PreconditionRichardson Class Reference

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

Inheritance diagram for PreconditionRichardson:

Classes
class	AdditionalData

Public Types
using	size_type = types::global_dof_index

Public Member Functions
	PreconditionRichardson ()
void	initialize (const AdditionalData &parameters)
template<typename MatrixType >
void	initialize (const MatrixType &matrix, const AdditionalData &parameters)
template<class VectorType >
void	vmult (VectorType &, const VectorType &) const
template<class VectorType >
void	Tvmult (VectorType &, const VectorType &) const
template<class VectorType >
void	vmult_add (VectorType &, const VectorType &) const
template<class VectorType >
void	Tvmult_add (VectorType &, const VectorType &) const
void	clear ()
size_type	m () const
size_type	n () const
Public Member Functions inherited from Subscriptor
	Subscriptor ()
	Subscriptor (const Subscriptor &)
	Subscriptor (Subscriptor &&) noexcept
virtual	~Subscriptor ()
Subscriptor &	operator= (const Subscriptor &)
Subscriptor &	operator= (Subscriptor &&) noexcept
void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const
unsigned int	n_subscriptions () const
template<typename StreamType >
void	list_subscribers (StreamType &stream) const
void	list_subscribers () const
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Private Attributes
double	relaxation
size_type	n_rows
size_type	n_columns

Additional Inherited Members
Static Public Member Functions inherited from Subscriptor
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)
static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Detailed Description

Preconditioning with Richardson's method. This preconditioner just scales the vector with a constant relaxation factor provided by the AdditionalData object.

In Krylov-space methods, this preconditioner should not have any effect. Using SolverRichardson, the two relaxation parameters will be just multiplied. Still, this class is useful in multigrid smoother objects (MGSmootherRelaxation).

Author

Guido Kanschat, 2005; extension for full compatibility with LinearOperator class: Jean-Paul Pelteret, 2015

Definition at line 197 of file precondition.h.

Member Typedef Documentation

size_type

using PreconditionRichardson::size_type = types::global_dof_index

Declare type for container size.

Definition at line 203 of file precondition.h.

Constructor & Destructor Documentation

PreconditionRichardson()

PreconditionRichardson::PreconditionRichardson

(

)

Constructor, sets the relaxation parameter, domain and range sizes to their default.

Member Function Documentation

initialize() [1/2]

void PreconditionRichardson::initialize

(

const AdditionalData &

parameters

)

Change the relaxation parameter.

initialize() [2/2]

template<typename MatrixType >

void PreconditionRichardson::initialize	(	const MatrixType &	matrix,
		const AdditionalData &	parameters
	)

Change the relaxation parameter in a way consistent with other preconditioners. The matrix argument is ignored and here just for compatibility with more complex preconditioners.

vmult()

template<class VectorType >

void PreconditionRichardson::vmult	(	VectorType &	,
		const VectorType &
	)		const

Apply preconditioner.

Tvmult()

template<class VectorType >

void PreconditionRichardson::Tvmult	(	VectorType &	,
		const VectorType &
	)		const

Apply transpose preconditioner. Since this is the identity, this function is the same as vmult().

vmult_add()

template<class VectorType >

void PreconditionRichardson::vmult_add	(	VectorType &	,
		const VectorType &
	)		const

Apply preconditioner, adding to the previous value.

Tvmult_add()

template<class VectorType >

void PreconditionRichardson::Tvmult_add	(	VectorType &	,
		const VectorType &
	)		const

Apply transpose preconditioner, adding. Since this is the identity, this function is the same as vmult_add().

clear()

void PreconditionRichardson::clear ( )

inline

This function is only present to provide the interface of a preconditioner to be handed to a smoother. This does nothing.

Definition at line 278 of file precondition.h.

m()

size_type PreconditionRichardson::m

(

)

const

Return the dimension of the codomain (or range) space. Note that the matrix is of dimension \(m \times n\).

Note

This function should only be called if the preconditioner has been initialized.

n()

size_type PreconditionRichardson::n

(

)

const

Return the dimension of the domain space. Note that the matrix is of dimension \(m \times n\).

Note

This function should only be called if the preconditioner has been initialized.

Member Data Documentation

relaxation

double PreconditionRichardson::relaxation

private

The relaxation parameter multiplied with the vectors.

Definition at line 305 of file precondition.h.

n_rows

size_type PreconditionRichardson::n_rows

private

The dimension of the range space.

Definition at line 310 of file precondition.h.

n_columns

size_type PreconditionRichardson::n_columns

private

The dimension of the domain space.

Definition at line 315 of file precondition.h.

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

• deal.II/lac/precondition.h