#include <petsc/private/dmpleximpl.h> /*I   "petscdmplex.h"   I*/

#include <netcdf.h>
#include <exodusII.h>

#include <petsc/private/viewerimpl.h>
#include <petsc/private/viewerexodusiiimpl.h>
/*@C
  PETSC_VIEWER_EXODUSII_ - Creates an `PETSCVIEWEREXODUSII` `PetscViewer` shared by all processors in a communicator.

  Collective; No Fortran Support

  Input Parameter:
. comm - the MPI communicator to share the `PETSCVIEWEREXODUSII` `PetscViewer`

  Level: intermediate

  Note:
  Unlike almost all other PETSc routines, `PETSC_VIEWER_EXODUSII_()` does not return
  an error code.  The GLVIS PetscViewer is usually used in the form
.vb
  XXXView(XXX object, PETSC_VIEWER_EXODUSII_(comm));
.ve

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewer`, `PetscViewerExodusIIOpen()`, `PetscViewerType`, `PetscViewerCreate()`, `PetscViewerDestroy()`
@*/
PetscViewer PETSC_VIEWER_EXODUSII_(MPI_Comm comm)
{
  PetscViewer viewer;

  PetscFunctionBegin;
  PetscCallNull(PetscViewerExodusIIOpen(comm, "mesh.exo", FILE_MODE_WRITE, &viewer));
  PetscCallNull(PetscObjectRegisterDestroy((PetscObject)viewer));
  PetscFunctionReturn(viewer);
}

static PetscErrorCode PetscViewerView_ExodusII(PetscViewer v, PetscViewer viewer)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)v->data;

  PetscFunctionBegin;
  if (exo->filename) PetscCall(PetscViewerASCIIPrintf(viewer, "Filename:    %s\n", exo->filename));
  if (exo->exoid) PetscCall(PetscViewerASCIIPrintf(viewer, "exoid:       %" PetscExodusIIInt_FMT "\n", exo->exoid));
  if (exo->btype) PetscCall(PetscViewerASCIIPrintf(viewer, "IO Mode:     %d\n", exo->btype));
  if (exo->order) PetscCall(PetscViewerASCIIPrintf(viewer, "Mesh order:  %" PetscInt_FMT "\n", exo->order));
  PetscCall(PetscViewerASCIIPrintf(viewer, "Number of nodal variables:  %" PetscExodusIIInt_FMT "\n", exo->numNodalVariables));
  for (int i = 0; i < exo->numNodalVariables; i++) PetscCall(PetscViewerASCIIPrintf(viewer, "   %d: %s\n", i, exo->nodalVariableNames[i]));
  PetscCall(PetscViewerASCIIPrintf(viewer, "Number of zonal variables:  %" PetscExodusIIInt_FMT "\n", exo->numZonalVariables));
  for (int i = 0; i < exo->numZonalVariables; i++) PetscCall(PetscViewerASCIIPrintf(viewer, "   %d: %s\n", i, exo->zonalVariableNames[i]));
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerFlush_ExodusII(PetscViewer v)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)v->data;

  PetscFunctionBegin;
  if (exo->exoid >= 0) PetscCallExternal(ex_update, exo->exoid);
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerSetFromOptions_ExodusII(PetscViewer v, PetscOptionItems PetscOptionsObject)
{
  PetscFunctionBegin;
  PetscOptionsHeadBegin(PetscOptionsObject, "ExodusII PetscViewer Options");
  PetscOptionsHeadEnd();
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerDestroy_ExodusII(PetscViewer viewer)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  if (exo->exoid >= 0) PetscCallExternal(ex_close, exo->exoid);
  for (PetscInt i = 0; i < exo->numZonalVariables; i++) PetscCall(PetscFree(exo->zonalVariableNames[i]));
  PetscCall(PetscFree(exo->zonalVariableNames));
  for (PetscInt i = 0; i < exo->numNodalVariables; i++) PetscCall(PetscFree(exo->nodalVariableNames[i]));
  PetscCall(PetscFree(exo->nodalVariableNames));
  PetscCall(PetscFree(exo->filename));
  PetscCall(PetscFree(exo));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerFileSetName_C", NULL));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerFileGetName_C", NULL));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerFileSetMode_C", NULL));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerFileGetMode_C", NULL));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerGetId_C", NULL));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerGetOrder_C", NULL));
  PetscCall(PetscObjectComposeFunction((PetscObject)viewer, "PetscViewerSetOrder_C", NULL));
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerFileSetName_ExodusII(PetscViewer viewer, const char name[])
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  PetscMPIInt           rank;
  PetscExodusIIInt      CPU_word_size, IO_word_size, EXO_mode;
  MPI_Info              mpi_info = MPI_INFO_NULL;
  PetscExodusIIFloat    EXO_version;

  PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)viewer), &rank));
  CPU_word_size = sizeof(PetscReal);
  IO_word_size  = sizeof(PetscReal);

  PetscFunctionBegin;
  if (exo->exoid >= 0) {
    PetscCallExternal(ex_close, exo->exoid);
    exo->exoid = -1;
  }
  PetscCall(PetscFree(exo->filename));
  PetscCall(PetscStrallocpy(name, &exo->filename));
  switch (exo->btype) {
  case FILE_MODE_READ:
    EXO_mode = EX_READ;
    break;
  case FILE_MODE_APPEND:
  case FILE_MODE_UPDATE:
  case FILE_MODE_APPEND_UPDATE:
    /* Will fail if the file does not already exist */
    EXO_mode = EX_WRITE;
    break;
  case FILE_MODE_WRITE:
    /*
      exodus only allows writing geometry upon file creation, so we will let DMView create the file.
    */
    PetscFunctionReturn(PETSC_SUCCESS);
    break;
  default:
    SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call PetscViewerFileSetMode() before PetscViewerFileSetName()");
  }
#if defined(PETSC_USE_64BIT_INDICES)
  EXO_mode += EX_ALL_INT64_API;
#endif
  exo->exoid = ex_open_par(name, EXO_mode, &CPU_word_size, &IO_word_size, &EXO_version, PETSC_COMM_WORLD, mpi_info);
  PetscCheck(exo->exoid >= 0, PETSC_COMM_SELF, PETSC_ERR_LIB, "ex_open_par failed for %s", name);
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerFileGetName_ExodusII(PetscViewer viewer, const char *name[])
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  *name = exo->filename;
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerFileSetMode_ExodusII(PetscViewer viewer, PetscFileMode type)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  exo->btype = type;
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerFileGetMode_ExodusII(PetscViewer viewer, PetscFileMode *type)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  *type = exo->btype;
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerExodusIIGetId_ExodusII(PetscViewer viewer, PetscExodusIIInt *exoid)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  *exoid = exo->exoid;
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerExodusIIGetOrder_ExodusII(PetscViewer viewer, PetscInt *order)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  *order = exo->order;
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode PetscViewerExodusIISetOrder_ExodusII(PetscViewer viewer, PetscInt order)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  exo->order = order;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIISetZonalVariable - Sets the number of zonal variables in an ExodusII file

  Collective;

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- num    - the number of zonal variables in the ExodusII file

  Level: intermediate

  Notes:
  The ExodusII API does not allow changing the number of variables in a file so this function will return an error
  if called twice, called on a read-only file, or called on file for which the number of variables has already been specified

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIGetZonalVariable()`
@*/
PetscErrorCode PetscViewerExodusIISetZonalVariable(PetscViewer viewer, PetscExodusIIInt num)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  MPI_Comm              comm;
  PetscExodusIIInt      exoid = -1;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
  PetscCheck(exo->numZonalVariables == -1, comm, PETSC_ERR_SUP, "The number of zonal variables has already been set to %d and cannot be overwritten", exo->numZonalVariables);
  PetscCheck((exo->btype != FILE_MODE_READ) && (exo->btype != FILE_MODE_UNDEFINED), comm, PETSC_ERR_FILE_WRITE, "Cannot set the number of variables because the file is not writable");

  exo->numZonalVariables = num;
  PetscCall(PetscMalloc1(num, &exo->zonalVariableNames));
  for (int i = 0; i < num; i++) exo->zonalVariableNames[i] = NULL;
  PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
  PetscCallExternal(ex_put_variable_param, exoid, EX_ELEM_BLOCK, num);
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIISetNodalVariable - Sets the number of nodal variables in an ExodusII file

  Collective;

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- num    - the number of nodal variables in the ExodusII file

  Level: intermediate

  Notes:
  The ExodusII API does not allow changing the number of variables in a file so this function will return an error
  if called twice, called on a read-only file, or called on file for which the number of variables has already been specified

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIGetNodalVariable()`
@*/
PetscErrorCode PetscViewerExodusIISetNodalVariable(PetscViewer viewer, PetscExodusIIInt num)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  MPI_Comm              comm;
  PetscExodusIIInt      exoid = -1;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
  PetscCheck(exo->numNodalVariables == -1, comm, PETSC_ERR_SUP, "The number of nodal variables has already been set to %d and cannot be overwritten", exo->numNodalVariables);
  PetscCheck((exo->btype != FILE_MODE_READ) && (exo->btype != FILE_MODE_UNDEFINED), comm, PETSC_ERR_FILE_WRITE, "Cannot set the number of variables because the file is not writable");

  exo->numNodalVariables = num;
  PetscCall(PetscMalloc1(num, &exo->nodalVariableNames));
  for (int i = 0; i < num; i++) exo->nodalVariableNames[i] = NULL;
  PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
  PetscCallExternal(ex_put_variable_param, exoid, EX_NODAL, num);
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIIGetZonalVariable - Gets the number of zonal variables in an ExodusII file

  Collective

  Input Parameters:
. viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`

  Output Parameter:
. num - the number variables in the ExodusII file

  Level: intermediate

  Notes:
  The number of variables in the ExodusII file is cached in the viewer

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIsetZonalVariable()`
@*/
PetscErrorCode PetscViewerExodusIIGetZonalVariable(PetscViewer viewer, PetscExodusIIInt *num)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  MPI_Comm              comm;
  PetscExodusIIInt      exoid = -1;

  PetscFunctionBegin;
  if (exo->numZonalVariables > -1) {
    *num = exo->numZonalVariables;
  } else {
    PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
    PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
    PetscCheck(exoid > 0, comm, PETSC_ERR_FILE_OPEN, "Exodus file is not open");
    PetscCallExternal(ex_get_variable_param, exoid, EX_ELEM_BLOCK, num);
    exo->numZonalVariables = *num;
    PetscCall(PetscMalloc1(*num, &exo->zonalVariableNames));
    for (int i = 0; i < *num; i++) exo->zonalVariableNames[i] = NULL;
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIIGetNodalVariable - Gets the number of nodal variables in an ExodusII file

  Collective

  Input Parameters:
. viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`

  Output Parameter:
. num - the number variables in the ExodusII file

  Level: intermediate

  Notes:
  This function gets the number of nodal variables and saves it in the address of num.

