Stagnation stopping criterion. More...

#include <ResidualStagnation.hpp>

Inheritance diagram for lama::ResidualStagnation:

Public Types
enum	BooleanOperator { AND, OR }
	Defines the operators which can be used to connect Criterions with. More...
Public Member Functions
	ResidualStagnation (NormPtr norm)
	Creates a new Stagnation based stopping criterion.
	ResidualStagnation (NormPtr norm, IndexType lookback, Scalar precision)
	Creates a new Stagnation based stopping criterion.
	ResidualStagnation (const ResidualStagnation &other)
virtual	~ResidualStagnation ()
virtual Criterion *	copy () const
virtual bool	isSatisfied (const IterativeSolver &solver)
	Checks if the criterion is satisfied.
IndexType	getLookback () const
	Gets the amount of calculations used for the criterion check.
const NormPtr	getNorm () const
	Gets the Norm which the criterion uses for the check.
const Scalar	getPrecision () const
	Returns the precision for floating point number calculations related to the Norm.
void	setLookback (const IndexType lookback)
	Sets the amount of calculations used for the criterion check.
void	setPrecision (const Scalar precision)
	Sets the precision for floating point number calculations related to the Norm.
virtual void	writeAt (std::ostream &stream) const
	Writes some Information about this to the passed stream.
const CriterionPtr	getLeftChild () const
const CriterionPtr	getRightChild () const
BooleanOperator	getOperation () const
void	setLeftChild (const CriterionPtr leftChild)
void	setRightChild (const CriterionPtr rightChild)
void	setOperation (const BooleanOperator operation)
bool	hasLeftChild () const
	Returns true if the boolean condition has a left child Do not use getLeftChild() to compare pointers.
bool	hasRightChild () const
	Returns true if the boolean condition has a right child Do not use getRightChild() to compare pointers.
Protected Member Functions
	LAMA_LOG_DECL_STATIC_LOGGER (logger)
Private Attributes
const NormPtr	mNorm
	The norm used in the residual-norm-calculation.
IndexType	mLookback
	The amount of calculations used for the criterion check.
std::vector< Scalar >	mLastResidualNorms
	Stores the results of the residual-norm-calculations.
IndexType	mNextEntry
	Index.
bool	mEntriesReady
	Used to check, if enough data have been gathered to check the criterion.
Scalar	mPrecision
	The precision used for the stagnation check.

Detailed Description

Stagnation stopping criterion.

Parameters:

IterativeSolver The type solver in which this criterion is used. Most commonly this is the abstract sblas::IterativeSolver type.

Member Enumeration Documentation

enum lama::Criterion::BooleanOperator [inherited]

Defines the operators which can be used to connect Criterions with.

Enumerator:

AND	stands for logical and composition
OR	stands for logical or composition

Constructor & Destructor Documentation

lama::ResidualStagnation::ResidualStagnation ( NormPtr norm )

Creates a new Stagnation based stopping criterion.

Parameters:

norm	The norm which shall be used to check the criterion. Has to be compatible with the Matrix/Vector types of the solver.

Referenced by copy().

lama::ResidualStagnation::ResidualStagnation	(	NormPtr	norm,
		IndexType	lookback,
		Scalar	precision
	)

Creates a new Stagnation based stopping criterion.

Parameters:

norm	The norm which shall be used to check the criterion. Has to be compatible with the Matrix/Vector types of the solver.
lookback	The amount of residual-norm-calculation results used for the criterion check.

lama::ResidualStagnation::ResidualStagnation ( const ResidualStagnation & other )

lama::ResidualStagnation::~ResidualStagnation ( ) [virtual]

Member Function Documentation

Criterion * lama::ResidualStagnation::copy ( ) const [virtual]

References ResidualStagnation().

const CriterionPtr lama::Criterion::getLeftChild ( ) const [inherited]

References lama::Criterion::mLeftChild.

Referenced by lama::Criterion::writeAt().

int lama::ResidualStagnation::getLookback ( ) const

Gets the amount of calculations used for the criterion check.

return Amount of calculations.

References mLookback.

Referenced by writeAt().

const NormPtr lama::ResidualStagnation::getNorm ( ) const

Gets the Norm which the criterion uses for the check.

Returns:: The Norm used.

References mNorm.

Criterion::BooleanOperator lama::Criterion::getOperation ( ) const [inherited]

References lama::Criterion::mOperation.

Referenced by lama::Criterion::writeAt().

const Scalar lama::ResidualStagnation::getPrecision ( ) const

Returns the precision for floating point number calculations related to the Norm.

Returns:: mPrecision The precision given in a Scalar object.

References mPrecision.

Referenced by writeAt().

const CriterionPtr lama::Criterion::getRightChild ( ) const [inherited]

References lama::Criterion::mRightChild.

Referenced by lama::Criterion::writeAt().

bool lama::Criterion::hasLeftChild ( ) const [inherited]

Returns true if the boolean condition has a left child Do not use getLeftChild() to compare pointers.

Logical operations are overwritten

return Returns true if the boolean condition has a left child. If pointer is not set: false

References lama::Criterion::mLeftChild.

Referenced by lama::Criterion::isSatisfied(), and lama::Criterion::writeAt().

bool lama::Criterion::hasRightChild ( ) const [inherited]

Returns true if the boolean condition has a right child Do not use getRightChild() to compare pointers.

Logical operations are overwritten

return Returns true if the boolean condition has a right child. If pointer is not set: false

References lama::Criterion::mRightChild.

Referenced by lama::Criterion::isSatisfied(), and lama::Criterion::writeAt().

bool lama::ResidualStagnation::isSatisfied ( const IterativeSolver & solver ) [virtual]

Checks if the criterion is satisfied.

The Stagnation criterion needs a certain amount (specified by m_lookback) to be able to perform the check. If this method is called and not enough data has been gathered, false is returned. Anyhow the norm of the residual is calculated and stored. This process continues, until enough data has been gathered.

Parameters:

solver The solver which calls this method. Needed for residual computation.