Actual source code: ex4.c
2: static char help[] = "Demonstrates various vector routines for DMDA.\n\n";
4: /*
5: Include "petscpf.h" so that we can use pf functions and "petscdmda.h" so
6: we can use the PETSc distributed arrays
7: */
9: #include <petscpf.h>
10: #include <petscdm.h>
11: #include <petscdmda.h>
13: PetscErrorCode myfunction(void *ctx, PetscInt n, const PetscScalar *xy, PetscScalar *u)
14: {
15: PetscInt i;
17: PetscFunctionBeginUser;
18: for (i = 0; i < n; i++) {
19: u[2 * i] = xy[2 * i];
20: u[2 * i + 1] = xy[2 * i + 1];
21: }
22: PetscFunctionReturn(PETSC_SUCCESS);
23: }
25: int main(int argc, char **argv)
26: {
27: Vec u, xy;
28: DM da;
29: PetscInt m = 10, n = 10, dof = 2;
30: PF pf;
32: PetscFunctionBeginUser;
33: PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
34: PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, m, n, PETSC_DECIDE, PETSC_DECIDE, dof, 1, 0, 0, &da));
35: PetscCall(DMSetFromOptions(da));
36: PetscCall(DMSetUp(da));
37: PetscCall(DMDASetUniformCoordinates(da, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0));
38: PetscCall(DMCreateGlobalVector(da, &u));
39: PetscCall(DMGetCoordinates(da, &xy));
41: PetscCall(DMDACreatePF(da, &pf));
42: PetscCall(PFSet(pf, myfunction, 0, 0, 0, 0));
43: PetscCall(PFSetFromOptions(pf));
45: PetscCall(PFApplyVec(pf, xy, u));
47: PetscCall(VecView(u, PETSC_VIEWER_DRAW_WORLD));
49: /*
50: Free work space. All PETSc objects should be destroyed when they
51: are no longer needed.
52: */
53: PetscCall(VecDestroy(&u));
54: PetscCall(PFDestroy(&pf));
55: PetscCall(DMDestroy(&da));
56: PetscCall(PetscFinalize());
57: return 0;
58: }
60: /*TEST
62: test:
64: TEST*/