Actual source code: ex51.c
2: static char help[] = "Tests DMDAGlobalToNaturalAllCreate() using contour plotting for 2d DMDAs.\n\n";
4: #include <petscdm.h>
5: #include <petscdmda.h>
6: #include <petscdraw.h>
8: int main(int argc, char **argv)
9: {
10: PetscInt i, j, M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE;
11: PetscMPIInt rank;
12: PetscBool flg = PETSC_FALSE;
13: DM da;
14: PetscViewer viewer;
15: Vec localall, global;
16: PetscScalar value, *vlocal;
17: DMBoundaryType bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE;
18: DMDAStencilType stype = DMDA_STENCIL_BOX;
19: VecScatter tolocalall, fromlocalall;
20: PetscInt start, end;
22: PetscFunctionBeginUser;
23: PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
24: PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer));
26: /* Read options */
27: PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
28: PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
29: PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
30: PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
31: PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL));
32: if (flg) stype = DMDA_STENCIL_STAR;
34: /* Create distributed array and get vectors */
35: PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, m, n, 1, 1, NULL, NULL, &da));
36: PetscCall(DMSetFromOptions(da));
37: PetscCall(DMSetUp(da));
39: PetscCall(DMCreateGlobalVector(da, &global));
40: PetscCall(VecCreateSeq(PETSC_COMM_SELF, M * N, &localall));
42: PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
43: PetscCall(VecGetOwnershipRange(global, &start, &end));
44: for (i = start; i < end; i++) {
45: value = 5.0 * rank;
46: PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES));
47: }
48: PetscCall(VecAssemblyBegin(global));
49: PetscCall(VecAssemblyEnd(global));
50: PetscCall(VecView(global, viewer));
52: /*
53: Create Scatter from global DMDA parallel vector to local vector that
54: contains all entries
55: */
56: PetscCall(DMDAGlobalToNaturalAllCreate(da, &tolocalall));
57: PetscCall(DMDANaturalAllToGlobalCreate(da, &fromlocalall));
59: PetscCall(VecScatterBegin(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
60: PetscCall(VecScatterEnd(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
62: PetscCall(VecGetArray(localall, &vlocal));
63: for (j = 0; j < N; j++) {
64: for (i = 0; i < M; i++) *vlocal++ += i + j * M;
65: }
66: PetscCall(VecRestoreArray(localall, &vlocal));
68: /* scatter back to global vector */
69: PetscCall(VecScatterBegin(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
70: PetscCall(VecScatterEnd(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
72: PetscCall(VecView(global, viewer));
74: /* Free memory */
75: PetscCall(VecScatterDestroy(&tolocalall));
76: PetscCall(VecScatterDestroy(&fromlocalall));
77: PetscCall(PetscViewerDestroy(&viewer));
78: PetscCall(VecDestroy(&localall));
79: PetscCall(VecDestroy(&global));
80: PetscCall(DMDestroy(&da));
81: PetscCall(PetscFinalize());
82: return 0;
83: }
85: /*TEST
87: build:
88: requires: !complex
90: test:
91: nsize: 3
93: TEST*/