Actual source code: ex19.c
2: static char help[] = "Tests DMDA with variable multiple degrees of freedom per node.\n\n";
4: /*
5: This code only compiles with gcc, since it is not ANSI C
6: */
8: #include <petscdm.h>
9: #include <petscdmda.h>
11: PetscErrorCode doit(DM da, Vec global)
12: {
13: PetscInt i, j, k, M, N, dof;
15: PetscCall(DMDAGetInfo(da, 0, &M, &N, 0, 0, 0, 0, &dof, 0, 0, 0, 0, 0));
16: {
17: struct {
18: PetscScalar inside[dof];
19: } **mystruct;
20: PetscCall(DMDAVecGetArrayRead(da, global, (void *)&mystruct));
21: for (i = 0; i < N; i++) {
22: for (j = 0; j < M; j++) {
23: for (k = 0; k < dof; k++) {
24: PetscCall(PetscPrintf(PETSC_COMM_WORLD, "%" PetscInt_FMT " %" PetscInt_FMT " %g\n", i, j, (double)mystruct[i][j].inside[0]));
26: mystruct[i][j].inside[1] = 2.1;
27: }
28: }
29: }
30: PetscCall(DMDAVecRestoreArrayRead(da, global, (void *)&mystruct));
31: }
32: PetscFunctionReturn(PETSC_SUCCESS);
33: }
35: int main(int argc, char **argv)
36: {
37: PetscInt dof = 2, M = 3, N = 3, m = PETSC_DECIDE, n = PETSC_DECIDE;
38: DM da;
39: Vec global, local;
41: PetscFunctionBeginUser;
42: PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
43: PetscCall(PetscOptionsGetInt(NULL, 0, "-dof", &dof, 0));
44: /* Create distributed array and get vectors */
45: PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, M, N, m, n, dof, 1, NULL, NULL, &da));
46: PetscCall(DMSetFromOptions(da));
47: PetscCall(DMSetUp(da));
48: PetscCall(DMCreateGlobalVector(da, &global));
49: PetscCall(DMCreateLocalVector(da, &local));
51: PetscCall(doit(da, global));
53: PetscCall(VecView(global, 0));
55: /* Free memory */
56: PetscCall(VecDestroy(&local));
57: PetscCall(VecDestroy(&global));
58: PetscCall(DMDestroy(&da));
59: PetscCall(PetscFinalize());
60: return 0;
61: }