PETScWrappers::SparseDirectMUMPS Class Reference

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

Inheritance diagram for PETScWrappers::SparseDirectMUMPS:

Classes
struct	AdditionalData

Public Member Functions
	SparseDirectMUMPS (SolverControl &cn, const AdditionalData &data=AdditionalData())
	SparseDirectMUMPS (SolverControl &cn, const MPI_Comm mpi_communicator, const AdditionalData &data=AdditionalData())
void	solve (const MatrixBase &A, VectorBase &x, const VectorBase &b)
void	set_symmetric_mode (const bool matrix_is_symmetric)
void	solve (const MatrixBase &A, VectorBase &x, const VectorBase &b, const PreconditionBase &preconditioner)
virtual void	reset ()
void	set_prefix (const std::string &prefix)
SolverControl &	control () const
void	initialize (const PreconditionBase &preconditioner)
KSP	petsc_ksp ()
	operator KSP () const

Protected Member Functions
virtual void	set_solver_type (KSP &ksp) const override
void	initialize_ksp_with_comm (const MPI_Comm comm)
void	perhaps_set_convergence_test () const

Protected Attributes
const AdditionalData	additional_data
bool	symmetric_mode
KSP	ksp
SmartPointer< SolverControl, SolverBase >	solver_control
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)

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

Definition at line 903 of file petsc_solver.h.

Constructor & Destructor Documentation

SparseDirectMUMPS() [1/2]

PETScWrappers::SparseDirectMUMPS::SparseDirectMUMPS	(	SolverControl &	cn,
		const AdditionalData &	data = AdditionalData() )

Constructor.

Definition at line 641 of file petsc_solver.cc.

SparseDirectMUMPS() [2/2]

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

Constructor. This constructor is deprecated and ignores the MPI communicator argument. Use the other constructor instead.

Deprecated

Definition at line 650 of file petsc_solver.cc.

Member Function Documentation

solve() [1/2]

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

The method to solve the linear system.

Definition at line 684 of file petsc_solver.cc.

set_symmetric_mode()

void PETScWrappers::SparseDirectMUMPS::set_symmetric_mode

(

const bool

matrix_is_symmetric

)

If called with true as argument, tell the direct solver to assume that the system matrix is symmetric. It does so by computing the LDL^T decomposition (in effect, a Cholesky decomposition) instead of more expensive LU decomposition. The argument indicates whether the matrix can be assumed to be symmetric or not.

Note that most finite element matrices are "structurally symmetric", i.e., the sparsity pattern is symmetric, even though the matrix is not. An example of a matrix that is structurally symmetric but not symmetric is the matrix you obtain by discretizing the advection equation \(\nabla \cdot (\vec\beta u) = f\) (see, for example step-12). Because the operator here is not symmetric, the matrix is not symmetric either; however, if matrix entry \(A_{ij}\) is nonzero, then matrix entry \(A_{ji}\) is generally not zero either (and in any case, DoFTools::make_sparsity_pattern() will create a symmetric sparsity pattern). That said, the current function is not meant to indicate whether the sparsity pattern is symmetric, but whether the matrix itself is symmetric, and this typically requires that the differential operator you are considering is symmetric.

Definition at line 814 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.

Reimplemented from PETScWrappers::SolverBase.

Definition at line 659 of file petsc_solver.cc.

solve() [2/2]

void SolverBase< VectorType >::solve ( const MatrixBase & A, VectorBase & x, const VectorBase & b, const PreconditionBase & preconditioner )

inherited

Solve the linear system Ax=b. Depending on the information provided by derived classes and the object passed as a preconditioner, one of the linear solvers and preconditioners of PETSc is chosen. Repeated calls to solve() do not reconstruct the preconditioner for performance reasons. See class Documentation.

Definition at line 83 of file petsc_solver.cc.

reset()

void SolverBase< VectorType >::reset ( )

virtualinherited

Resets the contained preconditioner and solver object. See class description for more details.

Definition at line 148 of file petsc_solver.cc.

set_prefix()

void SolverBase< VectorType >::set_prefix ( const std::string & prefix )

inherited

Sets a prefix name for the solver object. Useful when customizing the PETSc KSP object with command-line options.

Definition at line 141 of file petsc_solver.cc.

control()

SolverControl & SolverBase< VectorType >::control ( ) const

inherited

Access to object that controls convergence.

Definition at line 155 of file petsc_solver.cc.

initialize()

void SolverBase< VectorType >::initialize ( const PreconditionBase & preconditioner )

inherited

initialize the solver with the preconditioner. This function is intended for use with SLEPc spectral transformation class.

Definition at line 231 of file petsc_solver.cc.

petsc_ksp()

KSP SolverBase< VectorType >::petsc_ksp ( )

inherited

Return the PETSc KSP object.

Definition at line 68 of file petsc_solver.cc.

operator KSP()

SolverBase< VectorType >::operator KSP ( ) const

inherited

Conversion operator to gain access to the underlying PETSc type. If you do this, you cut this class off some information it may need, so this conversion operator should only be used if you know what you do.

Definition at line 75 of file petsc_solver.cc.

initialize_ksp_with_comm()

void SolverBase< VectorType >::initialize_ksp_with_comm ( const MPI_Comm comm )

protectedinherited

Utility to create the KSP object and attach convergence test.

Definition at line 206 of file petsc_solver.cc.

perhaps_set_convergence_test()

void SolverBase< VectorType >::perhaps_set_convergence_test ( ) const

protectedinherited

Utility to use deal.II convergence testing.

This call changes the convergence criterion when the instance of the class has a SolverControl object associated.

Definition at line 222 of file petsc_solver.cc.

convergence_test()

PetscErrorCode SolverBase< VectorType >::convergence_test ( KSP ksp, const PetscInt iteration, const PetscReal residual_norm, KSPConvergedReason * reason, void * solver_control )

staticprivateinherited

A function that is used in PETSc as a callback to check on 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 166 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 965 of file petsc_solver.h.

symmetric_mode

bool PETScWrappers::SparseDirectMUMPS::symmetric_mode

protected

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

Definition at line 974 of file petsc_solver.h.

ksp

KSP PETScWrappers::SolverBase::ksp

protectedinherited

The PETSc KSP object.

Definition at line 167 of file petsc_solver.h.

solver_control

SmartPointer<SolverControl, SolverBase> PETScWrappers::SolverBase::solver_control

protectedinherited

Reference to the object that controls convergence of the iterative solver. In fact, for these PETSc wrappers, PETSc does so itself, but we copy the data from this object before starting the solution process, and copy the data back into it afterwards.

Definition at line 175 of file petsc_solver.h.

prefix_name

std::string PETScWrappers::SolverBase::prefix_name

protectedinherited

Solver prefix name to qualify options specific to the PETSc KSP object in the current context. Note: A hyphen (-) must NOT be given at the beginning of the prefix name. The first character of all runtime options is AUTOMATICALLY the hyphen.

Definition at line 205 of file petsc_solver.h.

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

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