A class for preconditioning with Chebyshev polynomials. More...

#include <Ifpack2_Chebyshev_decl.hpp>

Inheritance diagram for Ifpack2::Chebyshev< MatrixType >:

Public Member Functions

	Chebyshev (const Teuchos::RCP< const Tpetra::RowMatrix< Scalar, LocalOrdinal, GlobalOrdinal, Node > > &A)
	Chebyshev constructor with given Tpetra::RowMatrix input.
virtual	~Chebyshev ()
	Chebyshev destructor.

void	setParameters (const Teuchos::ParameterList &params)
	Sets all the parameters for the preconditioner.
void	initialize ()
	Initialize.
bool	isInitialized () const
	Returns `true` if the preconditioner has been successfully initialized.
void	compute ()
	Computes the preconditioner.
bool	isComputed () const
	If preconditioner is computed, this query returns true, otherwise it returns false.
Methods implementing a Tpetra::Operator interface.
void	apply (const Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &X, Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &Y, Teuchos::ETransp mode=Teuchos::NO_TRANS, Scalar alpha=Teuchos::ScalarTraits< Scalar >::one(), Scalar beta=Teuchos::ScalarTraits< Scalar >::zero()) const
	Applies the preconditioner to X, returns the result in Y.
const Teuchos::RCP< const Tpetra::Map< LocalOrdinal, GlobalOrdinal, Node > > &	getDomainMap () const
	Returns the Tpetra::Map object associated with the domain of this operator.
const Teuchos::RCP< const Tpetra::Map< LocalOrdinal, GlobalOrdinal, Node > > &	getRangeMap () const
	Returns the Tpetra::Map object associated with the range of this operator.
bool	hasTransposeApply () const
void	applyMat (const Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &X, Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &Y, Teuchos::ETransp mode=Teuchos::NO_TRANS) const
	Applies the matrix to a Tpetra::MultiVector.
Mathematical functions.
magnitudeType	computeCondEst (CondestType CT=Cheap, LocalOrdinal MaxIters=1550, magnitudeType Tol=1e-9, const Teuchos::Ptr< const Tpetra::RowMatrix< Scalar, LocalOrdinal, GlobalOrdinal, Node > > &matrix=Teuchos::null)
	Computes the estimated condition number and returns the value.
Attribute accessor methods
magnitudeType	getCondEst () const
	Returns the computed estimated condition number, or -1.0 if no computed.
const Teuchos::RCP< const Teuchos::Comm< int > > &	getComm () const
	Returns the Tpetra::BlockMap object associated with the range of this matrix operator.
Teuchos::RCP< const Tpetra::RowMatrix< Scalar, LocalOrdinal, GlobalOrdinal, Node > >	getMatrix () const
	Returns a reference to the matrix to be preconditioned.
double	getComputeFlops () const
	Returns the number of flops in the computation phase.
double	getApplyFlops () const
	Returns the number of flops for the application of the preconditioner.
int	getNumInitialize () const
	Returns the number of calls to initialize().
int	getNumCompute () const
	Returns the number of calls to compute().
int	getNumApply () const
	Returns the number of calls to apply().
double	getInitializeTime () const
	Returns the time spent in initialize().
double	getComputeTime () const
	Returns the time spent in compute().
double	getApplyTime () const
	Returns the time spent in apply().
Overridden from Teuchos::Describable
std::string	description () const
	Return a simple one-line description of this object.
void	describe (Teuchos::FancyOStream &out, const Teuchos::EVerbosityLevel verbLevel=Teuchos::Describable::verbLevel_default) const
	Print the object with some verbosity level to an FancyOStream object.
Static Public Member Functions

static void	PowerMethod (const Tpetra::Operator< Scalar, LocalOrdinal, GlobalOrdinal, Node > &Operator, const Tpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &InvPointDiagonal, const int MaximumIterations, Scalar &LambdaMax)
	Simple power method to compute lambda_max.
static void	CG (const Tpetra::Operator< Scalar, LocalOrdinal, GlobalOrdinal, Node > &Operator, const Tpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &InvPointDiagonal, const int MaximumIterations, Scalar &lambda_min, Scalar &lambda_max)
	Not currently implemented: Use CG to estimate lambda_min and lambda_max.

Detailed Description

template<class MatrixType>
class Ifpack2::Chebyshev< MatrixType >

A class for preconditioning with Chebyshev polynomials.

