Stub adaptor from Thyra::MultiVectorBase to TSQR. More...

#include <Thyra_TsqrAdaptor.hpp>

Inheritance diagram for Thyra::TsqrAdaptor< Scalar >:

Public Types
typedef Thyra::MultiVectorBase < Scalar >	MV

typedef Scalar	scalar_type

typedef int	ordinal_type

typedef Teuchos::SerialDenseMatrix < ordinal_type, scalar_type >	dense_matrix_type

typedef Teuchos::ScalarTraits < scalar_type >::magnitudeType	magnitude_type

Public Member Functions
	TsqrAdaptor (const Teuchos::RCP< Teuchos::ParameterList > &)
	Constructor (that accepts a parameter list). More...

	TsqrAdaptor ()
	Constructor (that uses default parameters). More...

Teuchos::RCP< const Teuchos::ParameterList >	getValidParameters () const

void	setParameterList (const Teuchos::RCP< Teuchos::ParameterList > &)

void	factorExplicit (MV &, MV &, dense_matrix_type &, const bool=false)
	Compute QR factorization [Q,R] = qr(A,0). More...

int	revealRank (MV &, dense_matrix_type &, const magnitude_type &)
	Rank-revealing decomposition. More...

Public Member Functions inherited from Teuchos::ParameterListAcceptorDefaultBase
RCP< ParameterList >	getNonconstParameterList ()

RCP< ParameterList >	unsetParameterList ()

RCP< const ParameterList >	getParameterList () const

Private Member Functions
void	prepareDistTsqr (const MV &)
	Finish interprocess TSQR initialization. More...

void	prepareTsqr (const MV &)
	Finish TSQR initialization. More...

Static Private Member Functions
static Teuchos::RCP< const Teuchos::Comm< int > >	getComm (const MV &X)
	Attempt to get a communicator out of the given multivector. More...

Additional Inherited Members
Protected Member Functions inherited from Teuchos::ParameterListAcceptorDefaultBase
void	setMyParamList (const RCP< ParameterList > &paramList)

RCP< ParameterList >	getMyNonconstParamList ()

RCP< const ParameterList >	getMyParamList () const

Detailed Description

template<class Scalar>
class Thyra::TsqrAdaptor< Scalar >

Stub adaptor from Thyra::MultiVectorBase to TSQR.

TSQR (Tall Skinny QR factorization) is an orthogonalization kernel that is as accurate as Householder QR, yet requires only $2 \log P$ messages between $P$ MPI processes, independently of the number of columns in the multivector.

TSQR works independently of the particular multivector implementation, and interfaces to the latter via an adaptor class. This class is the adaptor class for MultiVectorBase. It templates on the MultiVector (MV) type so that it can pick up that class' typedefs. In particular, TSQR chooses its intranode implementation based on the Kokkos Node type of the multivector.

Warning: This is a stub adaptor that just placates the compiler and does nothing. It's not hard to implement a Thyra adaptor, but in order for the adaptor to be efficient, it requires special cases for extracting the actual multivector implementation (e.g., Epetra_MultiVector or Tpetra::MultiVector) out of the Thyra wrapper.

Definition at line 54 of file Thyra_TsqrAdaptor.hpp.

Member Typedef Documentation

template<class Scalar >

typedef Thyra::MultiVectorBase<Scalar> Thyra::TsqrAdaptor< Scalar >::MV

Definition at line 56 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

typedef Scalar Thyra::TsqrAdaptor< Scalar >::scalar_type

Definition at line 57 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

typedef int Thyra::TsqrAdaptor< Scalar >::ordinal_type

Definition at line 58 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

typedef Teuchos::SerialDenseMatrix<ordinal_type, scalar_type> Thyra::TsqrAdaptor< Scalar >::dense_matrix_type

Definition at line 59 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

typedef Teuchos::ScalarTraits<scalar_type>::magnitudeType Thyra::TsqrAdaptor< Scalar >::magnitude_type

Definition at line 60 of file Thyra_TsqrAdaptor.hpp.

Constructor & Destructor Documentation

template<class Scalar >

Thyra::TsqrAdaptor< Scalar >::TsqrAdaptor ( const Teuchos::RCP< Teuchos::ParameterList > & )

inline

Constructor (that accepts a parameter list).

Parameters

plist [in] List of parameters for configuring TSQR. The specific parameter keys that are read depend on the TSQR implementation. For details, call getValidParameters() and examine the documentation embedded therein.

Definition at line 68 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

Thyra::TsqrAdaptor< Scalar >::TsqrAdaptor ( )

inline

Constructor (that uses default parameters).

Definition at line 74 of file Thyra_TsqrAdaptor.hpp.

Member Function Documentation

template<class Scalar >

Teuchos::RCP<const Teuchos::ParameterList> Thyra::TsqrAdaptor< Scalar >::getValidParameters ( ) const

inlinevirtual

Reimplemented from Teuchos::ParameterListAcceptor.