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIISetNodalVariable()`
@*/
PetscErrorCode PetscViewerExodusIIGetNodalVariable(PetscViewer viewer, PetscExodusIIInt *num)
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  MPI_Comm              comm;
  PetscExodusIIInt      exoid = -1;

  PetscFunctionBegin;
  if (exo->numNodalVariables > -1) {
    *num = exo->numNodalVariables;
  } else {
    PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
    PetscCall(PetscObjectGetComm((PetscObject)viewer, &comm));
    PetscCheck(exoid > 0, comm, PETSC_ERR_FILE_OPEN, "Exodus file is not open");
    PetscCallExternal(ex_get_variable_param, exoid, EX_NODAL, num);
    exo->numNodalVariables = *num;
    PetscCall(PetscMalloc1(*num, &exo->nodalVariableNames));
    for (int i = 0; i < *num; i++) exo->nodalVariableNames[i] = NULL;
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIISetZonalVariableName - Sets the name of a zonal variable.

  Collective;

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
. idx    - the index for which you want to save the name
- name   - string containing the name characters

  Level: intermediate

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIGetZonalVariableName()`
@*/
PetscErrorCode PetscViewerExodusIISetZonalVariableName(PetscViewer viewer, PetscExodusIIInt idx, const char name[])
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  PetscCheck((idx >= 0) && (idx < exo->numZonalVariables), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Variable index out of range. Was PetscViewerExodusIISetZonalVariable called?");
  PetscCall(PetscStrallocpy(name, (char **)&exo->zonalVariableNames[idx]));
  PetscCallExternal(ex_put_variable_name, exo->exoid, EX_ELEM_BLOCK, idx + 1, name);
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIISetNodalVariableName - Sets the name of a nodal variable.

  Collective;

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
. idx    - the index for which you want to save the name
- name   - string containing the name characters

  Level: intermediate

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIGetNodalVariableName()`
@*/
PetscErrorCode PetscViewerExodusIISetNodalVariableName(PetscViewer viewer, PetscExodusIIInt idx, const char name[])
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  PetscCheck((idx >= 0) && (idx < exo->numNodalVariables), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Variable index out of range. Was PetscViewerExodusIISetNodalVariable called?");
  PetscCall(PetscStrallocpy(name, (char **)&exo->nodalVariableNames[idx]));
  PetscCallExternal(ex_put_variable_name, exo->exoid, EX_NODAL, idx + 1, name);
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIIGetZonalVariableName - Gets the name of a zonal variable.

  Collective;

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- idx    - the index for which you want to get the name

  Output Parameter:
. name - pointer to the string containing the name characters

  Level: intermediate

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIISetZonalVariableName()`
@*/
PetscErrorCode PetscViewerExodusIIGetZonalVariableName(PetscViewer viewer, PetscExodusIIInt idx, const char *name[])
{
  PetscViewer_ExodusII *exo   = (PetscViewer_ExodusII *)viewer->data;
  PetscExodusIIInt      exoid = -1;
  char                  tmpName[MAX_NAME_LENGTH + 1];

  PetscFunctionBegin;
  PetscCheck(idx >= 0 && idx < exo->numZonalVariables, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Variable index out of range. Was PetscViewerExodusIISetZonalVariable called?");
  if (!exo->zonalVariableNames[idx]) {
    PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
    PetscCallExternal(ex_get_variable_name, exoid, EX_ELEM_BLOCK, idx + 1, tmpName);
    PetscCall(PetscStrallocpy(tmpName, (char **)&exo->zonalVariableNames[idx]));
  }
  *name = exo->zonalVariableNames[idx];
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIIGetNodalVariableName - Gets the name of a nodal variable.

  Collective;

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- idx    - the index for which you want to save the name

  Output Parameter:
. name - string array containing name characters

  Level: intermediate

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIISetNodalVariableName()`
@*/
PetscErrorCode PetscViewerExodusIIGetNodalVariableName(PetscViewer viewer, PetscExodusIIInt idx, const char *name[])
{
  PetscViewer_ExodusII *exo   = (PetscViewer_ExodusII *)viewer->data;
  PetscExodusIIInt      exoid = -1;
  char                  tmpName[MAX_NAME_LENGTH + 1];

  PetscFunctionBegin;
  PetscCheck((idx >= 0) && (idx < exo->numNodalVariables), PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Variable index out of range. Was PetscViewerExodusIISetNodalVariable called?");
  if (!exo->nodalVariableNames[idx]) {
    PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
    PetscCallExternal(ex_get_variable_name, exoid, EX_NODAL, idx + 1, tmpName);
    PetscCall(PetscStrallocpy(tmpName, (char **)&exo->nodalVariableNames[idx]));
  }
  *name = exo->nodalVariableNames[idx];
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscViewerExodusIISetZonalVariableNames - Sets the names of all nodal variables

  Collective; No Fortran Support

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- names  - an array of string names to be set, the strings are copied into the `PetscViewer`

  Level: intermediate

  Notes:
  This function allows users to set multiple zonal variable names at a time.

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIGetZonalVariableNames()`
@*/
PetscErrorCode PetscViewerExodusIISetZonalVariableNames(PetscViewer viewer, const char *const names[])
{
  PetscExodusIIInt      numNames;
  PetscExodusIIInt      exoid = -1;
  PetscViewer_ExodusII *exo   = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  PetscCall(PetscViewerExodusIIGetZonalVariable(viewer, &numNames));
  PetscCheck(numNames >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of zonal variables not set. Was PetscViewerExodusIISetZonalVariable called?");

  PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
  for (int i = 0; i < numNames; i++) {
    PetscCall(PetscStrallocpy(names[i], &exo->zonalVariableNames[i]));
    PetscCallExternal(ex_put_variable_name, exoid, EX_ELEM_BLOCK, i + 1, names[i]);
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscViewerExodusIISetNodalVariableNames - Sets the names of all nodal variables.

  Collective; No Fortran Support

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- names  - an array of string names to be set, the strings are copied into the `PetscViewer`

  Level: intermediate

  Notes:
  This function allows users to set multiple nodal variable names at a time.

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIIGetNodalVariableNames()`
@*/
PetscErrorCode PetscViewerExodusIISetNodalVariableNames(PetscViewer viewer, const char *const names[])
{
  PetscExodusIIInt      numNames;
  PetscExodusIIInt      exoid = -1;
  PetscViewer_ExodusII *exo   = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  PetscCall(PetscViewerExodusIIGetNodalVariable(viewer, &numNames));
  PetscCheck(numNames >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of nodal variables not set. Was PetscViewerExodusIISetNodalVariable called?");

  PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
  for (int i = 0; i < numNames; i++) {
    PetscCall(PetscStrallocpy(names[i], &exo->nodalVariableNames[i]));
    PetscCallExternal(ex_put_variable_name, exoid, EX_NODAL, i + 1, names[i]);
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscViewerExodusIIGetZonalVariableNames - Gets the names of all zonal variables.

  Collective; No Fortran Support

  Input Parameters:
+ viewer  - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- numVars - the number of zonal variable names to retrieve

  Output Parameter:
. varNames - returns an array of char pointers where the zonal variable names are

  Level: intermediate

  Notes:
  This function returns a borrowed pointer which should not be freed.

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIISetZonalVariableNames()`
@*/
PetscErrorCode PetscViewerExodusIIGetZonalVariableNames(PetscViewer viewer, PetscExodusIIInt *numVars, const char *const *varNames[])
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  PetscExodusIIInt      idx;
  char                  tmpName[MAX_NAME_LENGTH + 1];
  PetscExodusIIInt      exoid = -1;

  PetscFunctionBegin;
  PetscCall(PetscViewerExodusIIGetZonalVariable(viewer, numVars));
  /*
    Cache variable names if necessary
  */
  for (idx = 0; idx < *numVars; idx++) {
    if (!exo->zonalVariableNames[idx]) {
      PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
      PetscCallExternal(ex_get_variable_name, exoid, EX_ELEM_BLOCK, idx + 1, tmpName);
      PetscCall(PetscStrallocpy(tmpName, (char **)&exo->zonalVariableNames[idx]));
    }
  }
  *varNames = (const char *const *)exo->zonalVariableNames;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@C
  PetscViewerExodusIIGetNodalVariableNames - Gets the names of all nodal variables.

  Collective; No Fortran Support

  Input Parameters:
+ viewer  - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- numVars - the number of nodal variable names to retrieve

  Output Parameter:
. varNames - returns an array of char pointers where the nodal variable names are

  Level: intermediate

  Notes:
  This function returns a borrowed pointer which should not be freed.

.seealso: `PETSCVIEWEREXODUSII`, `PetscViewer`, `PetscViewerCreate()`, `PetscViewerDestroy()`, `PetscViewerExodusIIOpen()`, `PetscViewerSetType()`, `PetscViewerType`, `PetscViewerExodusIISetNodalVariableNames()`
@*/
PetscErrorCode PetscViewerExodusIIGetNodalVariableNames(PetscViewer viewer, PetscExodusIIInt *numVars, const char *const *varNames[])
{
  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;
  PetscExodusIIInt      idx;
  char                  tmpName[MAX_NAME_LENGTH + 1];
  PetscExodusIIInt      exoid = -1;

  PetscFunctionBegin;
  PetscCall(PetscViewerExodusIIGetNodalVariable(viewer, numVars));
  /*
    Cache variable names if necessary
  */
  for (idx = 0; idx < *numVars; idx++) {
    if (!exo->nodalVariableNames[idx]) {
      PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
      PetscCallExternal(ex_get_variable_name, exoid, EX_NODAL, idx + 1, tmpName);
      PetscCall(PetscStrallocpy(tmpName, (char **)&exo->nodalVariableNames[idx]));
    }
  }
  *varNames = (const char *const *)exo->nodalVariableNames;
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*MC
   PETSCVIEWEREXODUSII - A viewer that writes to an Exodus II file

  Level: beginner

.seealso: `PetscViewerExodusIIOpen()`, `PetscViewerCreate()`, `PETSCVIEWERBINARY`, `PETSCVIEWERHDF5`, `DMView()`,
          `PetscViewerFileSetName()`, `PetscViewerFileSetMode()`, `PetscViewerFormat`, `PetscViewerType`, `PetscViewerSetType()`
M*/
PETSC_EXTERN PetscErrorCode PetscViewerCreate_ExodusII(PetscViewer v)
{
  PetscViewer_ExodusII *exo;

