1 #include <petscmat.h>
2 #include <petsc/private/matorderimpl.h>
3
4 /*
5 MatGetOrdering_1WD - Find the 1-way dissection ordering of a given matrix.
6 */
MatGetOrdering_1WD(Mat mat,MatOrderingType type,IS * row,IS * col)7 PETSC_INTERN PetscErrorCode MatGetOrdering_1WD(Mat mat, MatOrderingType type, IS *row, IS *col)
8 {
9 PetscInt i, *mask, *xls, nblks, *xblk, *ls, nrow, *perm;
10 const PetscInt *ia, *ja;
11 PetscBool done;
12
13 PetscFunctionBegin;
14 PetscCall(MatGetRowIJ(mat, 1, PETSC_TRUE, PETSC_TRUE, &nrow, &ia, &ja, &done));
15 PetscCheck(done, PetscObjectComm((PetscObject)mat), PETSC_ERR_SUP, "Cannot get rows for matrix");
16
17 PetscCall(PetscMalloc5(nrow, &mask, nrow + 1, &xls, nrow, &ls, nrow + 1, &xblk, nrow, &perm));
18 PetscCall(SPARSEPACKgen1wd(&nrow, ia, ja, mask, &nblks, xblk, perm, xls, ls));
19 PetscCall(MatRestoreRowIJ(mat, 1, PETSC_TRUE, PETSC_TRUE, NULL, &ia, &ja, &done));
20
21 for (i = 0; i < nrow; i++) perm[i]--;
22
23 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, nrow, perm, PETSC_COPY_VALUES, row));
24 PetscCall(ISCreateGeneral(PETSC_COMM_SELF, nrow, perm, PETSC_COPY_VALUES, col));
25 PetscCall(PetscFree5(mask, xls, ls, xblk, perm));
26 PetscFunctionReturn(PETSC_SUCCESS);
27 }
28