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;
15: PetscInitialize(&argc, &args, (char *)0, help);
16: /* create the matrix for the five point stencil, YET AGAIN*/
17: MatCreate(PETSC_COMM_SELF, &C);
18: MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n);
19: MatSetFromOptions(C);
20: 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: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
28: }
29: if (i < m - 1) {
30: J = Ii + n;
31: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
32: }
33: if (j > 0) {
34: J = Ii - 1;
35: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
36: }
37: if (j < n - 1) {
38: J = Ii + 1;
39: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
40: }
41: v = 4.0;
42: MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES);
43: }
44: }
45: MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY);
46: MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY);
48: ISCreateStride(PETSC_COMM_SELF, (m * n) / 2, 0, 2, &isrow);
50: PetscOptionsHasName(NULL, NULL, "-keep_nonzero_pattern", &keepnonzeropattern);
51: if (keepnonzeropattern) MatSetOption(C, MAT_KEEP_NONZERO_PATTERN, PETSC_TRUE);
53: MatZeroRowsIS(C, isrow, five, 0, 0);
55: MatView(C, PETSC_VIEWER_STDOUT_SELF);
57: ISDestroy(&isrow);
58: MatDestroy(&C);
59: 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*/