xref: /petsc/src/dm/tests/ex51.c (revision ad540459ab38c4a232710a68077e487eb6627fe2)
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 
89371c9d4SSatish Balay int main(int argc, char **argv) {
9c4762a1bSJed Brown   PetscInt        i, j, M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE;
10c4762a1bSJed Brown   PetscMPIInt     rank;
11c4762a1bSJed Brown   PetscBool       flg = PETSC_FALSE;
12c4762a1bSJed Brown   DM              da;
13c4762a1bSJed Brown   PetscViewer     viewer;
14c4762a1bSJed Brown   Vec             localall, global;
15c4762a1bSJed Brown   PetscScalar     value, *vlocal;
16c4762a1bSJed Brown   DMBoundaryType  bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE;
17c4762a1bSJed Brown   DMDAStencilType stype = DMDA_STENCIL_BOX;
18c4762a1bSJed Brown   VecScatter      tolocalall, fromlocalall;
19c4762a1bSJed Brown   PetscInt        start, end;
20c4762a1bSJed Brown 
21327415f7SBarry Smith   PetscFunctionBeginUser;
229566063dSJacob Faibussowitsch   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
239566063dSJacob Faibussowitsch   PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer));
24c4762a1bSJed Brown 
25c4762a1bSJed Brown   /* Read options */
269566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
279566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
289566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
299566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));
309566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL));
31c4762a1bSJed Brown   if (flg) stype = DMDA_STENCIL_STAR;
32c4762a1bSJed Brown 
33c4762a1bSJed Brown   /* Create distributed array and get vectors */
349566063dSJacob Faibussowitsch   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, m, n, 1, 1, NULL, NULL, &da));
359566063dSJacob Faibussowitsch   PetscCall(DMSetFromOptions(da));
369566063dSJacob Faibussowitsch   PetscCall(DMSetUp(da));
37c4762a1bSJed Brown 
389566063dSJacob Faibussowitsch   PetscCall(DMCreateGlobalVector(da, &global));
399566063dSJacob Faibussowitsch   PetscCall(VecCreateSeq(PETSC_COMM_SELF, M * N, &localall));
40c4762a1bSJed Brown 
419566063dSJacob Faibussowitsch   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
429566063dSJacob Faibussowitsch   PetscCall(VecGetOwnershipRange(global, &start, &end));
43c4762a1bSJed Brown   for (i = start; i < end; i++) {
44c4762a1bSJed Brown     value = 5.0 * rank;
459566063dSJacob Faibussowitsch     PetscCall(VecSetValues(global, 1, &i, &value, INSERT_VALUES));
46c4762a1bSJed Brown   }
479566063dSJacob Faibussowitsch   PetscCall(VecView(global, viewer));
48c4762a1bSJed Brown 
49c4762a1bSJed Brown   /*
50c4762a1bSJed Brown      Create Scatter from global DMDA parallel vector to local vector that
51c4762a1bSJed Brown    contains all entries
52c4762a1bSJed Brown   */
539566063dSJacob Faibussowitsch   PetscCall(DMDAGlobalToNaturalAllCreate(da, &tolocalall));
549566063dSJacob Faibussowitsch   PetscCall(DMDANaturalAllToGlobalCreate(da, &fromlocalall));
55c4762a1bSJed Brown 
569566063dSJacob Faibussowitsch   PetscCall(VecScatterBegin(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
579566063dSJacob Faibussowitsch   PetscCall(VecScatterEnd(tolocalall, global, localall, INSERT_VALUES, SCATTER_FORWARD));
58c4762a1bSJed Brown 
599566063dSJacob Faibussowitsch   PetscCall(VecGetArray(localall, &vlocal));
60c4762a1bSJed Brown   for (j = 0; j < N; j++) {
61*ad540459SPierre Jolivet     for (i = 0; i < M; i++) *vlocal++ += i + j * M;
62c4762a1bSJed Brown   }
639566063dSJacob Faibussowitsch   PetscCall(VecRestoreArray(localall, &vlocal));
64c4762a1bSJed Brown 
65c4762a1bSJed Brown   /* scatter back to global vector */
669566063dSJacob Faibussowitsch   PetscCall(VecScatterBegin(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
679566063dSJacob Faibussowitsch   PetscCall(VecScatterEnd(fromlocalall, localall, global, INSERT_VALUES, SCATTER_FORWARD));
68c4762a1bSJed Brown 
699566063dSJacob Faibussowitsch   PetscCall(VecView(global, viewer));
70c4762a1bSJed Brown 
71c4762a1bSJed Brown   /* Free memory */
729566063dSJacob Faibussowitsch   PetscCall(VecScatterDestroy(&tolocalall));
739566063dSJacob Faibussowitsch   PetscCall(VecScatterDestroy(&fromlocalall));
749566063dSJacob Faibussowitsch   PetscCall(PetscViewerDestroy(&viewer));
759566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&localall));
769566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&global));
779566063dSJacob Faibussowitsch   PetscCall(DMDestroy(&da));
789566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
79b122ec5aSJacob Faibussowitsch   return 0;
80c4762a1bSJed Brown }
81c4762a1bSJed Brown 
82c4762a1bSJed Brown /*TEST
83c4762a1bSJed Brown 
84c4762a1bSJed Brown    build:
85c4762a1bSJed Brown      requires: !complex
86c4762a1bSJed Brown 
87c4762a1bSJed Brown    test:
88c4762a1bSJed Brown       nsize: 3
89c4762a1bSJed Brown 
90c4762a1bSJed Brown TEST*/
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