C++ PetscOptionsEnd函数代码示例

static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
    PetscErrorCode ierr;

    PetscFunctionBeginUser;
    options->dim           = 2;
    options->cellSimplex   = PETSC_TRUE;
    options->filename[0]   = '\0';
    options->testPartition = PETSC_TRUE;
    options->testNum       = 0;

    ierr = PetscOptionsBegin(comm, "", "Meshing Problem Options", "DMPLEX");
    CHKERRQ(ierr);
    ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex13.c", options->dim, &options->dim, NULL);
    CHKERRQ(ierr);
    ierr = PetscOptionsBool("-cell_simplex", "Use simplices if true, otherwise hexes", "ex13.c", options->cellSimplex, &options->cellSimplex, NULL);
    CHKERRQ(ierr);
    ierr = PetscOptionsString("-filename", "The mesh file", "ex13.c", options->filename, options->filename, PETSC_MAX_PATH_LEN, NULL);
    CHKERRQ(ierr);
    ierr = PetscOptionsBool("-test_partition", "Use a fixed partition for testing", "ex13.c", options->testPartition, &options->testPartition, NULL);
    CHKERRQ(ierr);
    ierr = PetscOptionsInt("-test_num", "The test partition number", "ex13.c", options->testNum, &options->testNum, NULL);
    CHKERRQ(ierr);
    ierr = PetscOptionsEnd();
    PetscFunctionReturn(0);
};

PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  PetscErrorCode ierr;

  PetscFunctionBeginUser;
  options->debug        = 0;
  options->dim          = 2;
  options->numBatches   = 1;
  options->numBlocks    = 1;
  options->showResidual = PETSC_FALSE;
  options->showResidual = PETSC_FALSE;
  options->showJacobian = PETSC_FALSE;
  options->showSolution = PETSC_TRUE;

  ierr = MPI_Comm_size(comm, &options->numProcs);CHKERRQ(ierr);
  ierr = MPI_Comm_rank(comm, &options->rank);CHKERRQ(ierr);
  ierr = PetscOptionsBegin(comm, "", "DMDA Test Problem Options", "DMDA");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-debug", "The debugging level", "ex62.c", options->debug, &options->debug, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex62.c", options->dim, &options->dim, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-gpu_batches", "The number of cell batches per kernel", "ex62.c", options->numBatches, &options->numBatches, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-gpu_blocks", "The number of concurrent blocks per kernel", "ex62.c", options->numBlocks, &options->numBlocks, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-show_initial", "Output the initial guess for verification", "ex62.c", options->showInitial, &options->showInitial, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-show_residual", "Output the residual for verification", "ex62.c", options->showResidual, &options->showResidual, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-show_jacobian", "Output the Jacobian for verification", "ex62.c", options->showJacobian, &options->showJacobian, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-show_solution", "Output the solution for verification", "ex62.c", options->showSolution, &options->showSolution, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();

  ierr = PetscLogEventRegister("Residual",            SNES_CLASSID, &options->residualEvent);CHKERRQ(ierr);
  ierr = PetscLogEventRegister("IntegResBatchCPU",    SNES_CLASSID, &options->integrateResCPUEvent);CHKERRQ(ierr);
  ierr = PetscLogEventRegister("IntegJacBatchCPU",    SNES_CLASSID, &options->integrateJacCPUEvent);CHKERRQ(ierr);
  ierr = PetscLogEventRegister("IntegJacActBatchCPU", SNES_CLASSID, &options->integrateJacActionCPUEvent);CHKERRQ(ierr);
  ierr = PetscLogEventRegister("Jacobian",            SNES_CLASSID, &options->jacobianEvent);CHKERRQ(ierr);
  PetscFunctionReturn(0);
};

