1 static char help[] = "Demonstrates various vector routines for DMDA.\n\n";
2
3 /*
4 Include "petscpf.h" so that we can use pf functions and "petscdmda.h" so
5 we can use the PETSc distributed arrays
6 */
7
8 #include <petscpf.h>
9 #include <petscdm.h>
10 #include <petscdmda.h>
11
myfunction(PetscCtx ctx,PetscInt n,const PetscScalar * xy,PetscScalar * u)12 PetscErrorCode myfunction(PetscCtx ctx, PetscInt n, const PetscScalar *xy, PetscScalar *u)
13 {
14 PetscInt i;
15
16 PetscFunctionBeginUser;
17 for (i = 0; i < n; i++) {
18 u[2 * i] = xy[2 * i];
19 u[2 * i + 1] = xy[2 * i + 1];
20 }
21 PetscFunctionReturn(PETSC_SUCCESS);
22 }
23
main(int argc,char ** argv)24 int main(int argc, char **argv)
25 {
26 Vec u, xy;
27 DM da;
28 PetscInt m = 10, n = 10, dof = 2;
29 PF pf;
30
31 PetscFunctionBeginUser;
32 PetscCall(PetscInitialize(&argc, &argv, NULL, help));
33 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));
34 PetscCall(DMSetFromOptions(da));
35 PetscCall(DMSetUp(da));
36 PetscCall(DMDASetUniformCoordinates(da, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0));
37 PetscCall(DMCreateGlobalVector(da, &u));
38 PetscCall(DMGetCoordinates(da, &xy));
39
40 PetscCall(DMDACreatePF(da, &pf));
41 PetscCall(PFSet(pf, myfunction, 0, 0, 0, 0));
42 PetscCall(PFSetFromOptions(pf));
43
44 PetscCall(PFApplyVec(pf, xy, u));
45
46 PetscCall(VecView(u, PETSC_VIEWER_DRAW_WORLD));
47
48 /*
49 Free work space. All PETSc objects should be destroyed when they
50 are no longer needed.
51 */
52 PetscCall(VecDestroy(&u));
53 PetscCall(PFDestroy(&pf));
54 PetscCall(DMDestroy(&da));
55 PetscCall(PetscFinalize());
56 return 0;
57 }
58
59 /*TEST
60
61 test:
62 output_file: output/empty.out
63
64 TEST*/
65