Ifpack2::Diagonal< MatrixType > Class Template Reference

A class for diagonal preconditioning. More...

#include <Ifpack2_Diagonal_decl.hpp>

Inheritance diagram for Ifpack2::Diagonal< MatrixType >:

List of all members.

Public Member Functions
	Diagonal (const Teuchos::RCP< const MatrixType > &A)
	Constructor to create a Diagonal preconditioner using a Tpetra::CrsMatrix.
	Diagonal (const Teuchos::RCP< const Tpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > > &diag)
	Constructor to create a Diagonal preconditioner using a Tpetra::Vector.
virtual	~Diagonal ()
	Destructor.
void	setParameters (const Teuchos::ParameterList &params)
	Sets parameters on this object.
void	initialize ()
	Initialize.
bool	isInitialized () const
	Returns true if the preconditioner has been successfully initialized.
void	compute ()
	compute the preconditioner
bool	isComputed () const
	Return true if compute() has been called.
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.
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.

---

Detailed Description

template<class MatrixType>
class Ifpack2::Diagonal< MatrixType >

A class for diagonal preconditioning.

Ifpack2::Diagonal wraps a vector as a diagonal preconditioner. The preconditioner is simply defined by

\[ z_i = D_i r_i, \]

where \(r,z\) are the vector to be preconditioned and the preconditioned vector, and \(D_i\) is the i-th element of the scaling vector.

When Ifpack2::Diagonal is constructed with a matrix, \(D\) contains the inverted diagonal elements from the matrix.

When Ifpack2::Diagonal is constructed with a vector, \(D\) is the caller-supplied vector.

Author:

Michael Heroux, ETHZ/D-INFK

Date:

Ifpack2 conversion (from Ifpack code) 31-Mar-2010

---

Constructor & Destructor Documentation

template<class MatrixType >

Ifpack2::Diagonal< MatrixType >::Diagonal

(

const Teuchos::RCP< const MatrixType > &

A

)

Constructor to create a Diagonal preconditioner using a Tpetra::CrsMatrix.

template<class MatrixType >

Ifpack2::Diagonal< MatrixType >::Diagonal

(

const Teuchos::RCP< const Tpetra::Vector< Scalar, LocalOrdinal, GlobalOrdinal, Node > > &

diag

)

Constructor to create a Diagonal preconditioner using a Tpetra::Vector.

If your compiler complains about this constructor being ambigous with the other constructor overload, instead call the free-standing function Ifpack2::createDiagonalPreconditioner which is located at the bottom of this header file. (This issue arises if this constructor is called with a RCP<Tpetra::Vector> that isn't const-qualified exactly as declared here.)

template<class MatrixType >

Ifpack2::Diagonal< MatrixType >::~Diagonal

(

)

[virtual]

Destructor.

---

Member Function Documentation

template<class MatrixType >

void Ifpack2::Diagonal< MatrixType >::setParameters

(

const Teuchos::ParameterList &

params

)

[virtual]

Sets parameters on this object.

Currently doesn't need any parameters.

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

template<class MatrixType >

void Ifpack2::Diagonal< 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::Diagonal< 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::Diagonal< MatrixType >::compute

(

)

[virtual]

compute the preconditioner

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

template<class MatrixType >

bool Ifpack2::Diagonal< MatrixType >::isComputed

(

)

const [inline, virtual]

Return true if compute() has been called.

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

template<class MatrixType >

void Ifpack2::Diagonal< 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.

Returns:

Integer error code, set to 0 if successful.

Warning:

This routine is NOT AztecOO compliant.

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<LocalOrdinal,GlobalOrdinal,Node> >& Ifpack2::Diagonal< MatrixType >::getDomainMap

(

)

const [inline, 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<LocalOrdinal,GlobalOrdinal,Node> >& Ifpack2::Diagonal< MatrixType >::getRangeMap

(

)

const [inline, 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::Diagonal< 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::Diagonal< 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 >

magnitudeType Ifpack2::Diagonal< MatrixType >::getCondEst

(

)

const [inline, 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::Diagonal< MatrixType >::getComm

(

)

const

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

template<class MatrixType >

Teuchos::RCP<const Tpetra::RowMatrix<Scalar,LocalOrdinal,GlobalOrdinal,Node> > Ifpack2::Diagonal< MatrixType >::getMatrix

(

)

const [inline, 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::Diagonal< MatrixType >::getComputeFlops

(

)

const

Returns the number of flops in the computation phase.

template<class MatrixType >

double Ifpack2::Diagonal< MatrixType >::getApplyFlops

(

)

const

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

template<class MatrixType >

int Ifpack2::Diagonal< 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::Diagonal< 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::Diagonal< 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::Diagonal< 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::Diagonal< 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::Diagonal< 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::Diagonal< MatrixType >::description

(

)

const

Return a simple one-line description of this object.

template<class MatrixType >

void Ifpack2::Diagonal< 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.

---

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

• Ifpack2_Diagonal_decl.hpp
• Ifpack2_Diagonal_def.hpp