Actual source code: sp1wd.c


  2: #include <petscmat.h>
  3: #include <petsc/private/matorderimpl.h>

  5: /*
  6:     MatGetOrdering_1WD - Find the 1-way dissection ordering of a given matrix.
  7: */
  8: PETSC_INTERN PetscErrorCode MatGetOrdering_1WD(Mat mat,MatOrderingType type,IS *row,IS *col)
  9: {
 10:   PetscInt       i,*mask,*xls,nblks,*xblk,*ls,nrow,*perm;
 11:   const PetscInt *ia,*ja;
 12:   PetscBool      done;

 14:   MatGetRowIJ(mat,1,PETSC_TRUE,PETSC_TRUE,&nrow,&ia,&ja,&done);

 17:   PetscMalloc5(nrow,&mask,nrow+1,&xls,nrow,&ls,nrow+1,&xblk,nrow,&perm);
 18:   SPARSEPACKgen1wd(&nrow,ia,ja,mask,&nblks,xblk,perm,xls,ls);
 19:   MatRestoreRowIJ(mat,1,PETSC_TRUE,PETSC_TRUE,NULL,&ia,&ja,&done);

 21:   for (i=0; i<nrow; i++) perm[i]--;

 23:   ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,PETSC_COPY_VALUES,row);
 24:   ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,PETSC_COPY_VALUES,col);
 25:   PetscFree5(mask,xls,ls,xblk,perm);
 26:   return 0;
 27: }