Actual source code: ex22.c
2: static char help[] = "Tests matrix ordering routines.\n\n";
4: #include <petscmat.h>
5: extern PetscErrorCode MatGetOrdering_myordering(Mat, MatOrderingType, IS *, IS *);
7: int main(int argc, char **args)
8: {
9: Mat C, Cperm;
10: PetscInt i, j, m = 5, n = 5, Ii, J, ncols;
11: PetscScalar v;
12: PetscMPIInt size;
13: IS rperm, cperm, icperm;
14: const PetscInt *rperm_ptr, *cperm_ptr, *cols;
15: const PetscScalar *vals;
16: PetscBool TestMyorder = PETSC_FALSE;
19: PetscInitialize(&argc, &args, (char *)0, help);
20: MPI_Comm_size(PETSC_COMM_WORLD, &size);
23: /* create the matrix for the five point stencil, YET AGAIN */
24: MatCreateSeqAIJ(PETSC_COMM_SELF, m * n, m * n, 5, NULL, &C);
25: MatSetUp(C);
26: for (i = 0; i < m; i++) {
27: for (j = 0; j < n; j++) {
28: v = -1.0;
29: Ii = j + n * i;
30: if (i > 0) {
31: J = Ii - n;
32: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
33: }
34: if (i < m - 1) {
35: J = Ii + n;
36: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
37: }
38: if (j > 0) {
39: J = Ii - 1;
40: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
41: }
42: if (j < n - 1) {
43: J = Ii + 1;
44: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
45: }
46: v = 4.0;
47: MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES);
48: }
49: }
50: MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY);
51: MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY);
53: MatGetOrdering(C, MATORDERINGND, &rperm, &cperm);
54: ISView(rperm, PETSC_VIEWER_STDOUT_SELF);
55: ISDestroy(&rperm);
56: ISDestroy(&cperm);
58: MatGetOrdering(C, MATORDERINGRCM, &rperm, &cperm);
59: ISView(rperm, PETSC_VIEWER_STDOUT_SELF);
60: ISDestroy(&rperm);
61: ISDestroy(&cperm);
63: MatGetOrdering(C, MATORDERINGQMD, &rperm, &cperm);
64: ISView(rperm, PETSC_VIEWER_STDOUT_SELF);
65: ISDestroy(&rperm);
66: ISDestroy(&cperm);
68: /* create Cperm = rperm*C*icperm */
69: PetscOptionsGetBool(NULL, NULL, "-testmyordering", &TestMyorder, NULL);
70: if (TestMyorder) {
71: MatGetOrdering_myordering(C, MATORDERINGQMD, &rperm, &cperm);
72: printf("myordering's rperm:\n");
73: ISView(rperm, PETSC_VIEWER_STDOUT_SELF);
74: ISInvertPermutation(cperm, PETSC_DECIDE, &icperm);
75: ISGetIndices(rperm, &rperm_ptr);
76: ISGetIndices(icperm, &cperm_ptr);
77: MatCreateSeqAIJ(PETSC_COMM_SELF, m * n, m * n, 5, NULL, &Cperm);
78: for (i = 0; i < m * n; i++) {
79: MatGetRow(C, rperm_ptr[i], &ncols, &cols, &vals);
80: for (j = 0; j < ncols; j++) {
81: /* printf(" (%d %d %g)\n",i,cperm_ptr[cols[j]],vals[j]); */
82: MatSetValues(Cperm, 1, &i, 1, &cperm_ptr[cols[j]], &vals[j], INSERT_VALUES);
83: }
84: }
85: MatAssemblyBegin(Cperm, MAT_FINAL_ASSEMBLY);
86: MatAssemblyEnd(Cperm, MAT_FINAL_ASSEMBLY);
87: ISRestoreIndices(rperm, &rperm_ptr);
88: ISRestoreIndices(icperm, &cperm_ptr);
90: ISDestroy(&rperm);
91: ISDestroy(&cperm);
92: ISDestroy(&icperm);
93: MatDestroy(&Cperm);
94: }
96: MatDestroy(&C);
97: PetscFinalize();
98: return 0;
99: }
101: #include <petsc/private/matimpl.h>
102: /* This is modified from MatGetOrdering_Natural() */
103: PetscErrorCode MatGetOrdering_myordering(Mat mat, MatOrderingType type, IS *irow, IS *icol)
104: {
105: PetscInt n, i, *ii;
106: PetscBool done;
107: MPI_Comm comm;
109: PetscObjectGetComm((PetscObject)mat, &comm);
110: MatGetRowIJ(mat, 0, PETSC_FALSE, PETSC_TRUE, &n, NULL, NULL, &done);
111: MatRestoreRowIJ(mat, 0, PETSC_FALSE, PETSC_TRUE, NULL, NULL, NULL, &done);
112: if (done) { /* matrix may be "compressed" in symbolic factorization, due to i-nodes or block storage */
113: PetscMalloc1(n, &ii);
114: for (i = 0; i < n; i++) ii[i] = n - i - 1; /* replace your index here */
115: ISCreateGeneral(PETSC_COMM_SELF, n, ii, PETSC_COPY_VALUES, irow);
116: ISCreateGeneral(PETSC_COMM_SELF, n, ii, PETSC_OWN_POINTER, icol);
117: } else SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_SUP, "MatRestoreRowIJ fails!");
118: ISSetPermutation(*irow);
119: ISSetPermutation(*icol);
120: return 0;
121: }
123: /*TEST
125: test:
127: TEST*/