Ifpack2::Chebyshev enables the construction of preconditioners based on Chebyshev polynomials for a Tpetra::RowMatrix. Ifpack2::Chebyshev is derived from the Ifpack2::Preconditioner class, which is itself derived from Tpetra::Operator. Therefore this object can be used as preconditioner everywhere an apply() method is required in the preconditioning step.

The class is an adaptation of the routine ML_Cheby in Smoother/ml_smoother.hpp

(04/04/06) Flops are not counted in the routine apply()

For the list of parameters, see the Chebyshev::setParameters method.

Author:: Ulrich Hetmaniuk. SNL 1416.

Date:: Last modified on 04-Apr-06.

Constructor & Destructor Documentation

template<class MatrixType >

Ifpack2::Chebyshev< MatrixType >::Chebyshev ( const Teuchos::RCP< const Tpetra::RowMatrix< Scalar, LocalOrdinal, GlobalOrdinal, Node > > & A ) [explicit]

Chebyshev constructor with given Tpetra::RowMatrix input.

template<class MatrixType >

Ifpack2::Chebyshev< MatrixType >::~Chebyshev ( ) [virtual]

Chebyshev destructor.

Member Function Documentation

template<class MatrixType >

void Ifpack2::Chebyshev< MatrixType >::setParameters ( const Teuchos::ParameterList & params ) [virtual]

Sets all the parameters for the preconditioner.

Valid parameters include the following:

"chebyshev: ratio eigenvalue" (Scalar)
this is the ratio to define the lower bound on the spectrum; lambda^* = LambdaMax / EigRatio; a typical value used in ML is 30.0 (30.0 is the default value).
"chebyshev: min eigenvalue" (Scalar)
this is the smallest eigenvalue; this parameter is optional and is only accessed to check whether the input matrix is equal to identity.
"chebyshev: max eigenvalue" (Scalar)
this is the largest eigenvalue of the matrix.
"chebyshev: degree" (int)
this is the polynomial degree.
"chebyshev: min diagonal value" (Scalar)
this defines the threshold for diagonal values under which they are not inverted
"chebyshev: zero starting solution" (bool)
Determines whether the 'x' vector is zero'd on entry to Chebyshev::apply.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

void Ifpack2::Chebyshev< MatrixType >::initialize ( ) [virtual]

Initialize.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType>

bool Ifpack2::Chebyshev< MatrixType >::isInitialized ( ) const [inline, virtual]

Returns true if the preconditioner has been successfully initialized.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

void Ifpack2::Chebyshev< MatrixType >::compute ( ) [virtual]

Computes the preconditioner.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType>

bool Ifpack2::Chebyshev< MatrixType >::isComputed ( ) const [inline, virtual]

If preconditioner is computed, this query returns true, otherwise it returns false.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType>

void Ifpack2::Chebyshev< MatrixType >::apply	(	const Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	X,
		Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	Y,
		Teuchos::ETransp	mode = `Teuchos::NO_TRANS`,
		Scalar	alpha = `Teuchos::ScalarTraits<Scalar>::one()`,
		Scalar	beta = `Teuchos::ScalarTraits<Scalar>::zero()`
	)		const `[virtual]`

Applies the preconditioner to X, returns the result in Y.

Parameters:

X	- (In) A Tpetra::MultiVector of dimension NumVectors to be preconditioned.
Y	- (InOut) A Tpetra::_MultiVector of dimension NumVectors containing result.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

const Teuchos::RCP< const Tpetra::Map< typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type > > & Ifpack2::Chebyshev< MatrixType >::getDomainMap ( ) const [virtual]

Returns the Tpetra::Map object associated with the domain of this operator.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

const Teuchos::RCP< const Tpetra::Map< typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type > > & Ifpack2::Chebyshev< MatrixType >::getRangeMap ( ) const [virtual]

Returns the Tpetra::Map object associated with the range of this operator.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType>

void Ifpack2::Chebyshev< MatrixType >::applyMat	(	const Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	X,
		Tpetra::MultiVector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	Y,
		Teuchos::ETransp	mode = `Teuchos::NO_TRANS`
	)		const

Applies the matrix to a Tpetra::MultiVector.

