This class implements the RCG iteration, where a single-std::vector Krylov subspace is constructed. More...

#include <BelosRCGIter.hpp>

Inheritance diagram for Belos::RCGIter< ScalarType, MV, OP, DM >:

[legend]

Public Types
typedef MultiVecTraits< ScalarType, MV, DM >	MVT

typedef OperatorTraits< ScalarType, MV, OP >	OPT

typedef DenseMatTraits< ScalarType, DM >	DMT

typedef Teuchos::ScalarTraits< ScalarType >	SCT

typedef SCT::magnitudeType	MagnitudeType

Public Member Functions
Constructors/Destructor
	RCGIter (const Teuchos::RCP< LinearProblem< ScalarType, MV, OP, DM > > &problem, const Teuchos::RCP< OutputManager< ScalarType > > &printer, const Teuchos::RCP< StatusTest< ScalarType, MV, OP, DM > > &tester, Teuchos::ParameterList &params)
	RCGIter constructor with linear problem, solver utilities, and parameter list of solver options.

virtual	~RCGIter ()
	Destructor.

Solver methods
void	iterate ()
	This method performs RCG iterations until the status test indicates the need to stop or an error occurs (in which case, an std::exception is thrown).

void	initialize (RCGIterState< ScalarType, MV, DM > &newstate)
	Initialize the solver to an iterate, providing a complete state.

void	initialize ()
	Initialize the solver with the initial vectors from the linear problem or random data.

Status methods
int	getNumIters () const
	Get the current iteration count.

void	resetNumIters (int iter=0)
	Reset the iteration count.

Teuchos::RCP< const MV >	getNativeResiduals (std::vector< MagnitudeType > *) const
	Get the norms of the residuals native to the solver.

Teuchos::RCP< MV >	getCurrentUpdate () const
	Get the current update to the linear system.

int	getCurSubspaceDim () const
	Get the dimension of the search subspace used to generate the current solution to the linear problem.

int	getMaxSubspaceDim () const
	Get the maximum dimension allocated for the search subspace.

Public Member Functions inherited from Belos::Iteration< ScalarType, MV, OP, DM >
	Iteration ()
	Default Constructor.

virtual	~Iteration ()
	Destructor.

virtual Teuchos::RCP< const MV >	getNativeResiduals (std::vector< typename Teuchos::ScalarTraits< ScalarType >::magnitudeType > *norms) const=0
	Get the residuals native to the solver.

Accessor methods
const LinearProblem< ScalarType, MV, OP, DM > &	getProblem () const
	Get a constant reference to the linear problem.

int	getNumBlocks () const
	Get the maximum number of blocks used by the iterative solver in solving this linear problem.

void	setNumBlocks (int numBlocks)
	Set the maximum number of blocks used by the iterative solver.

int	getBlockSize () const
	Get the blocksize to be used by the iterative solver in solving this linear problem.

void	setBlockSize (int blockSize)
	Set the blocksize.

void	setSize (int recycleBlocks, int numBlocks)
	Set the maximum number of blocks used by the iterative solver and the number of recycled vectors.

bool	isInitialized ()
	States whether the solver has been initialized or not.

Detailed Description

template<class ScalarType, class MV, class OP, class DM>
class Belos::RCGIter< ScalarType, MV, OP, DM >

This class implements the RCG iteration, where a single-std::vector Krylov subspace is constructed.

Author: Michael Parks and Heidi Thornquist

Definition at line 110 of file BelosRCGIter.hpp.

Member Typedef Documentation

◆ MVT

template<class ScalarType , class MV , class OP , class DM >

typedef MultiVecTraits<ScalarType,MV,DM> Belos::RCGIter< ScalarType, MV, OP, DM >::MVT

Definition at line 117 of file BelosRCGIter.hpp.

◆ OPT

template<class ScalarType , class MV , class OP , class DM >

typedef OperatorTraits<ScalarType,MV,OP> Belos::RCGIter< ScalarType, MV, OP, DM >::OPT

Definition at line 118 of file BelosRCGIter.hpp.

◆ DMT

template<class ScalarType , class MV , class OP , class DM >

typedef DenseMatTraits<ScalarType,DM> Belos::RCGIter< ScalarType, MV, OP, DM >::DMT

Definition at line 119 of file BelosRCGIter.hpp.

◆ SCT

template<class ScalarType , class MV , class OP , class DM >

typedef Teuchos::ScalarTraits<ScalarType> Belos::RCGIter< ScalarType, MV, OP, DM >::SCT

Definition at line 120 of file BelosRCGIter.hpp.

◆ MagnitudeType

template<class ScalarType , class MV , class OP , class DM >

typedef SCT::magnitudeType Belos::RCGIter< ScalarType, MV, OP, DM >::MagnitudeType

Definition at line 121 of file BelosRCGIter.hpp.

