#include <deal.II/lac/petsc_solver.h>

Inheritance diagram for PETScWrappers::SparseDirectMUMPS:

Classes
struct	AdditionalData

struct	SolverDataMUMPS

Public Member Functions
	SparseDirectMUMPS (SolverControl &cn, const MPI_Comm &mpi_communicator=PETSC_COMM_SELF, const AdditionalData &data=AdditionalData())

void	solve (const MatrixBase &A, VectorBase &x, const VectorBase &b)

void	set_symmetric_mode (const bool flag)

Public Member Functions inherited from PETScWrappers::SolverBase
	SolverBase (SolverControl &cn, const MPI_Comm &mpi_communicator)

virtual	~SolverBase ()=default

void	solve (const MatrixBase &A, VectorBase &x, const VectorBase &b, const PreconditionerBase &preconditioner)

virtual void	reset ()

void	set_prefix (const std::string &prefix)

SolverControl &	control () const

void	initialize (const PreconditionerBase &preconditioner)

Protected Member Functions
virtual void	set_solver_type (KSP &ksp) const override

Protected Attributes
const AdditionalData	additional_data

Protected Attributes inherited from PETScWrappers::SolverBase
SolverControl &	solver_control

const MPI_Comm	mpi_communicator

std::string	prefix_name

Static Private Member Functions
static PetscErrorCode	convergence_test (KSP ksp, const PetscInt iteration, const PetscReal residual_norm, KSPConvergedReason reason, void solver_control)

Private Attributes
bool	symmetric_mode

Detailed Description

An implementation of the solver interface using the sparse direct MUMPS solver through PETSc. This class has the usual interface of all other solver classes but it is of course different in that it doesn't implement an iterative solver. As a consequence, things like the SolverControl object have no particular meaning here.

MUMPS allows to make use of symmetry in this matrix. In this class this is made possible by the set_symmetric_mode() function. If your matrix is symmetric, you can use this class as follows:

SolverControl cn;
PETScWrappers::SparseDirectMUMPS solver(cn, mpi_communicator);
solver.set_symmetric_mode(true);
solver.solve(system_matrix, solution, system_rhs);

Note: The class internally calls KSPSetFromOptions thus you are able to use all the PETSc parameters for MATSOLVERMUMPS package. See http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MATSOLVERMUMPS.html

Author: Daniel Brauss, Alexander Grayver, 2012

Definition at line 934 of file petsc_solver.h.

Constructor & Destructor Documentation

◆ SparseDirectMUMPS()

PETScWrappers::SparseDirectMUMPS::SparseDirectMUMPS	(	SolverControl &	cn,
		const MPI_Comm &	mpi_communicator = `PETSC_COMM_SELF`,
		const AdditionalData &	data = `AdditionalData()`
	)

Constructor

Definition at line 634 of file petsc_solver.cc.

Member Function Documentation

◆ solve()

void PETScWrappers::SparseDirectMUMPS::solve	(	const MatrixBase &	A,
		VectorBase &	x,
		const VectorBase &	b
	)

The method to solve the linear system.

factorization matrix to be obtained from MUMPS

setting MUMPS integer control parameters ICNTL to be passed to MUMPS. Setting entry 7 of MUMPS ICNTL array (of size 40) to a value of 2. This sets use of Approximate Minimum Fill (AMF)

number of iterations to solution (should be 1) for a direct solver

norm of residual

creating a solver object if this is necessary

creates the default KSP context and puts it in the location solver_data->ksp

set the matrices involved. the last argument is irrelevant here, since we use the solver only once anyway

setting the solver type

getting the associated preconditioner context

build PETSc PC for particular PCLU or PCCHOLESKY preconditioner depending on whether the symmetric mode has been set

convergence monitor function that checks with the solver_control object for convergence

set the software that is to be used to perform the lu factorization here we start to see differences with the base class solve function

set up the package to call for the factorization

get the factored matrix F from the preconditioner context. This routine is valid only for LU, ILU, Cholesky, and incomplete Cholesky

Passing the control parameters to MUMPS

set the command line option prefix name

set the command line options provided by the user to override the defaults

solve the linear system

in case of failure throw exception

obtain convergence information. obtain the number of iterations and residual norm

Definition at line 671 of file petsc_solver.cc.

◆ set_symmetric_mode()

void PETScWrappers::SparseDirectMUMPS::set_symmetric_mode ( const bool flag )

The method allows to take advantage if the system matrix is symmetric by using LDL^T decomposition instead of more expensive LU. The argument indicates whether the matrix is symmetric or not.

Definition at line 884 of file petsc_solver.cc.

◆ set_solver_type()

void PETScWrappers::SparseDirectMUMPS::set_solver_type ( KSP & ksp ) const

overrideprotectedvirtual

Function that takes a Krylov Subspace Solver context object, and sets the type of solver that is requested by the derived class.

KSPPREONLY implements a stub method that applies only the preconditioner. Its use is due to SparseDirectMUMPS being a direct (rather than iterative) solver

The KSPPREONLY solver of PETSc never calls the convergence monitor, which leads to failure even when everything was ok. Therefore, the SolverControl status is set to some nice values, which guarantee a nice result at the end of the solution process.

Using a PREONLY solver with a nonzero initial guess leads PETSc to produce some error messages.

Implements PETScWrappers::SolverBase.

Definition at line 644 of file petsc_solver.cc.

◆ convergence_test()

PetscErrorCode PETScWrappers::SparseDirectMUMPS::convergence_test	(	KSP	ksp,
		const PetscInt	iteration,
		const PetscReal	residual_norm,
		KSPConvergedReason *	reason,
		void *	solver_control
	)

staticprivate

A function that is used in PETSc as a callback to check convergence. It takes the information provided from PETSc and checks it against deal.II's own SolverControl objects to see if convergence has been reached.

Definition at line 847 of file petsc_solver.cc.

Member Data Documentation

◆ additional_data

const AdditionalData PETScWrappers::SparseDirectMUMPS::additional_data

protected

Store a copy of flags for this particular solver.

Definition at line 967 of file petsc_solver.h.

◆ symmetric_mode

bool PETScWrappers::SparseDirectMUMPS::symmetric_mode

private

Flag specifies whether matrix being factorized is symmetric or not. It influences the type of the used preconditioner (PCLU or PCCHOLESKY)

Definition at line 1008 of file petsc_solver.h.

The documentation for this class was generated from the following files:

deal.II/lac/petsc_solver.h
source/lac/petsc_solver.cc

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Static Private Member Functions

Private Attributes