  PetscFunctionBegin;
  PetscCall(PetscNew(&exo));

  v->data                 = (void *)exo;
  v->ops->destroy         = PetscViewerDestroy_ExodusII;
  v->ops->setfromoptions  = PetscViewerSetFromOptions_ExodusII;
  v->ops->view            = PetscViewerView_ExodusII;
  v->ops->flush           = PetscViewerFlush_ExodusII;
  exo->btype              = FILE_MODE_UNDEFINED;
  exo->filename           = 0;
  exo->exoid              = -1;
  exo->numNodalVariables  = -1;
  exo->numZonalVariables  = -1;
  exo->nodalVariableNames = NULL;
  exo->zonalVariableNames = NULL;

  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerFileSetName_C", PetscViewerFileSetName_ExodusII));
  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerFileGetName_C", PetscViewerFileGetName_ExodusII));
  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerFileSetMode_C", PetscViewerFileSetMode_ExodusII));
  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerFileGetMode_C", PetscViewerFileGetMode_ExodusII));
  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerGetId_C", PetscViewerExodusIIGetId_ExodusII));
  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerSetOrder_C", PetscViewerExodusIISetOrder_ExodusII));
  PetscCall(PetscObjectComposeFunction((PetscObject)v, "PetscViewerGetOrder_C", PetscViewerExodusIIGetOrder_ExodusII));
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIIGetNodalVariableIndex - return the location of a nodal variable in an ExodusII file given its name

  Collective

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- name   - the name of the result

  Output Parameter:
. varIndex - the location of the variable in the exodus file or -1 if the variable is not found

  Level: beginner

  Notes:
  The exodus variable index is obtained by comparing the name argument to the
  names of zonal variables declared in the exodus file. For instance if name is "V"
  the location in the exodus file will be the first match of "V", "V_X", "V_XX", "V_1", or "V_11"
  amongst all variables of type obj_type.

.seealso: `PetscViewerExodusIISetNodalVariable()`, `PetscViewerExodusIIGetNodalVariable()`, `PetscViewerExodusIISetNodalVariableName()`, `PetscViewerExodusIISetNodalVariableNames()`, `PetscViewerExodusIIGetNodalVariableName()`, `PetscViewerExodusIIGetNodalVariableNames()`
@*/
PetscErrorCode PetscViewerExodusIIGetNodalVariableIndex(PetscViewer viewer, const char name[], PetscExodusIIInt *varIndex)
{
  PetscExodusIIInt   num_vars = 0, i, j;
  char               ext_name[MAX_STR_LENGTH + 1];
  const char *const *var_names;
  const int          num_suffix = 5;
  char              *suffix[5];
  PetscBool          flg;

  PetscFunctionBegin;
  suffix[0] = (char *)"";
  suffix[1] = (char *)"_X";
  suffix[2] = (char *)"_XX";
  suffix[3] = (char *)"_1";
  suffix[4] = (char *)"_11";
  *varIndex = -1;

  PetscCall(PetscViewerExodusIIGetNodalVariableNames(viewer, &num_vars, &var_names));
  for (i = 0; i < num_vars; ++i) {
    for (j = 0; j < num_suffix; ++j) {
      PetscCall(PetscStrncpy(ext_name, name, MAX_STR_LENGTH));
      PetscCall(PetscStrlcat(ext_name, suffix[j], MAX_STR_LENGTH));
      PetscCall(PetscStrcasecmp(ext_name, var_names[i], &flg));
      if (flg) *varIndex = i;
    }
    if (flg) break;
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  PetscViewerExodusIIGetZonalVariableIndex - return the location of a zonal variable in an ExodusII file given its name

  Collective

  Input Parameters:
+ viewer - a `PetscViewer` of type `PETSCVIEWEREXODUSII`
- name   - the name of the result

  Output Parameter:
. varIndex - the location of the variable in the exodus file or -1 if the variable is not found

  Level: beginner

  Notes:
  The exodus variable index is obtained by comparing the name argument to the
  names of zonal variables declared in the exodus file. For instance if name is "V"
  the location in the exodus file will be the first match of "V", "V_X", "V_XX", "V_1", or "V_11"
  amongst all variables of type obj_type.

.seealso: `PetscViewerExodusIISetNodalVariable()`, `PetscViewerExodusIIGetNodalVariable()`, `PetscViewerExodusIISetNodalVariableName()`, `PetscViewerExodusIISetNodalVariableNames()`, `PetscViewerExodusIIGetNodalVariableName()`, `PetscViewerExodusIIGetNodalVariableNames()`
@*/
PetscErrorCode PetscViewerExodusIIGetZonalVariableIndex(PetscViewer viewer, const char name[], int *varIndex)
{
  PetscExodusIIInt   num_vars = 0, i, j;
  char               ext_name[MAX_STR_LENGTH + 1];
  const char *const *var_names;
  const int          num_suffix = 5;
  char              *suffix[5];
  PetscBool          flg;

  PetscFunctionBegin;
  suffix[0] = (char *)"";
  suffix[1] = (char *)"_X";
  suffix[2] = (char *)"_XX";
  suffix[3] = (char *)"_1";
  suffix[4] = (char *)"_11";
  *varIndex = -1;

  PetscCall(PetscViewerExodusIIGetZonalVariableNames(viewer, &num_vars, &var_names));
  for (i = 0; i < num_vars; ++i) {
    for (j = 0; j < num_suffix; ++j) {
      PetscCall(PetscStrncpy(ext_name, name, MAX_STR_LENGTH));
      PetscCall(PetscStrlcat(ext_name, suffix[j], MAX_STR_LENGTH));
      PetscCall(PetscStrcasecmp(ext_name, var_names[i], &flg));
      if (flg) *varIndex = i;
    }
    if (flg) break;
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

PetscErrorCode DMView_PlexExodusII(DM dm, PetscViewer viewer)
{
  enum ElemType {
    SEGMENT,
    TRI,
    QUAD,
    TET,
    HEX
  };
  MPI_Comm comm;
  PetscInt degree; /* the order of the mesh */
  /* Connectivity Variables */
  PetscInt cellsNotInConnectivity;
  /* Cell Sets */
  DMLabel         csLabel;
  IS              csIS;
  const PetscInt *csIdx;
  PetscInt        num_cs, cs;
  enum ElemType  *type;
  PetscBool       hasLabel;
  /* Coordinate Variables */
  DM                 cdm;
  PetscSection       coordSection;
  Vec                coord;
  PetscInt         **nodes;
  PetscInt           depth, d, dim, skipCells = 0;
  PetscInt           pStart, pEnd, p, cStart, cEnd, numCells, vStart, vEnd, numVertices, eStart, eEnd, numEdges, fStart, fEnd, numFaces, numNodes;
  PetscInt           num_vs, num_fs;
  PetscMPIInt        rank, size;
  const char        *dmName;
  PetscInt           nodesLineP1[4] = {2, 0, 0, 0};
  PetscInt           nodesLineP2[4] = {2, 0, 0, 1};
  PetscInt           nodesTriP1[4]  = {3, 0, 0, 0};
  PetscInt           nodesTriP2[4]  = {3, 3, 0, 0};
  PetscInt           nodesQuadP1[4] = {4, 0, 0, 0};
  PetscInt           nodesQuadP2[4] = {4, 4, 0, 1};
  PetscInt           nodesTetP1[4]  = {4, 0, 0, 0};
  PetscInt           nodesTetP2[4]  = {4, 6, 0, 0};
  PetscInt           nodesHexP1[4]  = {8, 0, 0, 0};
  PetscInt           nodesHexP2[4]  = {8, 12, 6, 1};
  PetscExodusIIInt   CPU_word_size, IO_word_size, EXO_mode;
  PetscExodusIIFloat EXO_version;

  PetscViewer_ExodusII *exo = (PetscViewer_ExodusII *)viewer->data;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  PetscCallMPI(MPI_Comm_size(comm, &size));

  /*
    Creating coordSection is a collective operation so we do it somewhat out of sequence
  */
  PetscCall(PetscSectionCreate(comm, &coordSection));
  PetscCall(DMGetCoordinatesLocalSetUp(dm));
  /*
    Check that all points are on rank 0 since we don't know how to save distributed DM in exodus format
  */
  PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd));
  PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
  PetscCall(DMPlexGetDepthStratum(dm, 1, &eStart, &eEnd));
  PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
  numCells    = cEnd - cStart;
  numEdges    = eEnd - eStart;
  numVertices = vEnd - vStart;
  PetscCheck(!(rank && (numCells || numEdges || numVertices)), PETSC_COMM_SELF, PETSC_ERR_SUP, "Writing distributed DM in ExodusII format not supported");
  if (rank == 0) {
    switch (exo->btype) {
    case FILE_MODE_READ:
    case FILE_MODE_APPEND:
    case FILE_MODE_UPDATE:
    case FILE_MODE_APPEND_UPDATE:
      /* ExodusII does not allow writing geometry to an existing file */
      SETERRQ(PETSC_COMM_SELF, PETSC_ERR_LIB, "cannot add geometry to existing file %s", exo->filename);
    case FILE_MODE_WRITE:
      /* Create an empty file if one already exists*/
      EXO_mode = EX_CLOBBER;
#if defined(PETSC_USE_64BIT_INDICES)
      EXO_mode += EX_ALL_INT64_API;
#endif
      CPU_word_size = sizeof(PetscReal);
      IO_word_size  = sizeof(PetscReal);
      exo->exoid    = ex_create(exo->filename, EXO_mode, &CPU_word_size, &IO_word_size);
      PetscCheck(exo->exoid >= 0, PETSC_COMM_SELF, PETSC_ERR_LIB, "ex_create failed for %s", exo->filename);

      break;
    default:
      SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ORDER, "Must call PetscViewerFileSetMode() before PetscViewerFileSetName()");
    }

    /* --- Get DM info --- */
    PetscCall(PetscObjectGetName((PetscObject)dm, &dmName));
    PetscCall(DMPlexGetDepth(dm, &depth));
    PetscCall(DMGetDimension(dm, &dim));
    PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
    if (depth == 3) {
      numFaces = fEnd - fStart;
    } else {
      numFaces = 0;
    }
    PetscCall(DMGetLabelSize(dm, "Cell Sets", &num_cs));
    PetscCall(DMGetLabelSize(dm, "Vertex Sets", &num_vs));
    PetscCall(DMGetLabelSize(dm, "Face Sets", &num_fs));
    PetscCall(DMGetCoordinatesLocal(dm, &coord));
    PetscCall(DMGetCoordinateDM(dm, &cdm));
    if (num_cs > 0) {
      PetscCall(DMGetLabel(dm, "Cell Sets", &csLabel));
      PetscCall(DMLabelGetValueIS(csLabel, &csIS));
      PetscCall(ISGetIndices(csIS, &csIdx));
    }
    PetscCall(PetscMalloc1(num_cs, &nodes));
    /* Set element type for each block and compute total number of nodes */
    PetscCall(PetscMalloc1(num_cs, &type));
    numNodes = numVertices;

