Actual source code: ex38.c


  2: static char help[] = "Tests DMGlobalToLocal() for 3d DA with stencil width of 2.\n\n";

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

  7: int main(int argc, char **argv)
  8: {
  9:   PetscInt        N = 3, M = 2, P = 4, dof = 1, rstart, rend, i;
 10:   PetscInt        stencil_width = 2;
 11:   PetscMPIInt     rank;
 12:   DMBoundaryType  bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE, bz = DM_BOUNDARY_NONE;
 13:   DMDAStencilType stencil_type = DMDA_STENCIL_STAR;
 14:   DM              da;
 15:   Vec             global, local;

 17:   PetscFunctionBeginUser;
 18:   PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
 19:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
 20:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
 21:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
 22:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-P", &P, NULL));
 23:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-dof", &dof, NULL));
 24:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-stencil_width", &stencil_width, NULL));
 25:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-stencil_type", (PetscInt *)&stencil_type, NULL));

 27:   PetscCall(DMDACreate3d(PETSC_COMM_WORLD, bx, by, bz, stencil_type, M, N, P, PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE, dof, stencil_width, 0, 0, 0, &da));
 28:   PetscCall(DMSetFromOptions(da));
 29:   PetscCall(DMSetUp(da));
 30:   PetscCall(DMCreateGlobalVector(da, &global));
 31:   PetscCall(VecGetOwnershipRange(global, &rstart, &rend));
 32:   for (i = rstart; i < rend; i++) PetscCall(VecSetValue(global, i, (PetscReal)(i + 100 * rank), INSERT_VALUES));
 33:   PetscCall(VecAssemblyBegin(global));
 34:   PetscCall(VecAssemblyEnd(global));
 35:   PetscCall(DMCreateLocalVector(da, &local));
 36:   PetscCall(VecSet(local, -1));
 37:   PetscCall(DMGlobalToLocalBegin(da, global, INSERT_VALUES, local));
 38:   PetscCall(DMGlobalToLocalEnd(da, global, INSERT_VALUES, local));
 39:   if (rank == 0) PetscCall(VecView(local, 0));
 40:   PetscCall(DMDestroy(&da));
 41:   PetscCall(VecDestroy(&local));
 42:   PetscCall(VecDestroy(&global));
 43:   PetscCall(PetscFinalize());
 44:   return 0;
 45: }