Parameters:

X	- (In) A Tpetra::MultiVector of dimension NumVectors to multiply with matrix.
Y	- (Out) A Tpetra::MultiVector of dimension NumVectors containing the result.

template<class MatrixType >

Teuchos::ScalarTraits< typename MatrixType::scalar_type >::magnitudeType Ifpack2::Chebyshev< MatrixType >::computeCondEst	(	CondestType	CT = `Cheap`,
		LocalOrdinal	MaxIters = `1550`,
		magnitudeType	Tol = `1e-9`,
		const Teuchos::Ptr< const Tpetra::RowMatrix< Scalar, LocalOrdinal, GlobalOrdinal, Node > > &	matrix = `Teuchos::null`
	)		`[virtual]`

Computes the estimated condition number and returns the value.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

Teuchos::ScalarTraits< typename MatrixType::scalar_type >::magnitudeType Ifpack2::Chebyshev< MatrixType >::getCondEst ( ) const [virtual]

Returns the computed estimated condition number, or -1.0 if no computed.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

const Teuchos::RCP< const Teuchos::Comm< int > > & Ifpack2::Chebyshev< MatrixType >::getComm ( ) const

Returns the Tpetra::BlockMap object associated with the range of this matrix operator.

template<class MatrixType >

Teuchos::RCP< const Tpetra::RowMatrix< typename MatrixType::scalar_type, typename MatrixType::local_ordinal_type, typename MatrixType::global_ordinal_type, typename MatrixType::node_type > > Ifpack2::Chebyshev< MatrixType >::getMatrix ( ) const [virtual]

Returns a reference to the matrix to be preconditioned.

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

double Ifpack2::Chebyshev< MatrixType >::getComputeFlops ( ) const

Returns the number of flops in the computation phase.

template<class MatrixType >

double Ifpack2::Chebyshev< MatrixType >::getApplyFlops ( ) const

Returns the number of flops for the application of the preconditioner.

template<class MatrixType >

int Ifpack2::Chebyshev< MatrixType >::getNumInitialize ( ) const [virtual]

Returns the number of calls to initialize().

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

int Ifpack2::Chebyshev< MatrixType >::getNumCompute ( ) const [virtual]

Returns the number of calls to compute().

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

int Ifpack2::Chebyshev< MatrixType >::getNumApply ( ) const [virtual]

Returns the number of calls to apply().

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

double Ifpack2::Chebyshev< MatrixType >::getInitializeTime ( ) const [virtual]

Returns the time spent in initialize().

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

double Ifpack2::Chebyshev< MatrixType >::getComputeTime ( ) const [virtual]

Returns the time spent in compute().

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

double Ifpack2::Chebyshev< MatrixType >::getApplyTime ( ) const [virtual]

Returns the time spent in apply().

Implements Ifpack2::Preconditioner< MatrixType::scalar_type, MatrixType::local_ordinal_type, MatrixType::global_ordinal_type, MatrixType::node_type >.

template<class MatrixType >

std::string Ifpack2::Chebyshev< MatrixType >::description ( ) const

Return a simple one-line description of this object.

template<class MatrixType >

void Ifpack2::Chebyshev< MatrixType >::describe	(	Teuchos::FancyOStream &	out,
		const Teuchos::EVerbosityLevel	verbLevel = `Teuchos::Describable::verbLevel_default`
	)		const

Print the object with some verbosity level to an FancyOStream object.

template<class MatrixType>

void Ifpack2::Chebyshev< MatrixType >::PowerMethod	(	const Tpetra::Operator< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	Operator,
		const Tpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	InvPointDiagonal,
		const int	MaximumIterations,
		Scalar &	LambdaMax
	)		`[static]`

Simple power method to compute lambda_max.

template<class MatrixType >

void Ifpack2::Chebyshev< MatrixType >::CG	(	const Tpetra::Operator< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	Operator,
		const Tpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > &	InvPointDiagonal,
		const int	MaximumIterations,
		Scalar &	lambda_min,
		Scalar &	lambda_max
	)		`[static]`

Not currently implemented: Use CG to estimate lambda_min and lambda_max.

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

Public Member Functions

Static Public Member Functions

Detailed Description

template<class MatrixType> class Ifpack2::Chebyshev< MatrixType >

Constructor & Destructor Documentation

Member Function Documentation

template<class MatrixType>
class Ifpack2::Chebyshev< MatrixType >