    PetscCall(PetscViewerExodusIIGetOrder(viewer, &degree));
    if (degree == 2) numNodes += numEdges;
    cellsNotInConnectivity = numCells;
    for (cs = 0; cs < num_cs; ++cs) {
      IS              stratumIS;
      const PetscInt *cells;
      PetscScalar    *xyz = NULL;
      PetscInt        csSize, closureSize;

      PetscCall(DMLabelGetStratumIS(csLabel, csIdx[cs], &stratumIS));
      PetscCall(ISGetIndices(stratumIS, &cells));
      PetscCall(ISGetSize(stratumIS, &csSize));
      PetscCall(DMPlexVecGetClosure(cdm, NULL, coord, cells[0], &closureSize, &xyz));
      switch (dim) {
      case 1:
        PetscCheck(closureSize == 2 * dim, PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of vertices %" PetscInt_FMT " in dimension %" PetscInt_FMT " has no ExodusII type", closureSize / dim, dim);
        type[cs] = SEGMENT;
        break;
      case 2:
        if (closureSize == 3 * dim) {
          type[cs] = TRI;
        } else if (closureSize == 4 * dim) {
          type[cs] = QUAD;
        } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of vertices %" PetscInt_FMT " in dimension %" PetscInt_FMT " has no ExodusII type", closureSize / dim, dim);
        break;
      case 3:
        if (closureSize == 4 * dim) {
          type[cs] = TET;
        } else if (closureSize == 8 * dim) {
          type[cs] = HEX;
        } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of vertices %" PetscInt_FMT " in dimension %" PetscInt_FMT " has no ExodusII type", closureSize / dim, dim);
        break;
      default:
        SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Dimension %" PetscInt_FMT " not handled by ExodusII viewer", dim);
      }
      if ((degree == 2) && (type[cs] == SEGMENT)) numNodes += csSize;
      if ((degree == 2) && (type[cs] == QUAD)) numNodes += csSize;
      if ((degree == 2) && (type[cs] == HEX)) {
        numNodes += csSize;
        numNodes += numFaces;
      }
      PetscCall(DMPlexVecRestoreClosure(cdm, NULL, coord, cells[0], &closureSize, &xyz));
      /* Set nodes and Element type */
      if (type[cs] == SEGMENT) {
        if (degree == 1) nodes[cs] = nodesLineP1;
        else if (degree == 2) nodes[cs] = nodesLineP2;
      } else if (type[cs] == TRI) {
        if (degree == 1) nodes[cs] = nodesTriP1;
        else if (degree == 2) nodes[cs] = nodesTriP2;
      } else if (type[cs] == QUAD) {
        if (degree == 1) nodes[cs] = nodesQuadP1;
        else if (degree == 2) nodes[cs] = nodesQuadP2;
      } else if (type[cs] == TET) {
        if (degree == 1) nodes[cs] = nodesTetP1;
        else if (degree == 2) nodes[cs] = nodesTetP2;
      } else if (type[cs] == HEX) {
        if (degree == 1) nodes[cs] = nodesHexP1;
        else if (degree == 2) nodes[cs] = nodesHexP2;
      }
      /* Compute the number of cells not in the connectivity table */
      cellsNotInConnectivity -= nodes[cs][3] * csSize;

      PetscCall(ISRestoreIndices(stratumIS, &cells));
      PetscCall(ISDestroy(&stratumIS));
    }
    if (num_cs) PetscCallExternal(ex_put_init, exo->exoid, dmName, dim, numNodes, numCells, num_cs, num_vs, num_fs);
    /* --- Connectivity --- */
    for (cs = 0; cs < num_cs; ++cs) {
      IS              stratumIS;
      const PetscInt *cells;
      PetscInt       *connect, off = 0;
      PetscInt        edgesInClosure = 0, facesInClosure = 0, verticesInClosure = 0;
      PetscInt        csSize, c, connectSize, closureSize;
      char           *elem_type        = NULL;
      char            elem_type_bar2[] = "BAR2", elem_type_bar3[] = "BAR3";
      char            elem_type_tri3[] = "TRI3", elem_type_quad4[] = "QUAD4";
      char            elem_type_tri6[] = "TRI6", elem_type_quad9[] = "QUAD9";
      char            elem_type_tet4[] = "TET4", elem_type_hex8[] = "HEX8";
      char            elem_type_tet10[] = "TET10", elem_type_hex27[] = "HEX27";

      PetscCall(DMLabelGetStratumIS(csLabel, csIdx[cs], &stratumIS));
      PetscCall(ISGetIndices(stratumIS, &cells));
      PetscCall(ISGetSize(stratumIS, &csSize));
      /* Set Element type */
      if (type[cs] == SEGMENT) {
        if (degree == 1) elem_type = elem_type_bar2;
        else if (degree == 2) elem_type = elem_type_bar3;
      } else if (type[cs] == TRI) {
        if (degree == 1) elem_type = elem_type_tri3;
        else if (degree == 2) elem_type = elem_type_tri6;
      } else if (type[cs] == QUAD) {
        if (degree == 1) elem_type = elem_type_quad4;
        else if (degree == 2) elem_type = elem_type_quad9;
      } else if (type[cs] == TET) {
        if (degree == 1) elem_type = elem_type_tet4;
        else if (degree == 2) elem_type = elem_type_tet10;
      } else if (type[cs] == HEX) {
        if (degree == 1) elem_type = elem_type_hex8;
        else if (degree == 2) elem_type = elem_type_hex27;
      }
      connectSize = nodes[cs][0] + nodes[cs][1] + nodes[cs][2] + nodes[cs][3];
      PetscCall(PetscMalloc1(PetscMax(27, connectSize) * csSize, &connect));
      PetscCallExternal(ex_put_block, exo->exoid, EX_ELEM_BLOCK, csIdx[cs], elem_type, csSize, connectSize, 0, 0, 1);
      /* Find number of vertices, edges, and faces in the closure */
      verticesInClosure = nodes[cs][0];
      if (depth > 1) {
        if (dim == 2) {
          PetscCall(DMPlexGetConeSize(dm, cells[0], &edgesInClosure));
        } else if (dim == 3) {
          PetscInt *closure = NULL;

          PetscCall(DMPlexGetConeSize(dm, cells[0], &facesInClosure));
          PetscCall(DMPlexGetTransitiveClosure(dm, cells[0], PETSC_TRUE, &closureSize, &closure));
          edgesInClosure = closureSize - facesInClosure - 1 - verticesInClosure;
          PetscCall(DMPlexRestoreTransitiveClosure(dm, cells[0], PETSC_TRUE, &closureSize, &closure));
        }
      }
      /* Get connectivity for each cell */
      for (c = 0; c < csSize; ++c) {
        PetscInt *closure = NULL;
        PetscInt  temp, i;

        PetscCall(DMPlexGetTransitiveClosure(dm, cells[c], PETSC_TRUE, &closureSize, &closure));
        for (i = 0; i < connectSize; ++i) {
          if (i < nodes[cs][0]) { /* Vertices */
            connect[i + off] = closure[(i + edgesInClosure + facesInClosure + 1) * 2] + 1;
            connect[i + off] -= cellsNotInConnectivity;
          } else if (i < nodes[cs][0] + nodes[cs][1]) { /* Edges */
            connect[i + off] = closure[(i - verticesInClosure + facesInClosure + 1) * 2] + 1;
            if (nodes[cs][2] == 0) connect[i + off] -= numFaces;
            connect[i + off] -= cellsNotInConnectivity;
          } else if (i < nodes[cs][0] + nodes[cs][1] + nodes[cs][3]) { /* Cells */
            connect[i + off] = closure[0] + 1;
            connect[i + off] -= skipCells;
          } else if (i < nodes[cs][0] + nodes[cs][1] + nodes[cs][3] + nodes[cs][2]) { /* Faces */
            connect[i + off] = closure[(i - edgesInClosure - verticesInClosure) * 2] + 1;
            connect[i + off] -= cellsNotInConnectivity;
          } else {
            connect[i + off] = -1;
          }
        }
        /* Tetrahedra are inverted */
        if (type[cs] == TET) {
          temp             = connect[0 + off];
          connect[0 + off] = connect[1 + off];
          connect[1 + off] = temp;
          if (degree == 2) {
            temp             = connect[5 + off];
            connect[5 + off] = connect[6 + off];
            connect[6 + off] = temp;
            temp             = connect[7 + off];
            connect[7 + off] = connect[8 + off];
            connect[8 + off] = temp;
          }
        }
        /* Hexahedra are inverted */
        if (type[cs] == HEX) {
          temp             = connect[1 + off];
          connect[1 + off] = connect[3 + off];
          connect[3 + off] = temp;
          if (degree == 2) {
            temp              = connect[8 + off];
            connect[8 + off]  = connect[11 + off];
            connect[11 + off] = temp;
            temp              = connect[9 + off];
            connect[9 + off]  = connect[10 + off];
            connect[10 + off] = temp;
            temp              = connect[16 + off];
            connect[16 + off] = connect[17 + off];
            connect[17 + off] = temp;
            temp              = connect[18 + off];
            connect[18 + off] = connect[19 + off];
            connect[19 + off] = temp;

            temp              = connect[12 + off];
            connect[12 + off] = connect[16 + off];
            connect[16 + off] = temp;
            temp              = connect[13 + off];
            connect[13 + off] = connect[17 + off];
            connect[17 + off] = temp;
            temp              = connect[14 + off];
            connect[14 + off] = connect[18 + off];
            connect[18 + off] = temp;
            temp              = connect[15 + off];
            connect[15 + off] = connect[19 + off];
            connect[19 + off] = temp;

            temp              = connect[23 + off];
            connect[23 + off] = connect[26 + off];
            connect[26 + off] = temp;
            temp              = connect[24 + off];
            connect[24 + off] = connect[25 + off];
            connect[25 + off] = temp;
            temp              = connect[25 + off];
            connect[25 + off] = connect[26 + off];
            connect[26 + off] = temp;
          }
        }
        off += connectSize;
        PetscCall(DMPlexRestoreTransitiveClosure(dm, cells[c], PETSC_TRUE, &closureSize, &closure));
      }
      PetscCallExternal(ex_put_conn, exo->exoid, EX_ELEM_BLOCK, csIdx[cs], connect, 0, 0);
      skipCells += (nodes[cs][3] == 0) * csSize;
      PetscCall(PetscFree(connect));
      PetscCall(ISRestoreIndices(stratumIS, &cells));
      PetscCall(ISDestroy(&stratumIS));
    }
    PetscCall(PetscFree(type));
    /* --- Coordinates --- */
    PetscCall(PetscSectionSetChart(coordSection, pStart, pEnd));
    if (num_cs) {
      for (d = 0; d < depth; ++d) {
        PetscCall(DMPlexGetDepthStratum(dm, d, &pStart, &pEnd));
        for (p = pStart; p < pEnd; ++p) PetscCall(PetscSectionSetDof(coordSection, p, nodes[0][d] > 0));
      }
    }
    for (cs = 0; cs < num_cs; ++cs) {
      IS              stratumIS;
      const PetscInt *cells;
      PetscInt        csSize, c;