static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  PetscInt dim;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  options->test         = 0;
  options->dim          = 3;
  options->simplex      = PETSC_TRUE;
  options->interpolate  = PETSC_FALSE;
  options->filename[0]  = '\0';
  ierr = PetscOptionsBegin(comm, "", "Zero-sized DMPlexGetCellFields Test Options", "DMPLEX");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-test", "Test to run", FILENAME, options->test, &options->test, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", FILENAME, options->dim, &options->dim, NULL);CHKERRQ(ierr);
  if (options->dim > 3) SETERRQ1(comm, PETSC_ERR_ARG_OUTOFRANGE, "dimension set to %d, must be <= 3", options->dim);
  ierr = PetscOptionsBool("-simplex", "Use simplices if true, otherwise hexes", FILENAME, options->simplex, &options->simplex, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-interpolate", "Interpolate the mesh", FILENAME, options->interpolate, &options->interpolate, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsString("-filename", "The mesh file", FILENAME, options->filename, options->filename, PETSC_MAX_PATH_LEN, NULL);CHKERRQ(ierr);
  options->faces[0] = 1; options->faces[1] = 1; options->faces[2] = 1;
  dim = options->dim;
  ierr = PetscOptionsIntArray("-faces", "Number of faces per dimension", FILENAME, options->faces, &dim, NULL);CHKERRQ(ierr);
  if (dim) options->dim = dim;
  ierr = PetscOptionsEnd();
  PetscFunctionReturn(0);
}

/*@
   MatFDColoringSetFromOptions - Sets coloring finite difference parameters from
   the options database.

   Collective on MatFDColoring

   The Jacobian, F'(u), is estimated with the differencing approximation
.vb
       F'(u)_{:,i} = [F(u+h*dx_{i}) - F(u)]/h where
       h = error_rel*u[i]                 if  abs(u[i]) > umin
         = +/- error_rel*umin             otherwise, with +/- determined by the sign of u[i]
       dx_{i} = (0, ... 1, .... 0)
.ve

   Input Parameter:
.  coloring - the coloring context

   Options Database Keys:
+  -mat_fd_coloring_err <err> - Sets <err> (square root of relative error in the function)
.  -mat_fd_coloring_umin <umin> - Sets umin, the minimum allowable u-value magnitude
.  -mat_fd_type - "wp" or "ds" (see MATMFFD_WP or MATMFFD_DS)
.  -mat_fd_coloring_view - Activates basic viewing
.  -mat_fd_coloring_view ::ascii_info - Activates viewing info
-  -mat_fd_coloring_view draw - Activates drawing

    Level: intermediate

.keywords: Mat, finite differences, parameters

.seealso: MatFDColoringCreate(), MatFDColoringView(), MatFDColoringSetParameters()

@*/
PetscErrorCode  MatFDColoringSetFromOptions(MatFDColoring matfd)
{
  PetscErrorCode ierr;
  PetscBool      flg;
  char           value[3];

  PetscFunctionBegin;
  PetscValidHeaderSpecific(matfd,MAT_FDCOLORING_CLASSID,1);

  ierr = PetscObjectOptionsBegin((PetscObject)matfd);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_fd_coloring_err","Square root of relative error in function","MatFDColoringSetParameters",matfd->error_rel,&matfd->error_rel,0);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-mat_fd_coloring_umin","Minimum allowable u magnitude","MatFDColoringSetParameters",matfd->umin,&matfd->umin,0);CHKERRQ(ierr);
  ierr = PetscOptionsString("-mat_fd_type","Algorithm to compute h, wp or ds","MatFDColoringCreate",matfd->htype,value,3,&flg);CHKERRQ(ierr);
  if (flg) {
    if (value[0] == 'w' && value[1] == 'p') matfd->htype = "wp";
    else if (value[0] == 'd' && value[1] == 's') matfd->htype = "ds";
    else SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Unknown finite differencing type %s",value);
  }
  ierr = PetscOptionsInt("-mat_fd_coloring_brows","Number of block rows","MatFDColoringSetBlockSize",matfd->brows,&matfd->brows,NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-mat_fd_coloring_bcols","Number of block columns","MatFDColoringSetBlockSize",matfd->bcols,&matfd->bcols,&flg);CHKERRQ(ierr);
  if (flg && matfd->bcols > matfd->ncolors) {
    /* input bcols cannot be > matfd->ncolors, thus set it as ncolors */
    matfd->bcols = matfd->ncolors;
  }

