static char help[] = "Tests VecView()/VecLoad() for DMDA vectors (this tests DMDAGlobalToNatural()).\n\n";

#include <petscdm.h>
#include <petscdmda.h>
#include <petscviewerhdf5.h>

int main(int argc, char **argv)
{
  PetscMPIInt     rank, size;
  PetscInt        N = 6, M = 8, P = 5, dof = 1;
  PetscInt        stencil_width = 1, pt = 0, st = 0;
  PetscBool       flg2, flg3, isbinary, mpiio;
  DMBoundaryType  bx = DM_BOUNDARY_NONE, by = DM_BOUNDARY_NONE, bz = DM_BOUNDARY_NONE;
  DMDAStencilType stencil_type = DMDA_STENCIL_STAR;
  DM              da, da2;
  Vec             global1, global2;
  PetscScalar     mone = -1.0;
  PetscReal       norm;
  PetscViewer     viewer;
  PetscRandom     rdm;
#if defined(PETSC_HAVE_HDF5)
  PetscBool ishdf5;
#endif

  PetscFunctionBeginUser;
  PetscCall(PetscInitialize(&argc, &argv, NULL, help));
  PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
  PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));

  PetscCall(PetscOptionsGetInt(NULL, NULL, "-M", &M, NULL));
  PetscCall(PetscOptionsGetInt(NULL, NULL, "-N", &N, NULL));
  PetscCall(PetscOptionsGetInt(NULL, NULL, "-P", &P, NULL));
  PetscCall(PetscOptionsGetInt(NULL, NULL, "-dof", &dof, NULL));
  PetscCall(PetscOptionsGetInt(NULL, NULL, "-stencil_width", &stencil_width, NULL));
  PetscCall(PetscOptionsGetInt(NULL, NULL, "-periodic", &pt, NULL));
  if (pt == 1) bx = DM_BOUNDARY_PERIODIC;
  if (pt == 2) by = DM_BOUNDARY_PERIODIC;
  if (pt == 4) {
    bx = DM_BOUNDARY_PERIODIC;
    by = DM_BOUNDARY_PERIODIC;
  }

  PetscCall(PetscOptionsGetInt(NULL, NULL, "-stencil_type", &st, NULL));
  stencil_type = (DMDAStencilType)st;

  PetscCall(PetscOptionsHasName(NULL, NULL, "-oned", &flg2));
  PetscCall(PetscOptionsHasName(NULL, NULL, "-twod", &flg2));
  PetscCall(PetscOptionsHasName(NULL, NULL, "-threed", &flg3));

  PetscCall(PetscOptionsHasName(NULL, NULL, "-binary", &isbinary));
#if defined(PETSC_HAVE_HDF5)
  PetscCall(PetscOptionsHasName(NULL, NULL, "-hdf5", &ishdf5));
#endif
  PetscCall(PetscOptionsHasName(NULL, NULL, "-mpiio", &mpiio));
  if (flg2) {
    PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stencil_type, M, N, PETSC_DECIDE, PETSC_DECIDE, dof, stencil_width, 0, 0, &da));
  } else if (flg3) {
    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));
  } else {
    PetscCall(DMDACreate1d(PETSC_COMM_WORLD, bx, M, dof, stencil_width, NULL, &da));
  }
  PetscCall(DMSetFromOptions(da));
  PetscCall(DMSetUp(da));

  PetscCall(DMCreateGlobalVector(da, &global1));
  PetscCall(PetscObjectSetName((PetscObject)global1, "Test_Vec"));
  PetscCall(PetscRandomCreate(PETSC_COMM_WORLD, &rdm));
  PetscCall(PetscRandomSetFromOptions(rdm));
  PetscCall(VecSetRandom(global1, rdm));
  if (isbinary) {
    if (mpiio) PetscCall(PetscOptionsSetValue(NULL, "-viewer_binary_mpiio", ""));
    PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "temp", FILE_MODE_WRITE, &viewer));
#if defined(PETSC_HAVE_HDF5)
  } else if (ishdf5) {
    PetscCall(PetscViewerHDF5Open(PETSC_COMM_WORLD, "temp", FILE_MODE_WRITE, &viewer));
#endif
  } else SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_SUP, "Invalid Viewer : Run with -binary or -hdf5 option");
  PetscCall(VecView(global1, viewer));
  PetscCall(PetscViewerDestroy(&viewer));

  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Global vector written to temp file is \n"));
  PetscCall(VecView(global1, PETSC_VIEWER_STDOUT_WORLD));

  if (flg2) {
    PetscCall(DMDACreate2d(PETSC_COMM_WORLD, bx, by, stencil_type, M, N, PETSC_DECIDE, PETSC_DECIDE, dof, stencil_width, 0, 0, &da2));
  } else if (flg3) {
    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, &da2));
  } else {
    PetscCall(DMDACreate1d(PETSC_COMM_WORLD, bx, M, dof, stencil_width, NULL, &da2));
  }
  PetscCall(DMSetFromOptions(da2));
  PetscCall(DMSetUp(da2));

  if (isbinary) {
    PetscCall(PetscViewerBinaryOpen(PETSC_COMM_WORLD, "temp", FILE_MODE_READ, &viewer));
#if defined(PETSC_HAVE_HDF5)
  } else if (ishdf5) {
    PetscCall(PetscViewerHDF5Open(PETSC_COMM_WORLD, "temp", FILE_MODE_READ, &viewer));
#endif
  } else SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_SUP, "Invalid Viewer : Run with -binary or -hdf5 option");

  PetscCall(DMCreateGlobalVector(da2, &global2));
  PetscCall(PetscObjectSetName((PetscObject)global2, "Test_Vec"));
  PetscCall(VecLoad(global2, viewer));
  PetscCall(PetscViewerDestroy(&viewer));

  PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Global vector read from temp file is \n"));
  PetscCall(VecView(global2, PETSC_VIEWER_STDOUT_WORLD));
  PetscCall(VecAXPY(global2, mone, global1));
  PetscCall(VecNorm(global2, NORM_MAX, &norm));
  if (norm != 0.0) {
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "ex23: Norm of difference %g should be zero\n", (double)norm));
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "  Number of processors %d\n", size));
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "  M,N,P,dof %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT " %" PetscInt_FMT "\n", M, N, P, dof));
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "  stencil_width %" PetscInt_FMT " stencil_type %d periodic %d\n", stencil_width, (int)stencil_type, (int)pt));
    PetscCall(PetscPrintf(PETSC_COMM_WORLD, "  dimension %d\n", 1 + (int)flg2 + (int)flg3));
  }

  PetscCall(PetscRandomDestroy(&rdm));
  PetscCall(DMDestroy(&da));
  PetscCall(DMDestroy(&da2));
  PetscCall(VecDestroy(&global1));
  PetscCall(VecDestroy(&global2));
  PetscCall(PetscFinalize());
  return 0;
}