      PetscCall(DMLabelGetStratumIS(csLabel, csIdx[cs], &stratumIS));
      PetscCall(ISGetIndices(stratumIS, &cells));
      PetscCall(ISGetSize(stratumIS, &csSize));
      for (c = 0; c < csSize; ++c) PetscCall(PetscSectionSetDof(coordSection, cells[c], nodes[cs][3] > 0));
      PetscCall(ISRestoreIndices(stratumIS, &cells));
      PetscCall(ISDestroy(&stratumIS));
    }
    if (num_cs) {
      PetscCall(ISRestoreIndices(csIS, &csIdx));
      PetscCall(ISDestroy(&csIS));
    }
    PetscCall(PetscFree(nodes));
    PetscCall(PetscSectionSetUp(coordSection));
    if (numNodes) {
      const char  *coordNames[3] = {"x", "y", "z"};
      PetscScalar *closure, *cval;
      PetscReal   *coords;
      PetscInt     hasDof, n = 0;

      /* There can't be more than 24 values in the closure of a point for the coord coordSection */
      PetscCall(PetscCalloc3(numNodes * 3, &coords, dim, &cval, 24, &closure));
      PetscCall(DMGetCoordinatesLocalNoncollective(dm, &coord));
      PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
      for (p = pStart; p < pEnd; ++p) {
        PetscCall(PetscSectionGetDof(coordSection, p, &hasDof));
        if (hasDof) {
          PetscInt closureSize = 24, j;

          PetscCall(DMPlexVecGetClosure(cdm, NULL, coord, p, &closureSize, &closure));
          for (d = 0; d < dim; ++d) {
            cval[d] = 0.0;
            for (j = 0; j < closureSize / dim; j++) cval[d] += closure[j * dim + d];
            coords[d * numNodes + n] = PetscRealPart(cval[d]) * dim / closureSize;
          }
          ++n;
        }
      }
      PetscCallExternal(ex_put_coord, exo->exoid, &coords[0 * numNodes], &coords[1 * numNodes], &coords[2 * numNodes]);
      PetscCall(PetscFree3(coords, cval, closure));
      PetscCallExternal(ex_put_coord_names, exo->exoid, (char **)coordNames);
    }

    /* --- Node Sets/Vertex Sets --- */
    PetscCall(DMHasLabel(dm, "Vertex Sets", &hasLabel));
    if (hasLabel) {
      PetscInt        i, vs, vsSize;
      const PetscInt *vsIdx, *vertices;
      PetscInt       *nodeList;
      IS              vsIS, stratumIS;
      DMLabel         vsLabel;
      PetscCall(DMGetLabel(dm, "Vertex Sets", &vsLabel));
      PetscCall(DMLabelGetValueIS(vsLabel, &vsIS));
      PetscCall(ISGetIndices(vsIS, &vsIdx));
      for (vs = 0; vs < num_vs; ++vs) {
        PetscCall(DMLabelGetStratumIS(vsLabel, vsIdx[vs], &stratumIS));
        PetscCall(ISGetIndices(stratumIS, &vertices));
        PetscCall(ISGetSize(stratumIS, &vsSize));
        PetscCall(PetscMalloc1(vsSize, &nodeList));
        for (i = 0; i < vsSize; ++i) nodeList[i] = vertices[i] - skipCells + 1;
        PetscCallExternal(ex_put_set_param, exo->exoid, EX_NODE_SET, vsIdx[vs], vsSize, 0);
        PetscCallExternal(ex_put_set, exo->exoid, EX_NODE_SET, vsIdx[vs], nodeList, NULL);
        PetscCall(ISRestoreIndices(stratumIS, &vertices));
        PetscCall(ISDestroy(&stratumIS));
        PetscCall(PetscFree(nodeList));
      }
      PetscCall(ISRestoreIndices(vsIS, &vsIdx));
      PetscCall(ISDestroy(&vsIS));
    }
    /* --- Side Sets/Face Sets --- */
    PetscCall(DMHasLabel(dm, "Face Sets", &hasLabel));
    if (hasLabel) {
      PetscInt        i, j, fs, fsSize;
      const PetscInt *fsIdx, *faces;
      IS              fsIS, stratumIS;
      DMLabel         fsLabel;
      PetscInt        numPoints, *points;
      PetscInt        elem_list_size = 0;
      PetscInt       *elem_list, *elem_ind, *side_list;

      PetscCall(DMGetLabel(dm, "Face Sets", &fsLabel));
      /* Compute size of Node List and Element List */
      PetscCall(DMLabelGetValueIS(fsLabel, &fsIS));
      PetscCall(ISGetIndices(fsIS, &fsIdx));
      for (fs = 0; fs < num_fs; ++fs) {
        PetscCall(DMLabelGetStratumIS(fsLabel, fsIdx[fs], &stratumIS));
        PetscCall(ISGetSize(stratumIS, &fsSize));
        elem_list_size += fsSize;
        PetscCall(ISDestroy(&stratumIS));
      }
      if (num_fs) {
        PetscCall(PetscMalloc3(num_fs, &elem_ind, elem_list_size, &elem_list, elem_list_size, &side_list));
        elem_ind[0] = 0;
        for (fs = 0; fs < num_fs; ++fs) {
          PetscCall(DMLabelGetStratumIS(fsLabel, fsIdx[fs], &stratumIS));
          PetscCall(ISGetIndices(stratumIS, &faces));
          PetscCall(ISGetSize(stratumIS, &fsSize));
          /* Set Parameters */
          PetscCallExternal(ex_put_set_param, exo->exoid, EX_SIDE_SET, fsIdx[fs], fsSize, 0);
          /* Indices */
          if (fs < num_fs - 1) elem_ind[fs + 1] = elem_ind[fs] + fsSize;

          for (i = 0; i < fsSize; ++i) {
            /* Element List */
            points = NULL;
            PetscCall(DMPlexGetTransitiveClosure(dm, faces[i], PETSC_FALSE, &numPoints, &points));
            elem_list[elem_ind[fs] + i] = points[2] + 1;
            PetscCall(DMPlexRestoreTransitiveClosure(dm, faces[i], PETSC_FALSE, &numPoints, &points));

            /* Side List */
            points = NULL;
            PetscCall(DMPlexGetTransitiveClosure(dm, elem_list[elem_ind[fs] + i] - 1, PETSC_TRUE, &numPoints, &points));
            for (j = 1; j < numPoints; ++j) {
              if (points[j * 2] == faces[i]) break;
            }
            /* Convert HEX sides */
            if (numPoints == 27) {
              if (j == 1) {
                j = 5;
              } else if (j == 2) {
                j = 6;
              } else if (j == 3) {
                j = 1;
              } else if (j == 4) {
                j = 3;
              } else if (j == 5) {
                j = 2;
              } else if (j == 6) {
                j = 4;
              }
            }
            /* Convert TET sides */
            if (numPoints == 15) {
              --j;
              if (j == 0) j = 4;
            }
            side_list[elem_ind[fs] + i] = j;
            PetscCall(DMPlexRestoreTransitiveClosure(dm, elem_list[elem_ind[fs] + i] - 1, PETSC_TRUE, &numPoints, &points));
          }
          PetscCall(ISRestoreIndices(stratumIS, &faces));
          PetscCall(ISDestroy(&stratumIS));
        }
        PetscCall(ISRestoreIndices(fsIS, &fsIdx));
        PetscCall(ISDestroy(&fsIS));

        /* Put side sets */
        for (fs = 0; fs < num_fs; ++fs) PetscCallExternal(ex_put_set, exo->exoid, EX_SIDE_SET, fsIdx[fs], &elem_list[elem_ind[fs]], &side_list[elem_ind[fs]]);
        PetscCall(PetscFree3(elem_ind, elem_list, side_list));
      }
    }
    /*
      close the exodus file
    */
    ex_close(exo->exoid);
    exo->exoid = -1;
  }
  PetscCall(PetscSectionDestroy(&coordSection));

  /*
    reopen the file in parallel
  */
  EXO_mode = EX_WRITE;
#if defined(PETSC_USE_64BIT_INDICES)
  EXO_mode += EX_ALL_INT64_API;
#endif
  CPU_word_size = sizeof(PetscReal);
  IO_word_size  = sizeof(PetscReal);
  exo->exoid    = ex_open_par(exo->filename, EXO_mode, &CPU_word_size, &IO_word_size, &EXO_version, comm, MPI_INFO_NULL);
  PetscCheck(exo->exoid >= 0, PETSC_COMM_SELF, PETSC_ERR_LIB, "ex_open_par failed for %s", exo->filename);
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode VecViewPlex_ExodusII_Nodal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset);
static PetscErrorCode VecViewPlex_ExodusII_Zonal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset);
static PetscErrorCode VecLoadPlex_ExodusII_Nodal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset);
static PetscErrorCode VecLoadPlex_ExodusII_Zonal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset);

PetscErrorCode VecView_PlexExodusII_Internal(Vec v, PetscViewer viewer)
{
  DM          dm;
  MPI_Comm    comm;
  PetscMPIInt rank;

  PetscExodusIIInt exoid, offsetN = -1, offsetZ = -1;
  const char      *vecname;
  PetscInt         step;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)v, &comm));
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
  PetscCall(VecGetDM(v, &dm));
  PetscCall(PetscObjectGetName((PetscObject)v, &vecname));