  /* process any options handlers added with PetscObjectAddOptionsHandler() */
  ierr = PetscObjectProcessOptionsHandlers((PetscObject)matfd);CHKERRQ(ierr);
  PetscOptionsEnd();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@
   RGSetFromOptions - Sets RG options from the options database.

   Collective on RG

   Input Parameters:
.  rg - the region context

   Notes:
   To see all options, run your program with the -help option.

   Level: beginner
@*/
PetscErrorCode RGSetFromOptions(RG rg)
{
  PetscErrorCode ierr;
  char           type[256];
  PetscBool      flg;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(rg,RG_CLASSID,1);
  if (!RGRegisterAllCalled) { ierr = RGRegisterAll();CHKERRQ(ierr); }
  ierr = PetscObjectOptionsBegin((PetscObject)rg);CHKERRQ(ierr);
    ierr = PetscOptionsFList("-rg_type","Region type","RGSetType",RGList,(char*)(((PetscObject)rg)->type_name?((PetscObject)rg)->type_name:RGINTERVAL),type,256,&flg);CHKERRQ(ierr);
    if (flg) {
      ierr = RGSetType(rg,type);CHKERRQ(ierr);
    }
    /*
      Set the type if it was never set.
    */
    if (!((PetscObject)rg)->type_name) {
      ierr = RGSetType(rg,RGINTERVAL);CHKERRQ(ierr);
    }

    ierr = PetscOptionsBool("-rg_complement","Whether region is complemented or not","RGSetComplement",rg->complement,&rg->complement,&flg);CHKERRQ(ierr);

    if (rg->ops->setfromoptions) {
      ierr = (*rg->ops->setfromoptions)(rg);CHKERRQ(ierr);
    }
    ierr = PetscObjectProcessOptionsHandlers((PetscObject)rg);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

PetscErrorCode MatPtAP_SeqAIJ_SeqAIJ(Mat A,Mat P,MatReuse scall,PetscReal fill,Mat *C)
{
  PetscErrorCode ierr;
  const char     *algTypes[2] = {"scalable","nonscalable"};
  PetscInt       alg=0; /* set default algorithm */

  PetscFunctionBegin;
  if (scall == MAT_INITIAL_MATRIX) {
    /* 
     Alg 'scalable' determines which implementations to be used:
       "nonscalable": do dense axpy in MatPtAPNumeric() - fastest, but requires storage of struct A*P;
       "scalable":    do two sparse axpy in MatPtAPNumeric() - might slow, does not store structure of A*P. 
     */
    ierr = PetscObjectOptionsBegin((PetscObject)A);CHKERRQ(ierr);
    ierr = PetscOptionsEList("-matptap_via","Algorithmic approach","MatPtAP",algTypes,2,algTypes[0],&alg,NULL);CHKERRQ(ierr);
    ierr = PetscOptionsEnd();CHKERRQ(ierr);
    ierr = PetscLogEventBegin(MAT_PtAPSymbolic,A,P,0,0);CHKERRQ(ierr);
    switch (alg) {
    case 1:
      ierr = MatPtAPSymbolic_SeqAIJ_SeqAIJ_DenseAxpy(A,P,fill,C);CHKERRQ(ierr);
      break;
    default:
      ierr = MatPtAPSymbolic_SeqAIJ_SeqAIJ_SparseAxpy(A,P,fill,C);CHKERRQ(ierr);
      break;
    }
    ierr = PetscLogEventEnd(MAT_PtAPSymbolic,A,P,0,0);CHKERRQ(ierr);
  }
  ierr = PetscLogEventBegin(MAT_PtAPNumeric,A,P,0,0);CHKERRQ(ierr);
  ierr = (*(*C)->ops->ptapnumeric)(A,P,*C);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(MAT_PtAPNumeric,A,P,0,0);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@
   MatColoringSetFromOptions - Sets MatColoring options from user parameters

