Actual source code: ex14.c

  1: static char help[] = "Tests saving DMDA vectors to files.\n\n";

  3: /*
  4:     ex13.c reads in the DMDA and vector written by this program.
  5: */

  7: #include <petscdm.h>
  8: #include <petscdmda.h>

 10: int main(int argc, char **argv)
 11: {
 12:   PetscMPIInt rank;
 13:   PetscInt    M = 10, N = 8, m = PETSC_DECIDE, n = PETSC_DECIDE, dof = 1;
 14:   DM          da;
 15:   Vec         local, global, natural;
 16:   PetscScalar value;
 17:   PetscViewer bviewer;

 19:   PetscFunctionBeginUser;
 20:   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
 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));
 25:   PetscCall(PetscOptionsGetInt(NULL, NULL, "-dof", &dof, NULL));

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

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

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

 45:   PetscCall(DMDACreateNaturalVector(da, &natural));
 46:   PetscCall(DMDAGlobalToNaturalBegin(da, global, INSERT_VALUES, natural));
 47:   PetscCall(DMDAGlobalToNaturalEnd(da, global, INSERT_VALUES, natural));

 49:   PetscCall(DMDASetFieldName(da, 0, "First field"));
 50:   /*  PetscCall(VecView(global,PETSC_VIEWER_DRAW_WORLD)); */

 52:   PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "daoutput", FILE_MODE_WRITE, &bviewer));
 53:   PetscCall(DMView(da, bviewer));
 54:   PetscCall(VecView(global, bviewer));
 55:   PetscCall(PetscViewerDestroy(&bviewer));

 57:   /* Free memory */
 58:   PetscCall(VecDestroy(&local));
 59:   PetscCall(VecDestroy(&global));
 60:   PetscCall(VecDestroy(&natural));
 61:   PetscCall(DMDestroy(&da));
 62:   PetscCall(PetscFinalize());
 63:   return 0;
 64: }