Set data structures of MG pre-conditioner via approximation orders. More...

#include <users_modules/basic_finite_elements/src/PCMGSetUpViaApproxOrders.hpp>

Collaboration diagram for PCMGSetUpViaApproxOrdersCtx:

Public Member Functions
	PCMGSetUpViaApproxOrdersCtx (DM dm, Mat a, bool shell_sub_a)

virtual	~PCMGSetUpViaApproxOrdersCtx ()=default

virtual MoFEMErrorCode	getOptions ()
	get options from line command More...

virtual MoFEMErrorCode	createIsAtLevel (int kk, IS *is)
	Set IS for levels. More...

virtual MoFEMErrorCode	destroyIsAtLevel (int kk, IS *is)
	Destroy IS if internally created. More...

virtual MoFEMErrorCode	buildProlongationOperator (bool use_mat_a, int verb=0)
	Set up data structures for MG. More...

Public Attributes
DM	dM
	Distributed mesh manager. More...

Mat	A
	Matrix at fine level. More...

int	nbLevels
	number of multi-grid levels More...

int	coarseOrder
	approximation order of coarse level More...

int	orderAtLastLevel
	set maximal evaluated order More...

bool	shellSubA

int	verboseLevel

Detailed Description

Set data structures of MG pre-conditioner via approximation orders.

Examples: elasticity.cpp.

Definition at line 190 of file PCMGSetUpViaApproxOrders.hpp.

Constructor & Destructor Documentation

◆ PCMGSetUpViaApproxOrdersCtx()

PCMGSetUpViaApproxOrdersCtx::PCMGSetUpViaApproxOrdersCtx	(	DM	dm,
		Mat	a,
		bool	shell_sub_a
	)

inline

Definition at line 198 of file PCMGSetUpViaApproxOrders.hpp.

199 : dM(dm), A(a), nbLevels(2), coarseOrder(2), orderAtLastLevel(1000),

200 shellSubA(shell_sub_a), verboseLevel(0) {}

◆ ~PCMGSetUpViaApproxOrdersCtx()

virtual PCMGSetUpViaApproxOrdersCtx::~PCMGSetUpViaApproxOrdersCtx ( )

virtualdefault

Member Function Documentation

◆ buildProlongationOperator()

MoFEMErrorCode PCMGSetUpViaApproxOrdersCtx::buildProlongationOperator	(	bool	use_mat_a,
		int	verb = `0`
	)

virtual

Set up data structures for MG.

Parameters

pc	MG pre-conditioner http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCMG.html
verb	verbosity level

Returns: error code

Definition at line 660 of file PCMGSetUpViaApproxOrders.cpp.

                                                                  {
   MoFEMFunctionBegin;
   verb = verb > verboseLevel ? verb : verboseLevel;
  
   MPI_Comm comm;
   CHKERR PetscObjectGetComm((PetscObject)dM, &comm);
  
   if (verb > QUIET) {
     PetscPrintf(comm, "set MG levels %u\n", nbLevels);
   }
  
   std::vector<IS> is_vec(nbLevels + 1);
   std::vector<int> is_glob_size(nbLevels + 1), is_loc_size(nbLevels + 1);
  
   for (int kk = 0; kk < nbLevels; kk++) {
  
     // get indices up to up to give approximation order
     CHKERR createIsAtLevel(kk, &is_vec[kk]);
     CHKERR ISGetSize(is_vec[kk], &is_glob_size[kk]);
     CHKERR ISGetLocalSize(is_vec[kk], &is_loc_size[kk]);
  
     if (verb > QUIET) {
       PetscSynchronizedPrintf(comm,
                               "Nb. dofs at level [ %d ] global %u local %d\n",
                               kk, is_glob_size[kk], is_loc_size[kk]);
     }
  
     // if no dofs on level kk finish here
     if (is_glob_size[kk] == 0) {
       SETERRQ(PETSC_COMM_SELF, MOFEM_DATA_INCONSISTENCY, "no dofs at level");
     }
   }
  
   for (int kk = 0; kk != nbLevels; kk++) {
     Mat subA;
     if (kk == nbLevels - 1 && use_mat_a) {
       subA = A;
       CHKERR DMMGViaApproxOrdersPushBackCoarseningIS(dM, is_vec[kk], A, &subA,
                                                      false, false);
     } else {
       if (kk > 0) {
         // Not coarse level
         CHKERR DMMGViaApproxOrdersPushBackCoarseningIS(dM, is_vec[kk], A, &subA,
                                                        true, shellSubA);
       } else {
         // Coarse lave is compressed matrix allowing for factorization when
         // needed
         CHKERR DMMGViaApproxOrdersPushBackCoarseningIS(dM, is_vec[kk], A, &subA,
                                                        true, false);
       }
       if (subA) {
         CHKERR MatDestroy(&subA);
       }
     }
   }
  
