xref: /petsc/src/dm/tutorials/ex5.c (revision 732aec7a18f2199fb53bb9a2f3aef439a834ce31)
1c4762a1bSJed Brown static char help[] = "Tests DMDAGetElements() and VecView() contour plotting for 2d DMDAs.\n\n";
2c4762a1bSJed Brown 
3c4762a1bSJed Brown #include <petscdm.h>
4c4762a1bSJed Brown #include <petscdmda.h>
5c4762a1bSJed Brown #include <petscdraw.h>
6c4762a1bSJed Brown 
main(int argc,char ** argv)7d71ae5a4SJacob Faibussowitsch int main(int argc, char **argv)
8d71ae5a4SJacob Faibussowitsch {
9c4762a1bSJed Brown   PetscInt        M = 10, N = 8, ne, nc, i;
10c4762a1bSJed Brown   const PetscInt *e;
11c4762a1bSJed Brown   PetscBool       flg = PETSC_FALSE;
12c4762a1bSJed Brown   DM              da;
13c4762a1bSJed Brown   PetscViewer     viewer;
14c4762a1bSJed Brown   Vec             local, global;
15c4762a1bSJed Brown   PetscScalar     value;
16c4762a1bSJed Brown   DMBoundaryType  bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE;
17c4762a1bSJed Brown   DMDAStencilType stype = DMDA_STENCIL_BOX;
18c4762a1bSJed Brown   PetscScalar    *lv;
19c4762a1bSJed Brown 
20327415f7SBarry Smith   PetscFunctionBeginUser;
21*c8025a54SPierre Jolivet   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
229566063dSJacob Faibussowitsch   PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer));
23c4762a1bSJed Brown 
24c4762a1bSJed Brown   /* Read options */
259566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
269566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
279566063dSJacob Faibussowitsch   PetscCall(PetscOptionsGetBool(NULL, NULL, "-star_stencil", &flg, NULL));
28c4762a1bSJed Brown   if (flg) stype = DMDA_STENCIL_STAR;
29c4762a1bSJed Brown 
30c4762a1bSJed Brown   /* Create distributed array and get vectors */
319566063dSJacob Faibussowitsch   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stype, M, N, PETSC_DECIDE, PETSC_DECIDE, 1, 1, NULL, NULL, &da));
329566063dSJacob Faibussowitsch   PetscCall(DMSetFromOptions(da));
339566063dSJacob Faibussowitsch   PetscCall(DMSetUp(da));
349566063dSJacob Faibussowitsch   PetscCall(DMCreateGlobalVector(da, &global));
359566063dSJacob Faibussowitsch   PetscCall(DMCreateLocalVector(da, &local));
36c4762a1bSJed Brown 
37c4762a1bSJed Brown   value = -3.0;
389566063dSJacob Faibussowitsch   PetscCall(VecSet(global, value));
399566063dSJacob Faibussowitsch   PetscCall(DMGlobalToLocalBegin(da, global, INSERT_VALUES, local));
409566063dSJacob Faibussowitsch   PetscCall(DMGlobalToLocalEnd(da, global, INSERT_VALUES, local));
41c4762a1bSJed Brown 
429566063dSJacob Faibussowitsch   PetscCall(DMDASetElementType(da, DMDA_ELEMENT_P1));
439566063dSJacob Faibussowitsch   PetscCall(DMDAGetElements(da, &ne, &nc, &e));
449566063dSJacob Faibussowitsch   PetscCall(VecGetArray(local, &lv));
45c4762a1bSJed Brown   for (i = 0; i < ne; i++) {
4663a3b9bcSJacob Faibussowitsch     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "i %" PetscInt_FMT " e[3*i] %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", i, e[3 * i], e[3 * i + 1], e[3 * i + 2]));
47c4762a1bSJed Brown     lv[e[3 * i]] = i;
48c4762a1bSJed Brown   }
499566063dSJacob Faibussowitsch   PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, stdout));
509566063dSJacob Faibussowitsch   PetscCall(VecRestoreArray(local, &lv));
519566063dSJacob Faibussowitsch   PetscCall(DMDARestoreElements(da, &ne, &nc, &e));
52c4762a1bSJed Brown 
539566063dSJacob Faibussowitsch   PetscCall(DMLocalToGlobalBegin(da, local, ADD_VALUES, global));
549566063dSJacob Faibussowitsch   PetscCall(DMLocalToGlobalEnd(da, local, ADD_VALUES, global));
55c4762a1bSJed Brown 
569566063dSJacob Faibussowitsch   PetscCall(DMView(da, viewer));
579566063dSJacob Faibussowitsch   PetscCall(VecView(global, viewer));
58c4762a1bSJed Brown 
59c4762a1bSJed Brown   /* Free memory */
609566063dSJacob Faibussowitsch   PetscCall(PetscViewerDestroy(&viewer));
619566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&local));
629566063dSJacob Faibussowitsch   PetscCall(VecDestroy(&global));
639566063dSJacob Faibussowitsch   PetscCall(DMDestroy(&da));
649566063dSJacob Faibussowitsch   PetscCall(PetscFinalize());
65b122ec5aSJacob Faibussowitsch   return 0;
66c4762a1bSJed Brown }
67c4762a1bSJed Brown 
68c4762a1bSJed Brown /*TEST
69c4762a1bSJed Brown 
70c4762a1bSJed Brown    test:
71c4762a1bSJed Brown      requires: x
72c4762a1bSJed Brown 
73c4762a1bSJed Brown    test:
74c4762a1bSJed Brown      suffix: 2
75c4762a1bSJed Brown      nsize: 2
76c4762a1bSJed Brown      requires: x
77c4762a1bSJed Brown 
78c4762a1bSJed Brown TEST*/
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