Subclass of Belos::Iteration for GMRES-based solvers. More...

#include <BelosGmresBaseIteration.hpp>

Inheritance diagram for Belos::GmresBaseIteration< Scalar, MV, OP >:

Public Types
typedef Scalar	scalar_type
typedef Teuchos::ScalarTraits < Scalar >::magnitudeType	magnitude_type
typedef MV	multivector_type
typedef OP	operator_type
Public Member Functions
void	iterate ()
	Iterate until error or status test triggers.
void	initialize ()
	Initialize the solver.
int	getNumIters () const
	Return the current iteration count.
void	resetNumIters (int iter=0)
	Reset the iteration count to iter.
void	restart ()
	Restart GMRES.
Teuchos::RCP< const MV >	getNativeResiduals (std::vector< magnitude_type > *norms) const
	Get the residuals native to the solver.
Teuchos::RCP< MV >	getCurrentUpdate () const
	Force computation of the current solution update, if it has not already yet been computed.
const LinearProblem< Scalar, MV, OP > &	getProblem () const
	Get a constant reference to the linear problem.
int	getBlockSize () const
	The block size to be used by the iterative solver in solving this linear problem.
void	setBlockSize (int blockSize)
	Set blocksize (not allowed unless blockSize==1)
bool	isInitialized ()
	Whether or not the solver has been initialized.
	GmresBaseIteration (const Teuchos::RCP< LinearProblem< Scalar, MV, OP > > &problem, const Teuchos::RCP< const OrthoManager< Scalar, MV > > &ortho, const Teuchos::RCP< OutputManager< Scalar > > &printer, const Teuchos::RCP< StatusTest< Scalar, MV, OP > > &tester, const Teuchos::RCP< const Teuchos::ParameterList > &params)
	Constructor.
virtual	~GmresBaseIteration ()
	Trivial destructor.
void	updateSolution ()
	Update the current approximate solution.

Detailed Description

template<class Scalar, class MV, class OP>
class Belos::GmresBaseIteration< Scalar, MV, OP >

Subclass of Belos::Iteration for GMRES-based solvers.

Author:: Mark Hoemmen

Warning:: This is EXPERIMENTAL CODE. DO NOT RELY ON THIS CODE. The interface or implementation may change at any time.

Note:: Belos already has a GmresIteration subclass of Iteration, so we named this class GmresBaseIteration, to indicate that it is implemented using GmresBase.

Definition at line 65 of file BelosGmresBaseIteration.hpp.

Member Typedef Documentation

template<class Scalar , class MV , class OP >

typedef Scalar Belos::GmresBaseIteration< Scalar, MV, OP >::scalar_type

Definition at line 72 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

typedef Teuchos::ScalarTraits<Scalar>::magnitudeType Belos::GmresBaseIteration< Scalar, MV, OP >::magnitude_type

Definition at line 73 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

typedef MV Belos::GmresBaseIteration< Scalar, MV, OP >::multivector_type

Definition at line 74 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

typedef OP Belos::GmresBaseIteration< Scalar, MV, OP >::operator_type

Definition at line 75 of file BelosGmresBaseIteration.hpp.

Constructor & Destructor Documentation

template<class Scalar , class MV , class OP >

Belos::GmresBaseIteration< Scalar, MV, OP >::GmresBaseIteration	(	const Teuchos::RCP< LinearProblem< Scalar, MV, OP > > &	problem,
		const Teuchos::RCP< const OrthoManager< Scalar, MV > > &	ortho,
		const Teuchos::RCP< OutputManager< Scalar > > &	printer,
		const Teuchos::RCP< StatusTest< Scalar, MV, OP > > &	tester,
		const Teuchos::RCP< const Teuchos::ParameterList > &	params
	)

Constructor.

Parameters:

problem	[in/out] The linear problem to solve, along with any preconditioner(s)
ortho	[in] Orthogonalization manager
printer	[in/out] Output manager
tester	[in] Status test for stopping iteration
params	[in(/out???)] Parameters and options for GMRES. An important parameter, required for correctness if the preconditioner might change from iteration to iteration, is the "Flexible" boolean parameter which tells us whether or not to run Flexible GMRES.

Note:: Other Belos solvers take a MatOrthoManager instead of an OrthoManager. This iteration doesn't use the "Mat" features, so we only take an OrthoManager.

Definition at line 327 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

virtual Belos::GmresBaseIteration< Scalar, MV, OP >::~GmresBaseIteration ( ) [inline, virtual]

Trivial destructor.

Definition at line 273 of file BelosGmresBaseIteration.hpp.

Member Function Documentation

template<class Scalar , class MV , class OP >

void Belos::GmresBaseIteration< Scalar, MV, OP >::iterate ( ) [inline, virtual]

Iterate until error or status test triggers.

Note:: (mfh 30 Dec 2010) The convention in Belos, for some reason, is that iterate() does not call updateSolution() on the LinearProblem instance. In fact, getCurrentUpdate() doesn't even do that. Iteration subclasses that implement GMRES simply don't call updateSolution() on the LinearProblem instance. Instead, the solution manager first calls getCurrentUpdate() on the Iteration subclass instance, and then calls updateSolution(update,true) on the LinearProblem instance. This is a reasonable convention.; (mfh 30 Dec 2010) Nevertheless, Belos' (block) GMRES solution manager's solve() method is messy and invasive of the Iteration subclass' state. For example, the Iteration should be responsible for the mechanics of restarting, not the solution manager. The Iteration has the LinearProblem instance anyway, so it should call updateSolution() before the restart.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 97 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

void Belos::GmresBaseIteration< Scalar, MV, OP >::initialize ( ) [virtual]

Initialize the solver.