   Collective on MatColoring

   Input Parameters:
.  mc - MatColoring context

   Options Database Keys:
+   -mat_coloring_type - the type of coloring algorithm used
.   -mat_coloring_maxcolors - the maximum number of relevant colors, all nodes not in a color are in maxcolors+1
.   -mat_coloring_distance - compute a distance 1,2,... coloring.
.   -mat_coloring_view - print information about the coloring and the produced index sets

   Level: beginner

.keywords: Coloring, Matrix

.seealso: MatColoring, MatColoringApply()
@*/
PetscErrorCode MatColoringSetFromOptions(MatColoring mc)
{
  PetscBool      flg;
  MatColoringType deft        = MATCOLORINGSL;
  char           type[256];
  PetscErrorCode ierr;
  PetscInt       dist,maxcolors;
  PetscFunctionBegin;

  PetscValidHeaderSpecific(mc,MAT_COLORING_CLASSID,1);
  ierr = MatColoringGetDistance(mc,&dist);CHKERRQ(ierr);
  ierr = MatColoringGetMaxColors(mc,&maxcolors);CHKERRQ(ierr);
  if (!MatColoringRegisterAllCalled) {ierr = MatColoringRegisterAll();CHKERRQ(ierr);}
  ierr = PetscObjectOptionsBegin((PetscObject)mc);CHKERRQ(ierr);
  if (((PetscObject)mc)->type_name) deft = ((PetscObject)mc)->type_name;
  ierr = PetscOptionsFList("-mat_coloring_type","The coloring method used","MatColoringSetType",MatColoringList,deft,type,256,&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = MatColoringSetType(mc,type);CHKERRQ(ierr);
  } else if (!((PetscObject)mc)->type_name) {
    ierr = MatColoringSetType(mc,deft);CHKERRQ(ierr);
  }
  ierr = PetscOptionsInt("-mat_coloring_distance","Distance of the coloring","MatColoringSetDistance",dist,&dist,&flg);CHKERRQ(ierr);
  if (flg) {ierr = MatColoringSetDistance(mc,dist);CHKERRQ(ierr);}
  ierr = PetscOptionsInt("-mat_coloring_maxcolors","Maximum colors returned at the end. 1 returns an independent set","MatColoringSetMaxColors",maxcolors,&maxcolors,&flg);CHKERRQ(ierr);
  if (flg) {ierr = MatColoringSetMaxColors(mc,maxcolors);CHKERRQ(ierr);}
  if (mc->ops->setfromoptions) {
    ierr = (*mc->ops->setfromoptions)(mc);CHKERRQ(ierr);
  }
  ierr = PetscOptionsBool("-mat_coloring_valid","Check that a valid coloring has been produced","",mc->valid,&mc->valid,NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnum("-mat_coloring_weight_type","Sets the type of vertex weighting used","MatColoringSetWeightType",MatColoringWeightTypes,(PetscEnum)mc->weight_type,(PetscEnum*)&mc->weight_type,NULL);CHKERRQ(ierr);
  ierr = PetscObjectProcessOptionsHandlers((PetscObject)mc);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  options->debug           = 0;
  options->dim             = 2;
  options->simplex         = PETSC_TRUE;
  options->interpolate     = PETSC_FALSE;
  options->refinementLimit = 0.0;
  options->qorder          = 0;
  options->numComponents   = 1;
  options->porder          = 0;