Constructor & Destructor Documentation

◆ RCGIter()

template<class ScalarType , class MV , class OP , class DM >

Belos::RCGIter< ScalarType, MV, OP, DM >::RCGIter	(	const Teuchos::RCP< LinearProblem< ScalarType, MV, OP, DM > > &	problem,
		const Teuchos::RCP< OutputManager< ScalarType > > &	printer,
		const Teuchos::RCP< StatusTest< ScalarType, MV, OP, DM > > &	tester,
		Teuchos::ParameterList &	params
	)

RCGIter constructor with linear problem, solver utilities, and parameter list of solver options.

This constructor takes pointers required by the linear solver, in addition to a parameter list of options for the linear solver. These options include the following:

"Num Blocks" - an int specifying the maximum number of blocks allocated for the solver basis. Default: 25
"Restart Timers" = a bool specifying whether the timers should be restarted each time iterate() is called. Default: false

Definition at line 324 of file BelosRCGIter.hpp.

◆ ~RCGIter()

template<class ScalarType , class MV , class OP , class DM >

virtual Belos::RCGIter< ScalarType, MV, OP, DM >::~RCGIter ( )

inlinevirtual

Destructor.

Definition at line 139 of file BelosRCGIter.hpp.

Member Function Documentation

◆ iterate()

template<class ScalarType , class MV , class OP , class DM >

void Belos::RCGIter< ScalarType, MV, OP, DM >::iterate ( )

virtual

This method performs RCG iterations until the status test indicates the need to stop or an error occurs (in which case, an std::exception is thrown).

iterate() will first determine whether the solver is initialized; if not, it will call initialize() using default arguments. After initialization, the solver performs RCG iterations until the status test evaluates as Passed, at which point the method returns to the caller.

The status test is queried at the beginning of the iteration.

Implements Belos::Iteration< ScalarType, MV, OP, DM >.

Definition at line 454 of file BelosRCGIter.hpp.

◆ initialize() [1/2]

template<class ScalarType , class MV , class OP , class DM >

void Belos::RCGIter< ScalarType, MV, OP, DM >::initialize ( RCGIterState< ScalarType, MV, DM > & newstate )

Initialize the solver to an iterate, providing a complete state.

The RCGIter contains a certain amount of state, consisting of the current residual, preconditioned residual, and decent direction.

initialize() gives the user the opportunity to manually set these, although only the current unpreconditioned residual is required.

Postcondition: isInitialized() == true (see post-conditions of isInitialize())

Note: For any pointer in newstate which directly points to the multivectors in the solver, the data is not copied.

Definition at line 369 of file BelosRCGIter.hpp.

◆ initialize() [2/2]

template<class ScalarType , class MV , class OP , class DM >

void Belos::RCGIter< ScalarType, MV, OP, DM >::initialize ( )

inlinevirtual

Initialize the solver with the initial vectors from the linear problem or random data.

Implements Belos::Iteration< ScalarType, MV, OP, DM >.

Definition at line 179 of file BelosRCGIter.hpp.

◆ getNumIters()

template<class ScalarType , class MV , class OP , class DM >

int Belos::RCGIter< ScalarType, MV, OP, DM >::getNumIters ( ) const

inlinevirtual

Get the current iteration count.

Implements Belos::Iteration< ScalarType, MV, OP, DM >.

Definition at line 191 of file BelosRCGIter.hpp.

◆ resetNumIters()

template<class ScalarType , class MV , class OP , class DM >

void Belos::RCGIter< ScalarType, MV, OP, DM >::resetNumIters ( int iter = 0 )

inlinevirtual

Reset the iteration count.

Implements Belos::Iteration< ScalarType, MV, OP, DM >.

Definition at line 194 of file BelosRCGIter.hpp.

◆ getNativeResiduals()

template<class ScalarType , class MV , class OP , class DM >

Teuchos::RCP< const MV > Belos::RCGIter< ScalarType, MV, OP, DM >::getNativeResiduals ( std::vector< MagnitudeType > * ) const

inline

Get the norms of the residuals native to the solver.

Returns: A std::vector of length blockSize containing the native residuals.

Definition at line 198 of file BelosRCGIter.hpp.

◆ getCurrentUpdate()

template<class ScalarType , class MV , class OP , class DM >

Teuchos::RCP< MV > Belos::RCGIter< ScalarType, MV, OP, DM >::getCurrentUpdate ( ) const

inlinevirtual

Get the current update to the linear system.

Note: Some solvers, like GMRES, do not compute updates to the solution every iteration. This method forces its computation. Other solvers, like CG and RCG update the solution each iteration, so this method will return a zero std::vector indicating that the linear problem contains the current solution.

Implements Belos::Iteration< ScalarType, MV, OP, DM >.

Definition at line 206 of file BelosRCGIter.hpp.