Note:: This Iteration subclass assumes that the linear problem is ready to solve, i.e., that the matrix, any preconditioner(s), and right-hand side have been set.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 343 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

int Belos::GmresBaseIteration< Scalar, MV, OP >::getNumIters ( ) const [inline, virtual]

Return the current iteration count.

Restarting resets the current iteration count.

Note:: The first iteration (after the initial residual computation) counts as 1. Belos likes to measure the iterations while they are in progress, not after they are done (when we increment them. That's why we add one in the code below.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 127 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

void Belos::GmresBaseIteration< Scalar, MV, OP >::resetNumIters ( int iter = 0 ) [inline, virtual]

Reset the iteration count to iter.

Reset the iteration count to iter, typically zero (the default value).

Parameters:

iter	[in] New iteration count (>= 0)

Note:: The implementation actually saves state up to and including iteration number iter, by "backing out" state beyond that iteration. Iterations may be resumed from there. Thus it promises more than the Iteration interface, which reserves the right to invalidate all iteration state (???).

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 141 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

void Belos::GmresBaseIteration< Scalar, MV, OP >::restart ( ) [inline]

Restart GMRES.

Definition at line 149 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

Teuchos::RCP<const MV> Belos::GmresBaseIteration< Scalar, MV, OP >::getNativeResiduals ( std::vector< magnitude_type > * norms ) const [inline]

Get the residuals native to the solver.

Parameters:

norms [out] norms[j] is set to the "native" residual norm for the j-th residual vector. (This is not block Arnoldi, so blockSize==1 always, and there should only be one residual vector.)

Returns:: Optionally, a multivector with blockSize vectors containing the native residuals. Subclasses reserve the right to return Teuchos::null.

Note:: The Iteration interface requires that this method be const. However, we reserve the right to cache computed results.; (mfh 30 Dec 2010) Belos::StatusTestGenResNorm's checkStatus() method (re)computes the norms (using a norm of its own specification, like the 1-norm, 2-norm, etc. -- but not a general norm, since it calls MVT::MvNorm() to do the work) if this method returns non-null. If it returns null, StatusTestGenResNorm's checkStatus() method uses the "norms" parameter. It never calls getNativeResiduals(NULL). This is a waste, since GmresBase is always able to return a native residual vector _and_ a native residual norm. Iteration should really have two separate pure virtual methods: getNativeResidualVector() and getNativeResidualNorm().

Definition at line 183 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

Teuchos::RCP<MV> Belos::GmresBaseIteration< Scalar, MV, OP >::getCurrentUpdate ( ) const [inline, virtual]

Force computation of the current solution update, if it has not already yet been computed.

Returns:: Current approximate solution update

Note:: The Iteration interface requires that this method be const, but we reserve the right to cache the current solution update.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 214 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

const LinearProblem<Scalar, MV, OP>& Belos::GmresBaseIteration< Scalar, MV, OP >::getProblem ( ) const [inline, virtual]

Get a constant reference to the linear problem.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 219 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

int Belos::GmresBaseIteration< Scalar, MV, OP >::getBlockSize ( ) const [inline, virtual]

The block size to be used by the iterative solver in solving this linear problem.

Our GMRES/Arnoldi implementations only solve for one right-hand side at a time, so the block size is always one.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 225 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

void Belos::GmresBaseIteration< Scalar, MV, OP >::setBlockSize ( int blockSize ) [inline, virtual]

Set blocksize (not allowed unless blockSize==1)

Set the block size to use when solving this linear problem. The Arnoldi/GMRES implementations used by this Iteration subclass can only solve for one right-hand side at a time, so the block size must always be one. We deal with this hackishly by raising an std::invalid_argument if a non-1 input is given. (It's hackish because it violates the "is-a" requirement of class hierarchies; GmresBaseIteration "is not an" Iteration, because it does not support arbitrary block sizes.)

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 238 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

bool Belos::GmresBaseIteration< Scalar, MV, OP >::isInitialized ( ) [inline, virtual]

Whether or not the solver has been initialized.

Implements Belos::Iteration< Scalar, MV, OP >.

Definition at line 246 of file BelosGmresBaseIteration.hpp.

template<class Scalar , class MV , class OP >

void Belos::GmresBaseIteration< Scalar, MV, OP >::updateSolution ( ) [inline]

Update the current approximate solution.

Modify the LinearProblem instance's current approximate solution (the multivector returned by getLHS()) by adding in the current solution update (xUpdate_). Tell the LinearProblem to compute a new residual vector as well.

Definition at line 282 of file BelosGmresBaseIteration.hpp.

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

BelosGmresBaseIteration.hpp

Public Types

Public Member Functions

Detailed Description

template<class Scalar, class MV, class OP> class Belos::GmresBaseIteration< Scalar, MV, OP >

Member Typedef Documentation

Constructor & Destructor Documentation

Member Function Documentation

template<class Scalar, class MV, class OP>
class Belos::GmresBaseIteration< Scalar, MV, OP >