  ierr = PetscOptionsBegin(comm, "", "Projection Test Options", "DMPlex");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-debug", "The debugging level", "ex3.c", options->debug, &options->debug, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex3.c", options->dim, &options->dim, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-simplex", "Flag for simplices or hexhedra", "ex3.c", options->simplex, &options->simplex, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-interpolate", "Generate intermediate mesh elements", "ex3.c", options->interpolate, &options->interpolate, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-refinement_limit", "The largest allowable cell volume", "ex3.c", options->refinementLimit, &options->refinementLimit, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-qorder", "The quadrature order", "ex3.c", options->qorder, &options->qorder, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-num_comp", "The number of field components", "ex3.c", options->numComponents, &options->numComponents, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-porder", "The order of polynomials to test", "ex3.c", options->porder, &options->porder, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();

  spdim = options->dim;
  PetscFunctionReturn(0);
};

PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  options->debug          = 0;
  options->dim            = 2;
  options->cellHybrid     = PETSC_TRUE;
  options->cellSimplex    = PETSC_TRUE;
  options->testPartition  = PETSC_TRUE;
  options->testNum        = 0;
  options->simplex2tensor = PETSC_FALSE;
  options->uninterpolate  = PETSC_FALSE;
  options->reinterpolate  = PETSC_FALSE;

  ierr = PetscOptionsBegin(comm, "", "Meshing Problem Options", "DMPLEX");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-debug", "The debugging level", "ex4.c", options->debug, &options->debug, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex4.c", options->dim, &options->dim, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-cell_hybrid", "Use a hybrid mesh", "ex4.c", options->cellHybrid, &options->cellHybrid, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-cell_simplex", "Use simplices if true, otherwise hexes", "ex4.c", options->cellSimplex, &options->cellSimplex, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-test_partition", "Use a fixed partition for testing", "ex4.c", options->testPartition, &options->testPartition, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-test_num", "The particular mesh to test", "ex4.c", options->testNum, &options->testNum, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-simplex2tensor", "Refine simplicial cells in tensor product cells", "ex4.c", options->simplex2tensor, &options->simplex2tensor, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-uninterpolate", "Uninterpolate the mesh at the end", "ex4.c", options->uninterpolate, &options->uninterpolate, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-reinterpolate", "Reinterpolate the mesh at the end", "ex4.c", options->reinterpolate, &options->reinterpolate, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();
  PetscFunctionReturn(0);
}

PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  options->debug             = 0;
  options->dim               = 2;
  options->interpolate       = PETSC_FALSE;
  options->refinementLimit   = 0.0;
  options->cellSimplex       = PETSC_TRUE;
  options->filename[0]       = '\0';
  options->testPartition     = PETSC_FALSE;
  options->overlap           = PETSC_FALSE;
  options->testShape         = PETSC_FALSE;

  ierr = PetscOptionsBegin(comm, "", "Meshing Problem Options", "DMPLEX");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-debug", "The debugging level", "ex1.c", options->debug, &options->debug, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex1.c", options->dim, &options->dim, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-interpolate", "Generate intermediate mesh elements", "ex1.c", options->interpolate, &options->interpolate, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-refinement_limit", "The largest allowable cell volume", "ex1.c", options->refinementLimit, &options->refinementLimit, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-cell_simplex", "Use simplices if true, otherwise hexes", "ex1.c", options->cellSimplex, &options->cellSimplex, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsString("-filename", "The mesh file", "ex1.c", options->filename, options->filename, PETSC_MAX_PATH_LEN, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-test_partition", "Use a fixed partition for testing", "ex1.c", options->testPartition, &options->testPartition, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-overlap", "The cell overlap for partitioning", "ex1.c", options->overlap, &options->overlap, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-test_shape", "Report cell shape qualities (Jacobian condition numbers)", "ex1.c", options->testShape, &options->testShape, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();

  ierr = PetscLogEventRegister("CreateMesh",          DM_CLASSID,   &options->createMeshEvent);CHKERRQ(ierr);
  PetscFunctionReturn(0);
};

PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  PetscErrorCode ierr;