  PetscCall(DMGetOutputSequenceNumber(dm, &step, NULL));
  PetscCall(PetscViewerExodusIIGetNodalVariableIndex(viewer, vecname, &offsetN));
  PetscCall(PetscViewerExodusIIGetZonalVariableIndex(viewer, vecname, &offsetZ));
  PetscCheck(!(offsetN >= 0 && offsetZ >= 0), comm, PETSC_ERR_FILE_UNEXPECTED, "Found both nodal and zonal variable %s in exodus file. ", vecname);
  if (offsetN >= 0) {
    PetscCall(VecViewPlex_ExodusII_Nodal_Internal(v, exoid, (PetscExodusIIInt)step + 1, offsetN + 1));
  } else if (offsetZ >= 0) {
    PetscCall(VecViewPlex_ExodusII_Zonal_Internal(v, exoid, (PetscExodusIIInt)step + 1, offsetZ + 1));
  } else SETERRQ(comm, PETSC_ERR_FILE_UNEXPECTED, "Could not find nodal or zonal variable %s in exodus file. ", vecname);
  PetscFunctionReturn(PETSC_SUCCESS);
}

PetscErrorCode VecLoad_PlexExodusII_Internal(Vec v, PetscViewer viewer)
{
  DM          dm;
  MPI_Comm    comm;
  PetscMPIInt rank;

  PetscExodusIIInt exoid, offsetN = 0, offsetZ = 0;
  const char      *vecname;
  PetscInt         step;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)v, &comm));
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  PetscCall(PetscViewerExodusIIGetId(viewer, &exoid));
  PetscCall(VecGetDM(v, &dm));
  PetscCall(PetscObjectGetName((PetscObject)v, &vecname));

  PetscCall(DMGetOutputSequenceNumber(dm, &step, NULL));
  PetscCall(PetscViewerExodusIIGetNodalVariableIndex(viewer, vecname, &offsetN));
  PetscCall(PetscViewerExodusIIGetZonalVariableIndex(viewer, vecname, &offsetZ));
  PetscCheck(!(offsetN >= 0 && offsetZ >= 0), comm, PETSC_ERR_FILE_UNEXPECTED, "Found both nodal and zonal variable %s in exodus file. ", vecname);
  if (offsetN >= 0) PetscCall(VecLoadPlex_ExodusII_Nodal_Internal(v, exoid, (PetscExodusIIInt)step + 1, offsetN + 1));
  else if (offsetZ >= 0) PetscCall(VecLoadPlex_ExodusII_Zonal_Internal(v, exoid, (PetscExodusIIInt)step + 1, offsetZ + 1));
  else SETERRQ(comm, PETSC_ERR_FILE_UNEXPECTED, "Could not find nodal or zonal variable %s in exodus file. ", vecname);
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode VecViewPlex_ExodusII_Nodal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset)
{
  MPI_Comm           comm;
  PetscMPIInt        size;
  DM                 dm;
  Vec                vNatural, vComp;
  const PetscScalar *varray;
  PetscInt           xs, xe, bs;
  PetscBool          useNatural;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)v, &comm));
  PetscCallMPI(MPI_Comm_size(comm, &size));
  PetscCall(VecGetDM(v, &dm));
  PetscCall(DMGetUseNatural(dm, &useNatural));
  useNatural = useNatural && size > 1 ? PETSC_TRUE : PETSC_FALSE;
  if (useNatural) {
    PetscCall(DMPlexCreateNaturalVector(dm, &vNatural));
    PetscCall(DMPlexGlobalToNaturalBegin(dm, v, vNatural));
    PetscCall(DMPlexGlobalToNaturalEnd(dm, v, vNatural));
  } else {
    vNatural = v;
  }

  /* Write local chunk of the result in the exodus file
     exodus stores each component of a vector-valued field as a separate variable.
     We assume that they are stored sequentially */
  PetscCall(VecGetOwnershipRange(vNatural, &xs, &xe));
  PetscCall(VecGetBlockSize(vNatural, &bs));
  if (bs == 1) {
    PetscCall(VecGetArrayRead(vNatural, &varray));
    PetscCallExternal(ex_put_partial_var, exoid, step, EX_NODAL, offset, 1, xs + 1, xe - xs, varray);
    PetscCall(VecRestoreArrayRead(vNatural, &varray));
  } else {
    IS       compIS;
    PetscInt c;

    PetscCall(ISCreateStride(comm, (xe - xs) / bs, xs, bs, &compIS));
    for (c = 0; c < bs; ++c) {
      PetscCall(ISStrideSetStride(compIS, (xe - xs) / bs, xs + c, bs));
      PetscCall(VecGetSubVector(vNatural, compIS, &vComp));
      PetscCall(VecGetArrayRead(vComp, &varray));
      PetscCallExternal(ex_put_partial_var, exoid, step, EX_NODAL, offset + c, 1, xs / bs + 1, (xe - xs) / bs, varray);
      PetscCall(VecRestoreArrayRead(vComp, &varray));
      PetscCall(VecRestoreSubVector(vNatural, compIS, &vComp));
    }
    PetscCall(ISDestroy(&compIS));
  }
  if (useNatural) PetscCall(VecDestroy(&vNatural));
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode VecLoadPlex_ExodusII_Nodal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset)
{
  MPI_Comm     comm;
  PetscMPIInt  size;
  DM           dm;
  Vec          vNatural, vComp;
  PetscScalar *varray;
  PetscInt     xs, xe, bs;
  PetscBool    useNatural;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)v, &comm));
  PetscCallMPI(MPI_Comm_size(comm, &size));
  PetscCall(VecGetDM(v, &dm));
  PetscCall(DMGetUseNatural(dm, &useNatural));
  useNatural = useNatural && size > 1 ? PETSC_TRUE : PETSC_FALSE;
  if (useNatural) PetscCall(DMPlexCreateNaturalVector(dm, &vNatural));
  else vNatural = v;

  /* Read local chunk from the file */
  PetscCall(VecGetOwnershipRange(vNatural, &xs, &xe));
  PetscCall(VecGetBlockSize(vNatural, &bs));
  if (bs == 1) {
    PetscCall(VecGetArray(vNatural, &varray));
    PetscCallExternal(ex_get_partial_var, exoid, step, EX_NODAL, offset, 1, xs + 1, xe - xs, varray);
    PetscCall(VecRestoreArray(vNatural, &varray));
  } else {
    IS       compIS;
    PetscInt c;

    PetscCall(ISCreateStride(comm, (xe - xs) / bs, xs, bs, &compIS));
    for (c = 0; c < bs; ++c) {
      PetscCall(ISStrideSetStride(compIS, (xe - xs) / bs, xs + c, bs));
      PetscCall(VecGetSubVector(vNatural, compIS, &vComp));
      PetscCall(VecGetArray(vComp, &varray));
      PetscCallExternal(ex_get_partial_var, exoid, step, EX_NODAL, offset + c, 1, xs / bs + 1, (xe - xs) / bs, varray);
      PetscCall(VecRestoreArray(vComp, &varray));
      PetscCall(VecRestoreSubVector(vNatural, compIS, &vComp));
    }
    PetscCall(ISDestroy(&compIS));
  }
  if (useNatural) {
    PetscCall(DMPlexNaturalToGlobalBegin(dm, vNatural, v));
    PetscCall(DMPlexNaturalToGlobalEnd(dm, vNatural, v));
    PetscCall(VecDestroy(&vNatural));
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode VecViewPlex_ExodusII_Zonal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset)
{
  MPI_Comm           comm;
  PetscMPIInt        size;
  DM                 dm;
  Vec                vNatural, vComp;
  const PetscScalar *varray;
  PetscInt           xs, xe, bs;
  PetscBool          useNatural;
  IS                 compIS;
  PetscInt          *csSize, *csID;
  PetscExodusIIInt   numCS, set, csxs = 0;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)v, &comm));
  PetscCallMPI(MPI_Comm_size(comm, &size));
  PetscCall(VecGetDM(v, &dm));
  PetscCall(DMGetUseNatural(dm, &useNatural));
  useNatural = useNatural && size > 1 ? PETSC_TRUE : PETSC_FALSE;
  if (useNatural) {
    PetscCall(DMPlexCreateNaturalVector(dm, &vNatural));
    PetscCall(DMPlexGlobalToNaturalBegin(dm, v, vNatural));
    PetscCall(DMPlexGlobalToNaturalEnd(dm, v, vNatural));
  } else {
    vNatural = v;
  }

  /* Write local chunk of the result in the exodus file
     exodus stores each component of a vector-valued field as a separate variable.
     We assume that they are stored sequentially
     Zonal variables are accessed one element block at a time, so we loop through the cell sets,
     but once the vector has been reordered to natural size, we cannot use the label information
     to figure out what to save where. */
  numCS = (PetscExodusIIInt)ex_inquire_int(exoid, EX_INQ_ELEM_BLK); // This is an int64_t
  PetscCall(PetscMalloc2(numCS, &csID, numCS, &csSize));
  PetscCallExternal(ex_get_ids, exoid, EX_ELEM_BLOCK, csID);
  for (set = 0; set < numCS; ++set) {
    ex_block block;

    block.id   = csID[set];
    block.type = EX_ELEM_BLOCK;
    PetscCallExternal(ex_get_block_param, exoid, &block);
    PetscCall(PetscIntCast(block.num_entry, &csSize[set])); // This is an int64_t
  }
  PetscCall(VecGetOwnershipRange(vNatural, &xs, &xe));
  PetscCall(VecGetBlockSize(vNatural, &bs));
  if (bs > 1) PetscCall(ISCreateStride(comm, (xe - xs) / bs, xs, bs, &compIS));
  for (set = 0; set < numCS; set++) {
    PetscInt csLocalSize, c;

    /* range of indices for set setID[set]: csxs:csxs + csSize[set]-1
       local slice of zonal values:         xs/bs,xm/bs-1
       intersection:                        max(xs/bs,csxs),min(xm/bs-1,csxs + csSize[set]-1) */
    csLocalSize = PetscMax(0, PetscMin(xe / bs, csxs + csSize[set]) - PetscMax(xs / bs, csxs));
    if (bs == 1) {
      PetscCall(VecGetArrayRead(vNatural, &varray));
      PetscCallExternal(ex_put_partial_var, exoid, step, EX_ELEM_BLOCK, offset, csID[set], PetscMax(xs - csxs, 0) + 1, csLocalSize, &varray[PetscMax(0, csxs - xs)]);
      PetscCall(VecRestoreArrayRead(vNatural, &varray));
    } else {
      for (c = 0; c < bs; ++c) {
        PetscCall(ISStrideSetStride(compIS, (xe - xs) / bs, xs + c, bs));
        PetscCall(VecGetSubVector(vNatural, compIS, &vComp));
        PetscCall(VecGetArrayRead(vComp, &varray));
        PetscCallExternal(ex_put_partial_var, exoid, step, EX_ELEM_BLOCK, offset + c, csID[set], PetscMax(xs / bs - csxs, 0) + 1, csLocalSize, &varray[PetscMax(0, csxs - xs / bs)]);
        PetscCall(VecRestoreArrayRead(vComp, &varray));
        PetscCall(VecRestoreSubVector(vNatural, compIS, &vComp));
      }
    }
    csxs += csSize[set];
  }
  PetscCall(PetscFree2(csID, csSize));
  if (bs > 1) PetscCall(ISDestroy(&compIS));
  if (useNatural) PetscCall(VecDestroy(&vNatural));
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode VecLoadPlex_ExodusII_Zonal_Internal(Vec v, PetscExodusIIInt exoid, PetscExodusIIInt step, PetscExodusIIInt offset)
{
  MPI_Comm         comm;
  PetscMPIInt      size;
  DM               dm;
  Vec              vNatural, vComp;
  PetscScalar     *varray;
  PetscInt         xs, xe, bs;
  PetscBool        useNatural;
  IS               compIS;
  PetscInt        *csSize, *csID;
  PetscExodusIIInt numCS, set, csxs = 0;

