 0).
  *  \sa DataArrayInt::substr.
  */
 DataArrayInt *DataArrayInt::selectByTupleId2(int bg, int end2, int step) const throw(INTERP_KERNEL::Exception)
@@ -6424,7 +6422,7 @@ DataArrayInt *DataArrayInt::selectByTupleId2(int bg, int end2, int step) const t
   checkAllocated();
   MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=DataArrayInt::New();
   int nbComp=getNumberOfComponents();
-  int newNbOfTuples=GetNumberOfItemGivenBES(bg,end2,step,"DataArrayInt::selectByTupleId2 : ");
+  int newNbOfTuples=GetNumberOfItemGivenBESRelative(bg,end2,step,"DataArrayInt::selectByTupleId2 : ");
   ret->alloc(newNbOfTuples,nbComp);
   int *pt=ret->getPointer();
   const int *srcPt=getConstPointer()+bg*nbComp;
diff --git a/src/MEDCoupling/MEDCouplingMemArrayChar.cxx b/src/MEDCoupling/MEDCouplingMemArrayChar.cxx
index f38bd25c9..0906a91ad 100644
--- a/src/MEDCoupling/MEDCouplingMemArrayChar.cxx
+++ b/src/MEDCoupling/MEDCouplingMemArrayChar.cxx
@@ -580,7 +580,7 @@ DataArrayChar *DataArrayChar::selectByTupleId2(int bg, int end2, int step) const
   checkAllocated();
   MEDCouplingAutoRefCountObjectPtr<DataArrayChar> ret=buildEmptySpecializedDAChar();
   int nbComp=getNumberOfComponents();
-  int newNbOfTuples=GetNumberOfItemGivenBES(bg,end2,step,"DataArrayInt::selectByTupleId2 : ");
+  int newNbOfTuples=GetNumberOfItemGivenBESRelative(bg,end2,step,"DataArrayInt::selectByTupleId2 : ");
   ret->alloc(newNbOfTuples,nbComp);
   char *pt=ret->getPointer();
   const char *srcPt=getConstPointer()+bg*nbComp;
diff --git a/src/MEDCoupling/MEDCouplingMesh.cxx b/src/MEDCoupling/MEDCouplingMesh.cxx
index 726785406..1e1f6d278 100644
--- a/src/MEDCoupling/MEDCouplingMesh.cxx
+++ b/src/MEDCoupling/MEDCouplingMesh.cxx
@@ -231,6 +231,28 @@ bool MEDCouplingMesh::areCompatibleForMerge(const MEDCouplingMesh *other) const
   return true;
 }
 
+/*!
+ * This method is equivalent to MEDCouplingMesh::buildPart method except that here the cell ids are specified using slice \a beginCellIds \a endCellIds and \a stepCellIds.
+ *
+ * \sa MEDCouplingMesh::buildPart
+ */
+MEDCouplingMesh *MEDCouplingMesh::buildPartRange(int beginCellIds, int endCellIds, int stepCellIds) const throw(INTERP_KERNEL::Exception)
+{
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIds=DataArrayInt::Range(beginCellIds,endCellIds,stepCellIds);
+  return buildPart(cellIds->begin(),cellIds->end());
+}
+
+/*!
+ * This method is equivalent to MEDCouplingMesh::buildPartAndReduceNodes method except that here the cell ids are specified using slice \a beginCellIds \a endCellIds and \a stepCellIds.
+ *
+ * \sa MEDCouplingMesh::buildPartAndReduceNodes
+ */
+MEDCouplingMesh *MEDCouplingMesh::buildPartRangeAndReduceNodes(int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt*& arr) const throw(INTERP_KERNEL::Exception)
+{
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> cellIds=DataArrayInt::Range(beginCellIds,endCellIds,stepCellIds);
+  return buildPartAndReduceNodes(cellIds->begin(),cellIds->end(),arr);
+}
+
 /*!
  * This method builds a field lying on 'this' with 'nbOfComp' components.
  * 'func' is a pointer that points to a function that takes 2 arrays in parameter and returns a boolean.
diff --git a/src/MEDCoupling/MEDCouplingMesh.hxx b/src/MEDCoupling/MEDCouplingMesh.hxx
index 83210b6e9..ff714a769 100644
--- a/src/MEDCoupling/MEDCouplingMesh.hxx
+++ b/src/MEDCoupling/MEDCouplingMesh.hxx
@@ -117,6 +117,8 @@ namespace ParaMEDMEM
     virtual MEDCouplingMesh *mergeMyselfWith(const MEDCouplingMesh *other) const = 0;
     virtual MEDCouplingMesh *buildPart(const int *start, const int *end) const = 0;
     virtual MEDCouplingMesh *buildPartAndReduceNodes(const int *start, const int *end, DataArrayInt*& arr) const = 0;
+    virtual MEDCouplingMesh *buildPartRange(int beginCellIds, int endCellIds, int stepCellIds) const throw(INTERP_KERNEL::Exception);
+    virtual MEDCouplingMesh *buildPartRangeAndReduceNodes(int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt*& arr) const throw(INTERP_KERNEL::Exception);
     virtual MEDCouplingUMesh *buildUnstructured() const throw(INTERP_KERNEL::Exception) = 0;
     virtual DataArrayInt *simplexize(int policy) throw(INTERP_KERNEL::Exception) = 0;
     virtual bool areCompatibleForMerge(const MEDCouplingMesh *other) const;
diff --git a/src/MEDCoupling/MEDCouplingPointSet.cxx b/src/MEDCoupling/MEDCouplingPointSet.cxx
index 32c1efa3c..38e9f1f0b 100644
--- a/src/MEDCoupling/MEDCouplingPointSet.cxx
+++ b/src/MEDCoupling/MEDCouplingPointSet.cxx
@@ -259,11 +259,11 @@ DataArrayInt *MEDCouplingPointSet::buildPermArrayForMergeNode(double precision,
   DataArrayInt *comm,*commI;
   findCommonNodes(precision,limitNodeId,comm,commI);
   int oldNbOfNodes=getNumberOfNodes();
-  DataArrayInt *ret=buildNewNumberingFromCommonNodesFormat(comm,commI,newNbOfNodes);
+  MEDCouplingAutoRefCountObjectPtr<DataArrayInt> ret=buildNewNumberingFromCommonNodesFormat(comm,commI,newNbOfNodes);
   areNodesMerged=(oldNbOfNodes!=newNbOfNodes);
   comm->decrRef();
   commI->decrRef();
-  return ret;
+  return ret.retn();
 }
 