  PetscFunctionBegin;
  options->debug           = 0;
  options->dim             = 2;
  options->interpolate     = PETSC_FALSE;
  options->refinementLimit = 0.0;

  ierr = MPI_Comm_size(comm, &options->numProcs);CHKERRQ(ierr);
  ierr = MPI_Comm_rank(comm, &options->rank);CHKERRQ(ierr);
  ierr = PetscOptionsBegin(comm, "", "Mesh Distribution Options", "DMMESH");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-debug", "The debugging level", "ex1.c", options->debug, &options->debug, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex1.c", options->dim, &options->dim, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-interpolate", "Generate intermediate mesh elements", "ex1.c", options->interpolate, &options->interpolate, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsReal("-refinement_limit", "The largest allowable cell volume", "ex1.c", options->refinementLimit, &options->refinementLimit, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscStrcpy(options->filename, "");CHKERRQ(ierr);
  ierr = PetscOptionsString("-filename", "The input filename", "ex1.c", options->filename, options->filename, 2048, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscStrcpy(options->partitioner, "chaco");CHKERRQ(ierr);
  ierr = PetscOptionsString("-partitioner", "The graph partitioner", "ex1.c", options->partitioner, options->partitioner, 2048, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();

  ierr = PetscLogEventRegister("CreateMesh",    DM_CLASSID,   &options->createMeshEvent);CHKERRQ(ierr);
  PetscFunctionReturn(0);
};

static PetscErrorCode CECreate(Problem p)
{
  PetscErrorCode ierr;
  CECtx          *ce;

  PetscFunctionBeginUser;
  ierr    = PetscMalloc(sizeof(CECtx),&ce);CHKERRQ(ierr);
  p->data = (void*)ce;

  p->destroy    = &CEDestroy;
  p->function   = &CEFunction;
  p->jacobian   = &CEJacobian;
  p->solution   = &CESolution;
  p->final_time = 10;
  p->n          = 1;
  p->hasexact   = PETSC_TRUE;

  ce->lambda = 10;
  ierr       = PetscOptionsBegin(p->comm,NULL,"CE options","");CHKERRQ(ierr);
  {
    ierr = PetscOptionsReal("-problem_ce_lambda","Parameter controlling stiffness: xdot + lambda*(x - cos(t))","",ce->lambda,&ce->lambda,NULL);CHKERRQ(ierr);
  }
  ierr = PetscOptionsEnd();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

/*@C
   PetscViewerSetFromOptions - Sets the graphics type from the options database.
      Defaults to a PETSc X windows graphics.

   Collective on PetscViewer

   Input Parameter:
.     PetscViewer - the graphics context

   Level: intermediate

   Notes:
    Must be called after PetscViewerCreate() before the PetscViewer is used.

  Concepts: PetscViewer^setting options

.seealso: PetscViewerCreate(), PetscViewerSetType(), PetscViewerType

@*/
PetscErrorCode  PetscViewerSetFromOptions(PetscViewer viewer)
{
  PetscErrorCode    ierr;
  char              vtype[256];
  PetscBool         flg;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1);

  if (!PetscViewerList) {
    ierr = PetscViewerRegisterAll();CHKERRQ(ierr);
  }
  ierr = PetscObjectOptionsBegin((PetscObject)viewer);CHKERRQ(ierr);
  ierr = PetscOptionsFList("-viewer_type","Type of PetscViewer","None",PetscViewerList,(char*)(((PetscObject)viewer)->type_name ? ((PetscObject)viewer)->type_name : PETSCVIEWERASCII),vtype,256,&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscViewerSetType(viewer,vtype);CHKERRQ(ierr);
  }
  /* type has not been set? */
  if (!((PetscObject)viewer)->type_name) {
    ierr = PetscViewerSetType(viewer,PETSCVIEWERASCII);CHKERRQ(ierr);
  }
  if (viewer->ops->setfromoptions) {
    ierr = (*viewer->ops->setfromoptions)(PetscOptionsObject,viewer);CHKERRQ(ierr);
  }

