Actual source code: spqmd.c

  1: #define PETSCMAT_DLL

 3:  #include petscmat.h
 4:  #include ../src/mat/order/order.h

  7: /*
  8:     MatOrdering_QMD - Find the Quotient Minimum Degree ordering of a given matrix.
  9: */
 12: PetscErrorCode  MatOrdering_QMD(Mat mat,const MatOrderingType type,IS *row,IS *col)
 13: {
 14:   PetscInt       i,  *deg,*marker,*rchset,*nbrhd,*qsize,*qlink,nofsub,*iperm,nrow;
 16:   PetscInt       *ia,*ja,*perm;
 17:   PetscTruth      done;

 20:   MatGetRowIJ(mat,1,PETSC_TRUE,PETSC_TRUE,&nrow,&ia,&ja,&done);
 21:   if (!done) SETERRQ(PETSC_ERR_SUP,"Cannot get rows for matrix");

 23:   PetscMalloc(nrow * sizeof(PetscInt),&perm);
 24:   PetscMalloc5(nrow,PetscInt,&iperm,nrow,PetscInt,&deg,nrow,PetscInt,&marker,nrow,PetscInt,&rchset,nrow,PetscInt,&nbrhd);
 25:   PetscMalloc2(nrow,PetscInt,&qsize,nrow,PetscInt,&qlink);
 26:   /* WARNING - genqmd trashes ja */
 27:   SPARSEPACKgenqmd(&nrow,ia,ja,perm,iperm,deg,marker,rchset,nbrhd,qsize,qlink,&nofsub);
 28:   MatRestoreRowIJ(mat,1,PETSC_TRUE,PETSC_TRUE,&nrow,&ia,&ja,&done);

 30:   PetscFree2(qsize,qlink);
 31:   PetscFree5(iperm,deg,marker,rchset,nbrhd);
 32:   for (i=0; i<nrow; i++) perm[i]--;
 33:   ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,row);
 34:   ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,col);
 35:   PetscFree(perm);
 36:   return(0);
 37: }