  PetscFunctionBegin;
  PetscCall(PetscObjectGetComm((PetscObject)v, &comm));
  PetscCallMPI(MPI_Comm_size(comm, &size));
  PetscCall(VecGetDM(v, &dm));
  PetscCall(DMGetUseNatural(dm, &useNatural));
  useNatural = useNatural && size > 1 ? PETSC_TRUE : PETSC_FALSE;
  if (useNatural) PetscCall(DMPlexCreateNaturalVector(dm, &vNatural));
  else vNatural = v;

  /* Read local chunk of the result in the exodus file
     exodus stores each component of a vector-valued field as a separate variable.
     We assume that they are stored sequentially
     Zonal variables are accessed one element block at a time, so we loop through the cell sets,
     but once the vector has been reordered to natural size, we cannot use the label information
     to figure out what to save where. */
  numCS = (PetscExodusIIInt)ex_inquire_int(exoid, EX_INQ_ELEM_BLK); // This is an int64_t
  PetscCall(PetscMalloc2(numCS, &csID, numCS, &csSize));
  PetscCallExternal(ex_get_ids, exoid, EX_ELEM_BLOCK, csID);
  for (set = 0; set < numCS; ++set) {
    ex_block block;

    block.id   = csID[set];
    block.type = EX_ELEM_BLOCK;
    PetscCallExternal(ex_get_block_param, exoid, &block);
    PetscCall(PetscIntCast(block.num_entry, &csSize[set])); // This is an int64_t
  }
  PetscCall(VecGetOwnershipRange(vNatural, &xs, &xe));
  PetscCall(VecGetBlockSize(vNatural, &bs));
  if (bs > 1) PetscCall(ISCreateStride(comm, (xe - xs) / bs, xs, bs, &compIS));
  for (set = 0; set < numCS; ++set) {
    PetscInt csLocalSize, c;

    /* range of indices for set setID[set]: csxs:csxs + csSize[set]-1
       local slice of zonal values:         xs/bs,xm/bs-1
       intersection:                        max(xs/bs,csxs),min(xm/bs-1,csxs + csSize[set]-1) */
    csLocalSize = PetscMax(0, PetscMin(xe / bs, csxs + csSize[set]) - PetscMax(xs / bs, csxs));
    if (bs == 1) {
      PetscCall(VecGetArray(vNatural, &varray));
      PetscCallExternal(ex_get_partial_var, exoid, step, EX_ELEM_BLOCK, offset, csID[set], PetscMax(xs - csxs, 0) + 1, csLocalSize, &varray[PetscMax(0, csxs - xs)]);
      PetscCall(VecRestoreArray(vNatural, &varray));
    } else {
      for (c = 0; c < bs; ++c) {
        PetscCall(ISStrideSetStride(compIS, (xe - xs) / bs, xs + c, bs));
        PetscCall(VecGetSubVector(vNatural, compIS, &vComp));
        PetscCall(VecGetArray(vComp, &varray));
        PetscCallExternal(ex_get_partial_var, exoid, step, EX_ELEM_BLOCK, offset + c, csID[set], PetscMax(xs / bs - csxs, 0) + 1, csLocalSize, &varray[PetscMax(0, csxs - xs / bs)]);
        PetscCall(VecRestoreArray(vComp, &varray));
        PetscCall(VecRestoreSubVector(vNatural, compIS, &vComp));
      }
    }
    csxs += csSize[set];
  }
  PetscCall(PetscFree2(csID, csSize));
  if (bs > 1) PetscCall(ISDestroy(&compIS));
  if (useNatural) {
    PetscCall(DMPlexNaturalToGlobalBegin(dm, vNatural, v));
    PetscCall(DMPlexNaturalToGlobalEnd(dm, vNatural, v));
    PetscCall(VecDestroy(&vNatural));
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}

static PetscErrorCode ExodusGetCellType_Internal(const char *elem_type, DMPolytopeType *ct)
{
  PetscBool flg;

  PetscFunctionBegin;
  *ct = DM_POLYTOPE_UNKNOWN;
  PetscCall(PetscStrcmp(elem_type, "BAR2", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_SEGMENT;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "BAR3", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_SEGMENT;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "TRI", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_TRIANGLE;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "TRI3", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_TRIANGLE;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "QUAD", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_QUADRILATERAL;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "QUAD4", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_QUADRILATERAL;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "SHELL4", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_QUADRILATERAL;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "TETRA", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_TETRAHEDRON;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "TET4", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_TETRAHEDRON;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "WEDGE", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_TRI_PRISM;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "HEX", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_HEXAHEDRON;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "HEX8", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_HEXAHEDRON;
    goto done;
  }
  PetscCall(PetscStrcmp(elem_type, "HEXAHEDRON", &flg));
  if (flg) {
    *ct = DM_POLYTOPE_HEXAHEDRON;
    goto done;
  }
  SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Unrecognized element type %s", elem_type);
done:
  PetscFunctionReturn(PETSC_SUCCESS);
}

/*@
  DMPlexCreateExodus - Create a `DMPLEX` mesh from an ExodusII file ID.

  Collective

  Input Parameters:
+ comm        - The MPI communicator
. exoid       - The ExodusII id associated with a exodus file and obtained using ex_open
- interpolate - Create faces and edges in the mesh

  Output Parameter:
. dm - The `DM` object representing the mesh

  Level: beginner

.seealso: [](ch_unstructured), `DM`, `PETSCVIEWEREXODUSII`, `DMPLEX`, `DMCreate()`
@*/
PetscErrorCode DMPlexCreateExodus(MPI_Comm comm, PetscExodusIIInt exoid, PetscBool interpolate, DM *dm)
{
  PetscMPIInt  num_proc, rank;
  DMLabel      cellSets = NULL, faceSets = NULL, vertSets = NULL;
  PetscSection coordSection;
  Vec          coordinates;
  PetscScalar *coords;
  PetscInt     coordSize, v;
  /* Read from ex_get_init() */
  char title[PETSC_MAX_PATH_LEN + 1];
  int  dim = 0, dimEmbed = 0, numVertices = 0, numCells = 0;
  int  num_cs = 0, num_vs = 0, num_fs = 0;

  PetscFunctionBegin;
  PetscCallMPI(MPI_Comm_rank(comm, &rank));
  PetscCallMPI(MPI_Comm_size(comm, &num_proc));
  PetscCall(DMCreate(comm, dm));
  PetscCall(DMSetType(*dm, DMPLEX));
  /* Open EXODUS II file and read basic information on rank 0, then broadcast to all processors */
  if (rank == 0) {
    PetscCall(PetscMemzero(title, PETSC_MAX_PATH_LEN + 1));
    PetscCallExternal(ex_get_init, exoid, title, &dimEmbed, &numVertices, &numCells, &num_cs, &num_vs, &num_fs);
    PetscCheck(num_cs, PETSC_COMM_SELF, PETSC_ERR_SUP, "Exodus file does not contain any cell set");
  }
  PetscCallMPI(MPI_Bcast(title, PETSC_MAX_PATH_LEN + 1, MPI_CHAR, 0, comm));
  PetscCallMPI(MPI_Bcast(&dim, 1, MPI_INT, 0, comm));
  PetscCall(PetscObjectSetName((PetscObject)*dm, title));
  PetscCall(DMPlexSetChart(*dm, 0, numCells + numVertices));
  /*   We do not want this label automatically computed, instead we compute it here */
  PetscCall(DMCreateLabel(*dm, "celltype"));

  /* Read cell sets information */
  if (rank == 0) {
    PetscInt *cone;
    int       c, cs, ncs, c_loc, v, v_loc;
    /* Read from ex_get_elem_blk_ids() */
    int *cs_id, *cs_order;
    /* Read from ex_get_elem_block() */
    char buffer[PETSC_MAX_PATH_LEN + 1];
    int  num_cell_in_set, num_vertex_per_cell, num_hybrid, num_attr;
    /* Read from ex_get_elem_conn() */
    int *cs_connect;

    /* Get cell sets IDs */
    PetscCall(PetscMalloc2(num_cs, &cs_id, num_cs, &cs_order));
    PetscCallExternal(ex_get_ids, exoid, EX_ELEM_BLOCK, cs_id);
    /* Read the cell set connectivity table and build mesh topology
       EXO standard requires that cells in cell sets be numbered sequentially and be pairwise disjoint. */
    /* Check for a hybrid mesh */
    for (cs = 0, num_hybrid = 0; cs < num_cs; ++cs) {
      DMPolytopeType ct;
      char           elem_type[PETSC_MAX_PATH_LEN];

      PetscCall(PetscArrayzero(elem_type, sizeof(elem_type)));
      PetscCallExternal(ex_get_elem_type, exoid, cs_id[cs], elem_type);
      PetscCall(ExodusGetCellType_Internal(elem_type, &ct));
      dim = PetscMax(dim, DMPolytopeTypeGetDim(ct));
      PetscCallExternal(ex_get_block, exoid, EX_ELEM_BLOCK, cs_id[cs], buffer, &num_cell_in_set, &num_vertex_per_cell, 0, 0, &num_attr);
      switch (ct) {
      case DM_POLYTOPE_TRI_PRISM:
        cs_order[cs] = cs;
        ++num_hybrid;
        break;
      default:
        for (c = cs; c > cs - num_hybrid; --c) cs_order[c] = cs_order[c - 1];
        cs_order[cs - num_hybrid] = cs;
      }
    }
    /* First set sizes */
    for (ncs = 0, c = 0; ncs < num_cs; ++ncs) {
      DMPolytopeType ct;
      char           elem_type[PETSC_MAX_PATH_LEN];
      const PetscInt cs = cs_order[ncs];

