xref: /petsc/src/dm/tests/ex51.c (revision d71ae5a4db6382e7f06317b8d368875286fe9008)
1c4762a1bSJed Brown 
2c4762a1bSJed Brown static char help[] = "Tests DMDAGlobalToNaturalAllCreate() using contour plotting for 2d DMDAs.\n\n";
3c4762a1bSJed Brown 
4c4762a1bSJed Brown #include <petscdm.h>
5c4762a1bSJed Brown #include <petscdmda.h>
6c4762a1bSJed Brown #include <petscdraw.h>
7c4762a1bSJed Brown 
8*d71ae5a4SJacob Faibussowitsch int main(int argc, char **argv)
9*d71ae5a4SJacob Faibussowitsch {
10c4762a1bSJed Brown   PetscInt        i, j, M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE;
11c4762a1bSJed Brown   PetscMPIInt     rank;
12c4762a1bSJed Brown   PetscBool       flg = PETSC_FALSE;
13c4762a1bSJed Brown   DM              da;
14c4762a1bSJed Brown   PetscViewer     viewer;
15c4762a1bSJed Brown   Vec             localall, global;
16c4762a1bSJed Brown   PetscScalar     value, *vlocal;
17c4762a1bSJed Brown   DMBoundaryType  bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE;
18c4762a1bSJed Brown   DMDAStencilType stype = DMDA_STENCIL_BOX;
19c4762a1bSJed Brown   VecScatter      tolocalall, fromlocalall;
20c4762a1bSJed Brown   PetscInt        start, end;
21c4762a1bSJed Brown 
22327415f7SBarry Smith   PetscFunctionBeginUser;
239566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
249566063dSJacob Faibussowitsch   PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer));
25c4762a1bSJed Brown 
26c4762a1bSJed Brown   /* Read options */
279566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
289566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
299566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
309566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
319566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL));
32c4762a1bSJed Brown   if (flg) stype = DMDA_STENCIL_STAR;
33c4762a1bSJed Brown 
34c4762a1bSJed Brown   /* Create distributed array and get vectors */
359566063dSJacob Faibussowitsch   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, m, n, 1, 1, NULL, NULL, &da));
369566063dSJacob Faibussowitsch   PetscCall(DMSetFromOptions(da));
379566063dSJacob Faibussowitsch   PetscCall(DMSetUp(da));
38c4762a1bSJed Brown 
399566063dSJacob Faibussowitsch   PetscCall(DMCreateGlobalVector(da, &global));
409566063dSJacob Faibussowitsch   PetscCall(VecCreateSeq(PETSC_COMM_SELF, M * N, &localall));
41c4762a1bSJed Brown 
429566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
439566063dSJacob Faibussowitsch   PetscCall(VecGetOwnershipRange(global, &start, &end));
44c4762a1bSJed Brown   for (i = start; i < end; i++) {
45c4762a1bSJed Brown     value = 5.0 * rank;
469566063dSJacob Faibussowitsch     PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES));
47c4762a1bSJed Brown   }
489566063dSJacob Faibussowitsch   PetscCall(VecView(global, viewer));
49c4762a1bSJed Brown 
50c4762a1bSJed Brown   /*
51c4762a1bSJed Brown      Create Scatter from global DMDA parallel vector to local vector that
52c4762a1bSJed Brown    contains all entries
53c4762a1bSJed Brown   */
549566063dSJacob Faibussowitsch   PetscCall(DMDAGlobalToNaturalAllCreate(da, &tolocalall));
559566063dSJacob Faibussowitsch   PetscCall(DMDANaturalAllToGlobalCreate(da, &fromlocalall));
56c4762a1bSJed Brown 
579566063dSJacob Faibussowitsch   PetscCall(VecScatterBegin(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
589566063dSJacob Faibussowitsch   PetscCall(VecScatterEnd(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
59c4762a1bSJed Brown 
609566063dSJacob Faibussowitsch   PetscCall(VecGetArray(localall, &vlocal));
61c4762a1bSJed Brown   for (j = 0; j < N; j++) {
62ad540459SPierre Jolivet     for (i = 0; i < M; i++) *vlocal++ += i + j * M;
63c4762a1bSJed Brown   }
649566063dSJacob Faibussowitsch   PetscCall(VecRestoreArray(localall, &vlocal));
65c4762a1bSJed Brown 
66c4762a1bSJed Brown   /* scatter back to global vector */
679566063dSJacob Faibussowitsch   PetscCall(VecScatterBegin(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
689566063dSJacob Faibussowitsch   PetscCall(VecScatterEnd(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
69c4762a1bSJed Brown 
709566063dSJacob Faibussowitsch   PetscCall(VecView(global, viewer));
71c4762a1bSJed Brown 
72c4762a1bSJed Brown   /* Free memory */
739566063dSJacob Faibussowitsch   PetscCall(VecScatterDestroy(&tolocalall));
749566063dSJacob Faibussowitsch   PetscCall(VecScatterDestroy(&fromlocalall));
759566063dSJacob Faibussowitsch   PetscCall(PetscViewerDestroy(&viewer));
769566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&localall));
779566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&global));
789566063dSJacob Faibussowitsch   PetscCall(DMDestroy(&da));
799566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
80b122ec5aSJacob Faibussowitsch   return 0;
81c4762a1bSJed Brown }
82c4762a1bSJed Brown 
83c4762a1bSJed Brown /*TEST
84c4762a1bSJed Brown 
85c4762a1bSJed Brown    build:
86c4762a1bSJed Brown      requires: !complex
87c4762a1bSJed Brown 
88c4762a1bSJed Brown    test:
89c4762a1bSJed Brown       nsize: 3
90c4762a1bSJed Brown 
91c4762a1bSJed Brown TEST*/
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