Actual source code: ex1.c


  2: static char help[] = "Tests various DM routines.\n\n";

  4: #include <petscdm.h>
  5: #include <petscdmda.h>

  7: int main(int argc, char **argv)
  8: {
  9:   PetscMPIInt rank;
 10:   PetscInt    M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE;
 11:   DM          da;
 12:   PetscViewer viewer;
 13:   Vec         local, global;
 14:   PetscScalar value;

 16:   PetscFunctionBeginUser;
 17:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
 18:   PetscCall(PetscViewerDrawOpen(PETSC_COMM_WORLD, 0, "", 300, 0, 300, 300, &viewer));

 20:   /* Read options */
 21:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
 22:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
 23:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-m", &m, NULL));
 24:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-n", &n, NULL));

 26:   /* Create distributed array and get vectors */
 27:   PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, M, N, m, n, 1, 1, NULL, NULL, &da));
 28:   PetscCall(DMSetFromOptions(da));
 29:   PetscCall(DMSetUp(da));
 30:   PetscCall(DMCreateGlobalVector(da, &global));
 31:   PetscCall(DMCreateLocalVector(da, &local));

 33:   value = -3.0;
 34:   PetscCall(VecSet(global, value));
 35:   PetscCall(DMGlobalToLocalBegin(da, global, INSERT_VALUES, local));
 36:   PetscCall(DMGlobalToLocalEnd(da, global, INSERT_VALUES, local));

 38:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
 39:   value = rank + 1;
 40:   PetscCall(VecScale(local, value));
 41:   PetscCall(DMLocalToGlobalBegin(da, local, ADD_VALUES, global));
 42:   PetscCall(DMLocalToGlobalEnd(da, local, ADD_VALUES, global));

 44:   PetscCall(VecView(global, PETSC_VIEWER_STDOUT_WORLD));
 45:   PetscCall(DMView(da, viewer));

 47:   /* Free memory */
 48:   PetscCall(PetscViewerDestroy(&viewer));
 49:   PetscCall(VecDestroy(&local));
 50:   PetscCall(VecDestroy(&global));
 51:   PetscCall(DMDestroy(&da));
 52:   PetscCall(PetscFinalize());
 53:   return 0;
 54: }

 56: /*TEST

 58:    test:
 59:       nsize: 2
 60:       args: -nox
 61:       filter: grep -v -i Object

 63:    test:
 64:       suffix: cuda1
 65:       requires: cuda
 66:       args: -dm_vec_type cuda -nox
 67:       filter: grep -v -i Object

 69:    test:
 70:       suffix: cuda2
 71:       nsize: 2
 72:       requires: cuda
 73:       args: -dm_vec_type cuda -nox
 74:       filter: grep -v -i Object

 76: TEST*/