MeshPartitionx.h

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#ifndef _MESHPARTITIONX_H
#define _MESHPARTITIONX_H
 
#include "../../shared/shared.h"
 
/* local prototypes: */
template <class doubletype> 
int MeshPartitionx(int** pepart,int** pnpart,int numberofelements,int numberofnodes,int* elements,
      int numberofelements2d,int numberofnodes2d,doubletype* elements2d,int* vweights,int numlayers,int elements_width, int meshelementtype,int num_procs){
 
   int noerr=1;
   int i,j;
 
   /*Metis partitioning: */
   int* epart=NULL;
   int* npart=NULL;
   int* index=NULL;
 
   int* epart2d=NULL;
   int* npart2d=NULL;
   int* index2d=NULL;
   int  count=0;
 
 
   switch(meshelementtype){
      case TriaEnum:
      case TetraEnum:
         epart=xNew<int>(numberofelements);
         npart=xNew<int>(numberofnodes);
         index=xNew<int>(elements_width*numberofelements);
         for (i=0;i<numberofelements;i++){
            for (j=0;j<elements_width;j++){
               *(index+elements_width*i+j)=(*(elements+elements_width*i+j))-1; //-1 for C indexing in Metis
            }
         }
 
         /*Partition using Metis:*/
         if (num_procs>1){
#ifdef _HAVE_METIS_
            METIS_PartMeshNodalPatch(numberofelements,numberofnodes,index,vweights,num_procs,epart, npart);
#else
            _error_("metis has not beed installed. Cannot run with more than 1 cpu");
#endif
         }
         else if (num_procs==1){
            /*METIS does not know how to deal with one cpu only!*/
            for (i=0;i<numberofelements;i++) epart[i]=0;
            for (i=0;i<numberofnodes;i++)    npart[i]=0;
         }
         else _error_("At least one processor is required");
         break;
      case PentaEnum:
         /*We have a 3d mesh, made of a regularly extruded 2d mesh. We first partition the 2d mesh, then we extrude the partition: */
 
         /*First build concatenated 2d mesh  from 2d_coll and 2d_noncoll: */
         epart2d=xNew<int>(numberofelements2d);
         npart2d=xNew<int>(numberofnodes2d); 
         index2d=xNew<int>(3*numberofelements2d);
 
         for (i=0;i<numberofelements2d;i++){
            for (j=0;j<3;j++){
               *(index2d+3*i+j)=reCast<int>(*(elements2d+3*i+j))-1; //-1 for C indexing in Metis
            }
         }
 
         /*Partition using Metis:*/
         if (num_procs>1){
#ifdef _HAVE_METIS_
            METIS_PartMeshNodalPatch(numberofelements2d,numberofnodes2d,index2d,vweights,num_procs,epart2d,npart2d);
#else
            _error_("metis has not beed installed. Cannot run with more than 1 cpu");
#endif
         }
         else if (num_procs==1){
            /*METIS does not know how to deal with one cpu only!*/
            for (i=0;i<numberofelements2d;i++) epart2d[i]=0;
            for (i=0;i<numberofnodes2d;i++)    npart2d[i]=0;
         }
         else _error_("At least one processor is required");
 
         /*Extrude epart2d to epart, using numlayers: */
         epart=xNew<int>(numberofelements);
 
         count=0;
         for(i=0;i<(numlayers-1);i++){
            for(j=0;j<numberofelements2d;j++){
               epart[count]=epart2d[j];
               count++;
            }
         }
 
         /*Extrude npart2d to npart, using numlayers: */
         npart=xNew<int>(numberofnodes);
 
         count=0;
         for(i=0;i<(numlayers);i++){
            for(j=0;j<numberofnodes2d;j++){
               npart[count]=npart2d[j];
               count++;
            }
         }
         break;
      default:
         _error_("mesh type "<<EnumToStringx(meshelementtype)<<" not supported yet");
   }
 
   /*Assign output pointer:*/
   *pepart=epart;
   *pnpart=npart;
 
   /*Free ressources: */
   xDelete<int>(index);
   xDelete<int>(epart2d);
   xDelete<int>(npart2d);
   xDelete<int>(index2d);
   return noerr;
}
#endif /* _MESHPARTITIONX_H */