PreconditionRichardson Class Reference

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

Inheritance diagram for PreconditionRichardson:

Classes
class	AdditionalData

Public Types
typedef types::global_dof_index	size_type

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 &)
virtual	~Subscriptor ()
Subscriptor &	operator= (const Subscriptor &)
void	subscribe (const char *identifier=0) const
void	unsubscribe (const char *identifier=0) const
unsigned int	n_subscriptions () const
void	list_subscribers () const
	DeclException3 (ExcInUse, int, char *, std::string &,<< "Object of class "<< arg2<< " is still used by "<< arg1<< " other objects."<< "\"<< "(Additional information: "<< arg3<< ")\"<< "See the entry in the Frequently Asked Questions of "<< "deal.II (linked to from http://www.dealii.org/) for "<< "a lot more information on what this error means and "<< "how to fix programs in which it happens.")
	DeclException2 (ExcNoSubscriber, char *, char *,<< "No subscriber with identifier <"<< arg2<< "> subscribes to this object of class "<< arg1<< ". Consequently, it cannot be unsubscribed.")
template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Private Attributes
double	relaxation
size_type	n_rows
size_type	n_columns

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 182 of file precondition.h.

Member Typedef Documentation

size_type

typedef types::global_dof_index PreconditionRichardson::size_type

Declare type for container size.

Definition at line 188 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 257 of file precondition.h.

m()

size_type PreconditionRichardson::m

(

)

const

Return the dimension of the codomain (or range) space. To remember: the matrix is of dimension .

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. To remember: the matrix is of dimension .

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 281 of file precondition.h.

n_rows

size_type PreconditionRichardson::n_rows

private

The dimension of the range space.

Definition at line 286 of file precondition.h.

n_columns

size_type PreconditionRichardson::n_columns

private

The dimension of the domain space.

Definition at line 291 of file precondition.h.

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

• deal.II/lac/precondition.h