      PetscCall(PetscArrayzero(elem_type, sizeof(elem_type)));
      PetscCallExternal(ex_get_elem_type, exoid, cs_id[cs], elem_type);
      PetscCall(ExodusGetCellType_Internal(elem_type, &ct));
      PetscCallExternal(ex_get_block, exoid, EX_ELEM_BLOCK, cs_id[cs], buffer, &num_cell_in_set, &num_vertex_per_cell, 0, 0, &num_attr);
      for (c_loc = 0; c_loc < num_cell_in_set; ++c_loc, ++c) {
        PetscCall(DMPlexSetConeSize(*dm, c, num_vertex_per_cell));
        PetscCall(DMPlexSetCellType(*dm, c, ct));
      }
    }
    for (v = numCells; v < numCells + numVertices; ++v) PetscCall(DMPlexSetCellType(*dm, v, DM_POLYTOPE_POINT));
    PetscCall(DMSetUp(*dm));
    for (ncs = 0, c = 0; ncs < num_cs; ++ncs) {
      const PetscInt cs = cs_order[ncs];
      PetscCallExternal(ex_get_block, exoid, EX_ELEM_BLOCK, cs_id[cs], buffer, &num_cell_in_set, &num_vertex_per_cell, 0, 0, &num_attr);
      PetscCall(PetscMalloc2(num_vertex_per_cell * num_cell_in_set, &cs_connect, num_vertex_per_cell, &cone));
      PetscCallExternal(ex_get_conn, exoid, EX_ELEM_BLOCK, cs_id[cs], cs_connect, NULL, NULL);
      /* EXO uses Fortran-based indexing, DMPlex uses C-style and numbers cell first then vertices. */
      for (c_loc = 0, v = 0; c_loc < num_cell_in_set; ++c_loc, ++c) {
        DMPolytopeType ct;

        for (v_loc = 0; v_loc < num_vertex_per_cell; ++v_loc, ++v) cone[v_loc] = cs_connect[v] + numCells - 1;
        PetscCall(DMPlexGetCellType(*dm, c, &ct));
        PetscCall(DMPlexInvertCell(ct, cone));
        PetscCall(DMPlexSetCone(*dm, c, cone));
        PetscCall(DMSetLabelValue_Fast(*dm, &cellSets, "Cell Sets", c, cs_id[cs]));
      }
      PetscCall(PetscFree2(cs_connect, cone));
    }
    PetscCall(PetscFree2(cs_id, cs_order));
  }
  {
    PetscInt ints[] = {dim, dimEmbed};

    PetscCallMPI(MPI_Bcast(ints, 2, MPIU_INT, 0, comm));
    PetscCall(DMSetDimension(*dm, ints[0]));
    PetscCall(DMSetCoordinateDim(*dm, ints[1]));
    dim      = ints[0];
    dimEmbed = ints[1];
  }
  PetscCall(DMPlexSymmetrize(*dm));
  PetscCall(DMPlexStratify(*dm));
  if (interpolate) {
    DM idm;

    PetscCall(DMPlexInterpolate(*dm, &idm));
    PetscCall(DMDestroy(dm));
    *dm = idm;
  }

  /* Create vertex set label */
  if (rank == 0 && (num_vs > 0)) {
    int vs, v;
    /* Read from ex_get_node_set_ids() */
    int *vs_id;
    /* Read from ex_get_node_set_param() */
    int num_vertex_in_set;
    /* Read from ex_get_node_set() */
    int *vs_vertex_list;

    /* Get vertex set ids */
    PetscCall(PetscMalloc1(num_vs, &vs_id));
    PetscCallExternal(ex_get_ids, exoid, EX_NODE_SET, vs_id);
    for (vs = 0; vs < num_vs; ++vs) {
      PetscCallExternal(ex_get_set_param, exoid, EX_NODE_SET, vs_id[vs], &num_vertex_in_set, NULL);
      PetscCall(PetscMalloc1(num_vertex_in_set, &vs_vertex_list));
      PetscCallExternal(ex_get_set, exoid, EX_NODE_SET, vs_id[vs], vs_vertex_list, NULL);
      for (v = 0; v < num_vertex_in_set; ++v) PetscCall(DMSetLabelValue_Fast(*dm, &vertSets, "Vertex Sets", vs_vertex_list[v] + numCells - 1, vs_id[vs]));
      PetscCall(PetscFree(vs_vertex_list));
    }
    PetscCall(PetscFree(vs_id));
  }
  /* Read coordinates */
  PetscCall(DMGetCoordinateSection(*dm, &coordSection));
  PetscCall(PetscSectionSetNumFields(coordSection, 1));
  PetscCall(PetscSectionSetFieldComponents(coordSection, 0, dimEmbed));
  PetscCall(PetscSectionSetChart(coordSection, numCells, numCells + numVertices));
  for (v = numCells; v < numCells + numVertices; ++v) {
    PetscCall(PetscSectionSetDof(coordSection, v, dimEmbed));
    PetscCall(PetscSectionSetFieldDof(coordSection, v, 0, dimEmbed));
  }
  PetscCall(PetscSectionSetUp(coordSection));
  PetscCall(PetscSectionGetStorageSize(coordSection, &coordSize));
  PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
  PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
  PetscCall(VecSetSizes(coordinates, coordSize, PETSC_DETERMINE));
  PetscCall(VecSetBlockSize(coordinates, dimEmbed));
  PetscCall(VecSetType(coordinates, VECSTANDARD));
  PetscCall(VecGetArray(coordinates, &coords));
  if (rank == 0) {
    PetscReal *x, *y, *z;

    PetscCall(PetscMalloc3(numVertices, &x, numVertices, &y, numVertices, &z));
    PetscCallExternal(ex_get_coord, exoid, x, y, z);
    if (dimEmbed > 0) {
      for (v = 0; v < numVertices; ++v) coords[v * dimEmbed + 0] = x[v];
    }
    if (dimEmbed > 1) {
      for (v = 0; v < numVertices; ++v) coords[v * dimEmbed + 1] = y[v];
    }
    if (dimEmbed > 2) {
      for (v = 0; v < numVertices; ++v) coords[v * dimEmbed + 2] = z[v];
    }
    PetscCall(PetscFree3(x, y, z));
  }
  PetscCall(VecRestoreArray(coordinates, &coords));
  PetscCall(DMSetCoordinatesLocal(*dm, coordinates));
  PetscCall(VecDestroy(&coordinates));

  /* Create side set label */
  if (rank == 0 && interpolate && (num_fs > 0)) {
    int fs, f, voff;
    /* Read from ex_get_side_set_ids() */
    int *fs_id;
    /* Read from ex_get_side_set_param() */
    int num_side_in_set;
    /* Read from ex_get_side_set_node_list() */
    int *fs_vertex_count_list, *fs_vertex_list, *fs_side_list;
    /* Read side set labels */
    char   fs_name[MAX_STR_LENGTH + 1];
    size_t fs_name_len;

    /* Get side set ids */
    PetscCall(PetscMalloc1(num_fs, &fs_id));
    PetscCallExternal(ex_get_ids, exoid, EX_SIDE_SET, fs_id);
    // Ids 1 and 2 are reserved by ExodusII for indicating things in 3D
    for (fs = 0; fs < num_fs; ++fs) {
      PetscCallExternal(ex_get_set_param, exoid, EX_SIDE_SET, fs_id[fs], &num_side_in_set, NULL);
      PetscCall(PetscMalloc3(num_side_in_set, &fs_vertex_count_list, num_side_in_set * 4, &fs_vertex_list, num_side_in_set, &fs_side_list));
      PetscCallExternal(ex_get_side_set_node_list, exoid, fs_id[fs], fs_vertex_count_list, fs_vertex_list);
      PetscCallExternal(ex_get_set, exoid, EX_SIDE_SET, fs_id[fs], NULL, fs_side_list);

      /* Get the specific name associated with this side set ID. */
      int fs_name_err = ex_get_name(exoid, EX_SIDE_SET, fs_id[fs], fs_name);
      if (!fs_name_err) {
        PetscCall(PetscStrlen(fs_name, &fs_name_len));
        if (fs_name_len == 0) PetscCall(PetscStrncpy(fs_name, "Face Sets", MAX_STR_LENGTH));
      }
      for (f = 0, voff = 0; f < num_side_in_set; ++f) {
        const PetscInt *faces    = NULL;
        PetscInt        faceSize = fs_vertex_count_list[f], numFaces;
        PetscInt        faceVertices[4], v;

        PetscCheck(faceSize <= 4, comm, PETSC_ERR_ARG_WRONG, "ExodusII side cannot have %" PetscInt_FMT " > 4 vertices", faceSize);
        for (v = 0; v < faceSize; ++v, ++voff) faceVertices[v] = fs_vertex_list[voff] + numCells - 1;
        PetscCall(DMPlexGetFullJoin(*dm, faceSize, faceVertices, &numFaces, &faces));
        PetscCheck(numFaces == 1, comm, PETSC_ERR_ARG_WRONG, "Invalid ExodusII side %d in set %d maps to %" PetscInt_FMT " faces", f, fs, numFaces);
        PetscCheck(dim == 1 || faces[0] >= numCells + numVertices, comm, PETSC_ERR_ARG_WRONG, "Invalid ExodusII side %d in set %d maps to point %" PetscInt_FMT " which is not a face", f, fs, faces[0]);
        PetscCall(DMSetLabelValue_Fast(*dm, &faceSets, "Face Sets", faces[0], fs_id[fs]));
        /* Only add the label if one has been detected for this side set. */
        if (!fs_name_err) PetscCall(DMSetLabelValue(*dm, fs_name, faces[0], fs_id[fs]));
        PetscCall(DMPlexRestoreJoin(*dm, faceSize, faceVertices, &numFaces, &faces));
      }
      PetscCall(PetscFree3(fs_vertex_count_list, fs_vertex_list, fs_side_list));
    }
    PetscCall(PetscFree(fs_id));
  }

  { /* Create Cell/Face/Vertex Sets labels at all processes */
    enum {
      n = 3
    };
    PetscBool flag[n];

    flag[0] = cellSets ? PETSC_TRUE : PETSC_FALSE;
    flag[1] = faceSets ? PETSC_TRUE : PETSC_FALSE;
    flag[2] = vertSets ? PETSC_TRUE : PETSC_FALSE;
    PetscCallMPI(MPI_Bcast(flag, n, MPI_C_BOOL, 0, comm));
    if (flag[0]) PetscCall(DMCreateLabel(*dm, "Cell Sets"));
    if (flag[1]) PetscCall(DMCreateLabel(*dm, "Face Sets"));
    if (flag[2]) PetscCall(DMCreateLabel(*dm, "Vertex Sets"));
  }
  PetscFunctionReturn(PETSC_SUCCESS);
}
