Actual source code: ex11.c
2: static char help[] = "Tests the use of MatZeroRows() for uniprocessor matrices.\n\n";
4: #include <petscmat.h>
6: int main(int argc, char **args)
7: {
8: Mat C;
9: PetscInt i, j, m = 5, n = 5, Ii, J;
10: PetscScalar v, five = 5.0;
11: IS isrow;
12: PetscBool keepnonzeropattern;
14: PetscFunctionBeginUser;
15: PetscCall(PetscInitialize(&argc, &args, (char *)0, help));
16: /* create the matrix for the five point stencil, YET AGAIN*/
17: PetscCall(MatCreate(PETSC_COMM_SELF, &C));
18: PetscCall(MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n));
19: PetscCall(MatSetFromOptions(C));
20: PetscCall(MatSetUp(C));
21: for (i = 0; i < m; i++) {
22: for (j = 0; j < n; j++) {
23: v = -1.0;
24: Ii = j + n * i;
25: if (i > 0) {
26: J = Ii - n;
27: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
28: }
29: if (i < m - 1) {
30: J = Ii + n;
31: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
32: }
33: if (j > 0) {
34: J = Ii - 1;
35: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
36: }
37: if (j < n - 1) {
38: J = Ii + 1;
39: PetscCall(MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES));
40: }
41: v = 4.0;
42: PetscCall(MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES));
43: }
44: }
45: PetscCall(MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY));
46: PetscCall(MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY));
48: PetscCall(ISCreateStride(PETSC_COMM_SELF, (m * n) / 2, 0, 2, &isrow));
50: PetscCall(PetscOptionsHasName(NULL, NULL, "-keep_nonzero_pattern", &keepnonzeropattern));
51: if (keepnonzeropattern) PetscCall(MatSetOption(C, MAT_KEEP_NONZERO_PATTERN, PETSC_TRUE));
53: PetscCall(MatZeroRowsIS(C, isrow, five, 0, 0));
55: PetscCall(MatView(C, PETSC_VIEWER_STDOUT_SELF));
57: PetscCall(ISDestroy(&isrow));
58: PetscCall(MatDestroy(&C));
59: PetscCall(PetscFinalize());
60: return 0;
61: }
63: /*TEST
65: test:
67: test:
68: suffix: 2
69: args: -mat_type seqbaij -mat_block_size 5
71: test:
72: suffix: 3
73: args: -keep_nonzero_pattern
75: test:
76: suffix: 4
77: args: -keep_nonzero_pattern -mat_type seqbaij -mat_block_size 5
79: TEST*/