return ret.retn();
}
+/*!
+ * This method converts a field on nodes (\a this) to a cell field (returned field). The convertion is a \b non \b conservative remapping !
+ * This method is useful only for users that need a fast convertion from node to cell spatial discretization. The algorithm applied is simply to attach
+ * to each cell the average of values on nodes constituting this cell.
+ *
+ * \return MEDCouplingFieldDouble* - a new instance of MEDCouplingFieldDouble. The
+ * caller is to delete this field using decrRef() as it is no more needed. The returned field will share the same mesh object object than those in \a this.
+ * \throw If \a this spatial discretization is empty or not ON_NODES.
+ * \throw If \a this is not coherent (see MEDCouplingFieldDouble::checkCoherency).
+ *
+ * \warning This method is a \b non \b conservative method of remapping from node spatial discretization to cell spatial discretization.
+ * If a conservative method of interpolation is required ParaMEDMEM::MEDCouplingRemapper class should be used instead with "P1P0" method.
+ */
+MEDCouplingFieldDouble *MEDCouplingFieldDouble::nodeToCellDiscretization() const
+{
+ checkCoherency();
+ TypeOfField tf(getTypeOfField());
+ if(tf!=ON_NODES)
+ throw INTERP_KERNEL::Exception("MEDCouplingFieldDouble::nodeToCellDiscretization : this field is expected to be on ON_NODES !");
+ MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDouble> ret(clone(false));
+ MEDCouplingAutoRefCountObjectPtr<MEDCouplingFieldDiscretizationP0> nsp(new MEDCouplingFieldDiscretizationP0);
+ ret->setDiscretization(nsp);
+ const MEDCouplingMesh *m(getMesh());//m is non empty thanks to checkCoherency call
+ int nbCells(m->getNumberOfCells());
+ std::vector<DataArrayDouble *> arrs(getArrays());
+ std::size_t sz(arrs.size());
+ std::vector< MEDCouplingAutoRefCountObjectPtr<DataArrayDouble> > outArrsSafe(sz); std::vector<DataArrayDouble *> outArrs(sz);
+ for(std::size_t j=0;j<sz;j++)
+ {
+ int nbCompo(arrs[j]->getNumberOfComponents());
+ outArrsSafe[j]=DataArrayDouble::New(); outArrsSafe[j]->alloc(nbCells,nbCompo);
+ outArrsSafe[j]->copyStringInfoFrom(*arrs[j]);
+ outArrs[j]=outArrsSafe[j];
+ double *pt(outArrsSafe[j]->getPointer());
+ const double *srcPt(arrs[j]->begin());
+ for(int i=0;i<nbCells;i++,pt+=nbCompo)
+ {
+ std::vector<int> nodeIds;
+ m->getNodeIdsOfCell(i,nodeIds);
+ std::fill(pt,pt+nbCompo,0.);
+ std::size_t nbNodesInCell(nodeIds.size());
+ for(std::size_t k=0;k<nbNodesInCell;k++)
+ std::transform(srcPt+nodeIds[k]*nbCompo,srcPt+(nodeIds[k]+1)*nbCompo,pt,pt,std::plus<double>());
+ if(nbNodesInCell!=0)
+ std::transform(pt,pt+nbCompo,pt,std::bind2nd(std::multiplies<double>(),1./((double)nbNodesInCell)));
+ else
+ {
+ std::ostringstream oss; oss << "MEDCouplingFieldDouble::nodeToCellDiscretization : Cell id #" << i << " has been detected to have no nodes !";
+ throw INTERP_KERNEL::Exception(oss.str().c_str());
+ }
+ }
+ }
+ ret->setArrays(outArrs);
+ return ret.retn();
+}
+
/*!
* Copies tiny info (component names, name and description) from an \a other field to
* \a this one.
