Actual source code: ex51.c
1: static char help[] = "Tests DMDAGlobalToNaturalAllCreate() using contour plotting for 2d DMDAs.\n\n";
3: #include <petscdm.h>
4: #include <petscdmda.h>
5: #include <petscdraw.h>
7: int main(int argc, char **argv)
8: {
9: PetscInt i, j, M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE;
10: PetscMPIInt rank;
11: PetscBool flg = PETSC_FALSE;
12: DM da;
13: PetscViewer viewer;
14: Vec localall, global;
15: PetscScalar value, *vlocal;
16: DMBoundaryType bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE;
17: DMDAStencilType stype = DMDA_STENCIL_BOX;
18: VecScatter tolocalall, fromlocalall;
19: PetscInt start, end;
21: PetscFunctionBeginUser;
22: PetscCall(PetscInitialize(&argc, &argv, NULL, help));
23: PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer));
25: /* Read options */
26: PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
27: PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
28: PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
29: PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
30: PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL));
31: if (flg) stype = DMDA_STENCIL_STAR;
33: /* Create distributed array and get vectors */
34: PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, m, n, 1, 1, NULL, NULL, &da));
35: PetscCall(DMSetFromOptions(da));
36: PetscCall(DMSetUp(da));
38: PetscCall(DMCreateGlobalVector(da, &global));
39: PetscCall(VecCreateSeq(PETSC_COMM_SELF, M * N, &localall));
41: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
42: PetscCall(VecGetOwnershipRange(global, &start, &end));
43: for (i = start; i < end; i++) {
44: value = 5.0 * rank;
45: PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES));
46: }
47: PetscCall(VecAssemblyBegin(global));
48: PetscCall(VecAssemblyEnd(global));
49: PetscCall(VecView(global, viewer));
51: /*
52: Create Scatter from global DMDA parallel vector to local vector that
53: contains all entries
54: */
55: PetscCall(DMDAGlobalToNaturalAllCreate(da, &tolocalall));
56: PetscCall(DMDANaturalAllToGlobalCreate(da, &fromlocalall));
58: PetscCall(VecScatterBegin(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
59: PetscCall(VecScatterEnd(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
61: PetscCall(VecGetArray(localall, &vlocal));
62: for (j = 0; j < N; j++) {
63: for (i = 0; i < M; i++) *vlocal++ += i + j * M;
64: }
65: PetscCall(VecRestoreArray(localall, &vlocal));
67: /* scatter back to global vector */
68: PetscCall(VecScatterBegin(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
69: PetscCall(VecScatterEnd(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
71: PetscCall(VecView(global, viewer));
73: /* Free memory */
74: PetscCall(VecScatterDestroy(&tolocalall));
75: PetscCall(VecScatterDestroy(&fromlocalall));
76: PetscCall(PetscViewerDestroy(&viewer));
77: PetscCall(VecDestroy(&localall));
78: PetscCall(VecDestroy(&global));
79: PetscCall(DMDestroy(&da));
80: PetscCall(PetscFinalize());
81: return 0;
82: }
84: /*TEST
86: build:
87: requires: !complex
89: test:
90: nsize: 3
92: TEST*/