Definition at line 80 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

void Thyra::TsqrAdaptor< Scalar >::setParameterList ( const Teuchos::RCP< Teuchos::ParameterList > & )

inlinevirtual

Implements Teuchos::ParameterListAcceptor.

Definition at line 86 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

void Thyra::TsqrAdaptor< Scalar >::factorExplicit	(	MV &	,
		MV &	,
		dense_matrix_type &	,
		const bool	= `false`
	)

inline

Compute QR factorization [Q,R] = qr(A,0).

Parameters

A	[in/out] On input: the multivector to factor. Overwritten with garbage on output.
Q	[out] On output: the (explicitly stored) Q factor in the QR factorization of the (input) multivector A.
R	[out] On output: the R factor in the QR factorization of the (input) multivector A.
forceNonnegativeDiagonal	[in] If true, then (if necessary) do extra work (modifying both the Q and R factors) in order to force the R factor to have a nonnegative diagonal.

Warning: Currently, this method only works if A and Q have the same communicator and row distribution ("map," in Petra terms) as those of the multivector given to this TsqrAdaptor instance's constructor. Otherwise, the result of this method is undefined.

Definition at line 113 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

int Thyra::TsqrAdaptor< Scalar >::revealRank	(	MV &	,
		dense_matrix_type &	,
		const magnitude_type &
	)

inline

Rank-revealing decomposition.

Using the R factor and explicit Q factor from factorExplicit(), compute the singular value decomposition (SVD) of R ( $R = U \Sigma V^*$ ). If R is full rank (with respect to the given relative tolerance tol), don't change Q or R. Otherwise, compute $Q := Q \cdot U$ and $R := \Sigma V^*$ in place (the latter may be no longer upper triangular).

Parameters

Q	[in/out] On input: explicit Q factor computed by factorExplicit(). (Must be an orthogonal resp. unitary matrix.) On output: If R is of full numerical rank with respect to the tolerance tol, Q is unmodified. Otherwise, Q is updated so that the first rank columns of Q are a basis for the column space of A (the original matrix whose QR factorization was computed by factorExplicit()). The remaining columns of Q are a basis for the null space of A.
R	[in/out] On input: ncols by ncols upper triangular matrix with leading dimension ldr >= ncols. On output: if input is full rank, R is unchanged on output. Otherwise, if $R = U \Sigma V^$ is the SVD of R, on output R is overwritten with $ V^$. This is also an ncols by ncols matrix, but may not necessarily be upper triangular.
tol	[in] Relative tolerance for computing the numerical rank of the matrix R.

Returns: Rank of R: $0 \leq r \leq ncols$ .

Definition at line 152 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

static Teuchos::RCP<const Teuchos::Comm<int> > Thyra::TsqrAdaptor< Scalar >::getComm ( const MV & X )

inlinestaticprivate

Attempt to get a communicator out of the given multivector.

This only works if the multivector's range (VectorSpaceBase) is actually an SpmdVectorSpaceBase object, and if that object's Comm is either an MpiComm (in an MPI build) or a SerialComm (in either an MPI build or a no-MPI build).

If the attempt does not succeed, this method throws std::runtime_error. If it does succeed, it returns the (suitably wrapped) communicator.

Definition at line 171 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

void Thyra::TsqrAdaptor< Scalar >::prepareDistTsqr ( const MV & )

inlineprivate

Finish interprocess TSQR initialization.

Input X is a valid Thyra::MultiVectorBase instance whose communicator wrapper we will use to prepare TSQR. It is not modified.

Note: It's OK to call this method more than once; it is idempotent.

This method may fail if MV is not the right kind of multivector, that is, if it does not have a communicator or if we don't know how to extract a communicator from it. If it fails in this way, it will throw std::runtime_error.

Definition at line 249 of file Thyra_TsqrAdaptor.hpp.

template<class Scalar >

void Thyra::TsqrAdaptor< Scalar >::prepareTsqr ( const MV & )

inlineprivate

Finish TSQR initialization.

The intranode and internode TSQR implementations both have a two-stage initialization procedure: first, setting parameters (which may happen at construction), and second, getting information they need from the multivector input in order to finish initialization. For intranode TSQR, this may include the Kokkos Node instance; for internode TSQR, this includes the communicator. The second stage of initialization happens in this class' computational routines; all of those routines accept one or more multivector inputs, which this method can use for finishing initialization. Thus, users of this class never need to see the two-stage initialization.

Parameters

X	[in] Multivector object, used only to access the underlying communicator object (in this case, the Teuchos::Comm<int>) and (possibly) the Kokkos Node instance. All multivector objects used with this adapter must have the same communicator and Kokkos Node instance (if applicable).

Definition at line 271 of file Thyra_TsqrAdaptor.hpp.

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

Thyra_TsqrAdaptor.hpp

Public Types

Public Member Functions

Private Member Functions

Static Private Member Functions

Additional Inherited Members

Detailed Description

template<class Scalar> class Thyra::TsqrAdaptor< Scalar >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

template<class Scalar>
class Thyra::TsqrAdaptor< Scalar >