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 */ 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