Actual source code: spqmd.c
1: /*$Id: spqmd.c,v 1.40 2001/03/23 23:22:51 balay Exp $*/
3: #include petscmat.h
4: #include src/mat/order/order.h
6: EXTERN_C_BEGIN
7: /*
8: MatOrdering_QMD - Find the Quotient Minimum Degree ordering of a given matrix.
9: */
10: int MatOrdering_QMD(Mat mat,MatOrderingType type,IS *row,IS *col)
11: {
12: int i, *deg,*marker,*rchset,*nbrhd,*qsize,*qlink,nofsub,*iperm,nrow;
13: int ierr,*ia,*ja,*perm;
14: PetscTruth done;
17: MatGetRowIJ(mat,1,PETSC_TRUE,&nrow,&ia,&ja,&done);
18: if (!done) SETERRQ(PETSC_ERR_SUP,"Cannot get rows for matrix");
20: PetscMalloc(nrow * sizeof(int),&perm);
21: PetscMalloc(nrow * sizeof(int),&iperm);
22: PetscMalloc(nrow * sizeof(int),°);
23: PetscMalloc(nrow * sizeof(int),&marker);
24: PetscMalloc(nrow * sizeof(int),&rchset);
25: PetscMalloc(nrow * sizeof(int),&nbrhd);
26: PetscMalloc(nrow * sizeof(int),&qsize);
27: PetscMalloc(nrow * sizeof(int),&qlink);
28: /* WARNING - genqmd trashes ja */
29: SPARSEPACKgenqmd(&nrow,ia,ja,perm,iperm,deg,marker,rchset,nbrhd,qsize,qlink,&nofsub);
30: MatRestoreRowIJ(mat,1,PETSC_TRUE,&nrow,&ia,&ja,&done);
32: PetscFree(deg);
33: PetscFree(marker);
34: PetscFree(rchset);
35: PetscFree(nbrhd);
36: PetscFree(qsize);
37: PetscFree(qlink);
38: PetscFree(iperm);
39: for (i=0; i<nrow; i++) perm[i]--;
40: ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,row);
41: ISCreateGeneral(PETSC_COMM_SELF,nrow,perm,col);
42: PetscFree(perm);
43: return(0);
44: }
45: EXTERN_C_END