Actual source code: ex20.c
2: static char help[] = "Tests converting a matrix to another format with MatConvert().\n\n";
4: #include <petscmat.h>
6: int main(int argc, char **args)
7: {
8: Mat C, A;
9: PetscInt i, j, m = 5, n = 4, Ii, J;
10: PetscMPIInt rank, size;
11: PetscScalar v;
12: char mtype[256];
15: PetscInitialize(&argc, &args, (char *)0, help);
16: MPI_Comm_rank(PETSC_COMM_WORLD, &rank);
18: /* This example does not work correctly for np > 2 */
19: MPI_Comm_size(PETSC_COMM_WORLD, &size);
22: /* Create the matrix for the five point stencil, YET AGAIN */
23: MatCreate(PETSC_COMM_WORLD, &C);
24: MatSetSizes(C, PETSC_DECIDE, PETSC_DECIDE, m * n, m * n);
25: MatSetFromOptions(C);
26: MatSetUp(C);
27: for (i = 0; i < m; i++) {
28: for (j = 2 * rank; j < 2 * rank + 2; j++) {
29: v = -1.0;
30: Ii = j + n * i;
31: if (i > 0) {
32: J = Ii - n;
33: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
34: }
35: if (i < m - 1) {
36: J = Ii + n;
37: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
38: }
39: if (j > 0) {
40: J = Ii - 1;
41: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
42: }
43: if (j < n - 1) {
44: J = Ii + 1;
45: MatSetValues(C, 1, &Ii, 1, &J, &v, INSERT_VALUES);
46: }
47: v = 4.0;
48: MatSetValues(C, 1, &Ii, 1, &Ii, &v, INSERT_VALUES);
49: }
50: }
52: MatAssemblyBegin(C, MAT_FINAL_ASSEMBLY);
53: MatAssemblyEnd(C, MAT_FINAL_ASSEMBLY);
54: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO);
55: MatView(C, PETSC_VIEWER_STDOUT_WORLD);
56: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
57: MatView(C, PETSC_VIEWER_STDOUT_WORLD);
59: PetscStrcpy(mtype, MATSAME);
60: PetscOptionsGetString(NULL, NULL, "-conv_mat_type", mtype, sizeof(mtype), NULL);
61: MatConvert(C, mtype, MAT_INITIAL_MATRIX, &A);
62: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO);
63: MatView(A, PETSC_VIEWER_STDOUT_WORLD);
64: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
65: PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_IMPL);
66: MatView(A, PETSC_VIEWER_STDOUT_WORLD);
67: PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD);
69: /* Free data structures */
70: MatDestroy(&A);
71: MatDestroy(&C);
73: PetscFinalize();
74: return 0;
75: }
77: /*TEST
79: test:
80: args: -conv_mat_type seqaij
82: TEST*/