   for (unsigned int kk = 0; kk < is_vec.size(); kk++) {
     CHKERR destroyIsAtLevel(kk, &is_vec[kk]);
   }
  
   if (verb > QUIET) {
     PetscSynchronizedFlush(comm, PETSC_STDOUT);
   }
  
   MoFEMFunctionReturn(0);
 }

◆ createIsAtLevel()

MoFEMErrorCode PCMGSetUpViaApproxOrdersCtx::createIsAtLevel	(	int	kk,
		IS *	is
	)

virtual

Set IS for levels.

Parameters

kk	level
is	pointer to IS

Returns: error code

Definition at line 626 of file PCMGSetUpViaApproxOrders.cpp.

                                                                           {
   MoFEM::Interface *m_field_ptr;
   MoFEM::ISManager *is_manager_ptr;
   MoFEMFunctionBegin;
   // if is last level, take all remaining orders dofs, if any left
   CHKERR DMoFEMGetInterfacePtr(dM, &m_field_ptr);
   CHKERR m_field_ptr->getInterface(is_manager_ptr);
   const Problem *problem_ptr;
   CHKERR DMMoFEMGetProblemPtr(dM, &problem_ptr);
   int order_at_next_level = kk + coarseOrder;
   if (kk == nbLevels - 1) {
     int first = problem_ptr->getNumeredRowDofsPtr()
                     ->get<PetscLocalIdx_mi_tag>()
                     .find(0)
                     ->get()
                     ->getPetscGlobalDofIdx();
     CHKERR ISCreateStride(PETSC_COMM_WORLD, problem_ptr->getNbLocalDofsRow(),
                           first, 1, is);
     MoFEMFunctionReturnHot(0);
     // order_at_next_level = orderAtLastLevel;
   }
   string problem_name = problem_ptr->getName();
   CHKERR is_manager_ptr->isCreateProblemOrder(problem_name, ROW, 0,
                                               order_at_next_level, is);
   MoFEMFunctionReturn(0);
 }

◆ destroyIsAtLevel()

MoFEMErrorCode PCMGSetUpViaApproxOrdersCtx::destroyIsAtLevel	(	int	kk,
		IS *	is
	)

virtual

Destroy IS if internally created.

Parameters

kk	level
is	pointer to is

Returns: error code

Definition at line 653 of file PCMGSetUpViaApproxOrders.cpp.

                                                                            {
   MoFEMFunctionBegin;
   CHKERR ISDestroy(is);
   MoFEMFunctionReturn(0);
 }

◆ getOptions()

MoFEMErrorCode PCMGSetUpViaApproxOrdersCtx::getOptions ( )

virtual

get options from line command

Returns: error code

Definition at line 601 of file PCMGSetUpViaApproxOrders.cpp.

                                                        {
   MoFEMFunctionBeginHot;
   ierr = PetscOptionsBegin(PETSC_COMM_WORLD, "",
                            "MOFEM Multi-Grid (Orders) pre-conditioner", "none");
   CHKERRG(ierr);
  
   CHKERR PetscOptionsInt("-mofem_mg_levels", "nb levels of multi-grid solver",
                          "", 2, &nbLevels, PETSC_NULL);
   CHKERR PetscOptionsInt("-mofem_mg_coarse_order",
                          "approximation order of coarse level", "", 2,
                          &coarseOrder, PETSC_NULL);
   CHKERR PetscOptionsInt("-mofem_mg_order_at_last_level", "order at last level",
                          "", 100, &orderAtLastLevel, PETSC_NULL);
   CHKERR PetscOptionsInt("-mofem_mg_verbose", "nb levels of multi-grid solver",
                          "", 0, &verboseLevel, PETSC_NULL);
   PetscBool shell_sub_a = shellSubA ? PETSC_TRUE : PETSC_FALSE;
   CHKERR PetscOptionsBool("-mofem_mg_shell_a", "use shell matrix as sub matrix",
                           "", shell_sub_a, &shell_sub_a, NULL);
   shellSubA = (shellSubA == PETSC_TRUE);
  
   ierr = PetscOptionsEnd();
   CHKERRG(ierr);
   MoFEMFunctionReturnHot(0);
 }