 /*!
@@ -1044,11 +1044,32 @@ MEDCouplingMesh *MEDCouplingPointSet::buildPart(const int *start, const int *end
  */
 MEDCouplingMesh *MEDCouplingPointSet::buildPartAndReduceNodes(const int *start, const int *end, DataArrayInt*& arr) const
 {
-  MEDCouplingPointSet *ret=buildPartOfMySelf(start,end,true);
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingPointSet> ret=buildPartOfMySelf(start,end,true);
   arr=ret->zipCoordsTraducer();
-  return ret;
+  return ret.retn();
+}
+
+/*!
+ * This method specialized the MEDCouplingMesh::buildPartRange
+ *
+ * \sa MEDCouplingUMesh::buildPartOfMySelf2
+ */
+MEDCouplingMesh *MEDCouplingPointSet::buildPartRange(int beginCellIds, int endCellIds, int stepCellIds) const throw(INTERP_KERNEL::Exception)
+{
+  return buildPartOfMySelf2(beginCellIds,endCellIds,stepCellIds,true);
 }
 
+/*!
+ * This method specialized the MEDCouplingMesh::buildPartRangeAndReduceNodes
+ *
+ * \sa MEDCouplingUMesh::buildPartOfMySelf2
+ */
+MEDCouplingMesh *MEDCouplingPointSet::buildPartRangeAndReduceNodes(int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt*& arr) const throw(INTERP_KERNEL::Exception)
+{
+  MEDCouplingAutoRefCountObjectPtr<MEDCouplingPointSet> ret=buildPartOfMySelf2(beginCellIds,endCellIds,stepCellIds,true);
+  arr=ret->zipCoordsTraducer();
+  return ret.retn();
+}
 
 /*!
  * 'This' is expected to be of spaceDim==2. Idem for 'center' and 'vect'
diff --git a/src/MEDCoupling/MEDCouplingPointSet.hxx b/src/MEDCoupling/MEDCouplingPointSet.hxx
index 908ef71e5..e0ef76118 100644
--- a/src/MEDCoupling/MEDCouplingPointSet.hxx
+++ b/src/MEDCoupling/MEDCouplingPointSet.hxx
@@ -94,6 +94,8 @@ namespace ParaMEDMEM
     static void Rotate3DAlg(const double *center, const double *vect, double angle, int nbNodes, double *coords);
     MEDCouplingMesh *buildPart(const int *start, const int *end) const;
     MEDCouplingMesh *buildPartAndReduceNodes(const int *start, const int *end, DataArrayInt*& arr) const;
+    MEDCouplingMesh *buildPartRange(int beginCellIds, int endCellIds, int stepCellIds) const throw(INTERP_KERNEL::Exception);
+    MEDCouplingMesh *buildPartRangeAndReduceNodes(int beginCellIds, int endCellIds, int stepCellIds, int& beginOut, int& endOut, int& stepOut, DataArrayInt*& arr) const throw(INTERP_KERNEL::Exception);
     virtual MEDCouplingPointSet *buildPartOfMySelf(const int *start, const int *end, bool keepCoords=true) const = 0;
     virtual MEDCouplingPointSet *buildPartOfMySelf2(int start, int end, int step, bool keepCoords=true) const throw(INTERP_KERNEL::Exception) = 0;
     virtual MEDCouplingPointSet *buildPartOfMySelfNode(const int *start, const int *end, bool fullyIn) const = 0;