  /* process any options handlers added with PetscObjectAddOptionsHandler() */
  ierr = PetscObjectProcessOptionsHandlers((PetscObject)viewer);CHKERRQ(ierr);
  ierr = PetscViewerViewFromOptions(viewer,NULL,"-viewer_view");CHKERRQ(ierr);
  ierr = PetscOptionsEnd();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *options)
{
  const char    *names[8] = {"none", "ghosted", "mirror", "periodic", "twist", "DMBoundaryType", "DM_BOUNDARY_", NULL};
  PetscInt       n;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  options->dim            = 2;
  options->cellSimplex    = PETSC_TRUE;
  options->faces[0]       = 1;
  options->faces[1]       = 1;
  options->faces[2]       = 1;
  options->periodicity[0] = DM_BOUNDARY_NONE;
  options->periodicity[1] = DM_BOUNDARY_NONE;
  options->periodicity[2] = DM_BOUNDARY_NONE;
  options->filename[0]    = '\0';

  ierr = PetscOptionsBegin(comm, "", "Meshing Interpolation Test Options", "DMPLEX");CHKERRQ(ierr);
  ierr = PetscOptionsInt("-dim", "The topological mesh dimension", "ex32.c", options->dim, &options->dim, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsBool("-cell_simplex", "Use simplices if true, otherwise hexes", "ex32.c", options->cellSimplex, &options->cellSimplex, NULL);CHKERRQ(ierr);
  n    = 3;
  ierr = PetscOptionsIntArray("-faces", "Faces per direction", "ex32.c", options->faces, &n, NULL);CHKERRQ(ierr);
  n    = 3;
  ierr = PetscOptionsEnumArray("-periodicity", "Periodicity per direction", "ex32.c", names, (PetscEnum *) options->periodicity, &n, &options->isPeriodic);CHKERRQ(ierr);
  ierr = PetscOptionsString("-filename", "The mesh file", "ex32.c", options->filename, options->filename, PETSC_MAX_PATH_LEN, NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd();
  PetscFunctionReturn(0);
}

/*@
   MatPartitioningSetFromOptions - Sets various partitioning options from the
        options database.

   Collective on MatPartitioning

   Input Parameter:
.  part - the partitioning context.

   Options Database Command:
$  -mat_partitioning_type  <type>
$      Use -help for a list of available methods
$      (for instance, parmetis)

   Level: beginner

.keywords: partitioning, set, method, type
@*/
PetscErrorCode  MatPartitioningSetFromOptions(MatPartitioning part)
{
  PetscErrorCode ierr;
  PetscBool      flag;
  char           type[256];
  const char     *def;

  PetscFunctionBegin;
  ierr = PetscObjectOptionsBegin((PetscObject)part);CHKERRQ(ierr);
  if (!((PetscObject)part)->type_name) {
#if defined(PETSC_HAVE_PARMETIS)
    def = MATPARTITIONINGPARMETIS;
#else
    def = MATPARTITIONINGCURRENT;
#endif
  } else {
    def = ((PetscObject)part)->type_name;
  }
  ierr = PetscOptionsList("-mat_partitioning_type","Type of partitioner","MatPartitioningSetType",MatPartitioningList,def,type,256,&flag);CHKERRQ(ierr);
  if (flag) {
    ierr = MatPartitioningSetType(part,type);CHKERRQ(ierr);
  }
  /*
    Set the type if it was never set.
  */
  if (!((PetscObject)part)->type_name) {
    ierr = MatPartitioningSetType(part,def);CHKERRQ(ierr);
  }

  if (part->ops->setfromoptions) {
    ierr = (*part->ops->setfromoptions)(part);CHKERRQ(ierr);
  }
  ierr = PetscOptionsEnd();CHKERRQ(ierr);
  PetscFunctionReturn(0);
}