The GMRES polynomial can be created in conjunction with any standard preconditioner. More...

#include <BelosGmresPolySolMgr.hpp>

Inheritance diagram for Belos::GmresPolySolMgr< ScalarType, MV, OP >:

Public Member Functions
Constructors/Destructor
	GmresPolySolMgr ()
	Empty constructor for GmresPolySolMgr. This constructor takes no arguments and sets the default values for the solver. The linear problem must be passed in using setProblem() before solve() is called on this object. The solver values can be changed using setParameters(). More...

	GmresPolySolMgr (const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > &problem, const Teuchos::RCP< Teuchos::ParameterList > &pl)
	Basic constructor for GmresPolySolMgr. More...

virtual	~GmresPolySolMgr ()
	Destructor. More...

Teuchos::RCP< SolverManager < ScalarType, MV, OP > >	clone () const override
	clone for Inverted Injection (DII) More...

Accessor methods
const LinearProblem < ScalarType, MV, OP > &	getProblem () const override
	Get current linear problem being solved for in this object. More...

Teuchos::RCP< const Teuchos::ParameterList >	getValidParameters () const override
	Get a parameter list containing the valid parameters for this object. More...

Teuchos::RCP< const Teuchos::ParameterList >	getCurrentParameters () const override
	Get a parameter list containing the current parameters for this object. More...

MagnitudeType	achievedTol () const override
	Tolerance achieved by the last `solve()` invocation. More...

Teuchos::Array< Teuchos::RCP < Teuchos::Time > >	getTimers () const
	Return the timers for this object. More...

int	getNumIters () const override
	Get the iteration count for the most recent call to `solve()`. More...

bool	isLOADetected () const override
	Return whether a loss of accuracy was detected by this solver during the most current solve. More...

Set methods
void	setProblem (const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > &problem) override
	Set the linear problem that needs to be solved. More...

void	setParameters (const Teuchos::RCP< Teuchos::ParameterList > &params) override
	Set the parameters the solver manager should use to solve the linear problem. More...

Reset methods
void	reset (const ResetType type) override
	Reset the solver. More...

Solver application methods
ReturnType	solve () override
	This method performs possibly repeated calls to the underlying linear solver's iterate() routine until the problem has been solved (as decided by the solver manager) or the solver manager decides to quit. More...

Overridden from Teuchos::Describable
std::string	description () const override
	Method to return description of the hybrid block GMRES solver manager. More...

Public Member Functions inherited from Belos::SolverManager< ScalarType, MV, OP >
	SolverManager ()
	Empty constructor. More...

virtual	~SolverManager ()
	Destructor. More...

virtual void	setUserConvStatusTest (const Teuchos::RCP< StatusTest< ScalarType, MV, OP > > &, const typename StatusTestCombo< ScalarType, MV, OP >::ComboType &=StatusTestCombo< ScalarType, MV, OP >::SEQ)
	Set user-defined convergence status test. More...

virtual void	setDebugStatusTest (const Teuchos::RCP< StatusTest< ScalarType, MV, OP > > &)
	Set user-defined debug status test. More...

Public Member Functions inherited from Teuchos::Describable
virtual void	describe (FancyOStream &out, const EVerbosityLevel verbLevel=verbLevel_default) const

void	describe (std::ostream &out, const EVerbosityLevel verbLevel=verbLevel_default) const

virtual	~Describable ()

	LabeledObject ()

virtual	~LabeledObject ()

virtual void	setObjectLabel (const std::string &objectLabel)

virtual std::string	getObjectLabel () const

DescribableStreamManipulatorState	describe (const Describable &describable, const EVerbosityLevel verbLevel=Describable::verbLevel_default)

std::ostream &	operator<< (std::ostream &os, const DescribableStreamManipulatorState &d)

Additional Inherited Members
Static Public Attributes inherited from Teuchos::Describable
static const EVerbosityLevel	verbLevel_default

Detailed Description

template<class ScalarType, class MV, class OP>
class Belos::GmresPolySolMgr< ScalarType, MV, OP >

The GMRES polynomial can be created in conjunction with any standard preconditioner.

Hybrid block GMRES iterative linear solver.

Simply pass the preconditioner to the LinearProblem before calling the GmresPolySolMgr and your preconditioner will be combined with the polynomial automatically.

Here is a list of all the parameters that this solver accepts:

"Polynomial Type" (std::string): The desired polynomial type: Roots, Arnoldi, or Gmres. Default: "Roots"
"Polynomial Tolerance" (MagnitudeType): The level that residual norms must reach to decide convergence. Default: 1e-8.
"Maximum Degree" (int): Requested maximum degree for the polynomial. The preconditioned problem Ap(A) will have this degree, while the polynomial p(A) will have degree deg-1. Default: 25
"Random RHS" (bool): to generate the polynomial using a random vector. Default: true
"Add Roots" (bool): to add roots to the polynomial as needed for stability. Default: true
"Damp Poly" (bool): to damp polynomial. Default: false
"Orthogonalization" (std::string): The desired orthogonalization method to create polynomial. Default: "ICGS".
"Verbosity" (Belos::MsgType): A sum of Belos::MsgType values specifying what kinds of messages to print. Default: Belos::Errors.
"Outer Solver" (std::string): Name of the outer solver in Belos solver factory.
"Outer Solver Params" (Teuchos::parameterList): List of parameters for the outer solver
"Timer Label" (std::string): Label for timers with polynomial solve.

This solver manager provides three different implementations of the same polynomial preconditioner. The polynomial is the minimum residual polynomial from GMRES. The "Roots" version is default. It is the only implementation which provides the option of added roots for stability. These added roots can allow for high-degree polynomials. The "Arnoldi" version typically gives similar results to the "Roots" version but is slightly more expensive to apply. Both of these polynomials can be "damped", which is sometimes useful for indefinite or other ill-conditioned problems. The "Gmres" version is based on a power-basis implementation and is only stable for well-conditioned problems and low-degree polynomials. For more information on the implementation and formulas, see the following references: "Roots" version: https://arxiv.org/abs/1806.08020 (Includes explanation of root-adding and damping.) "Arnoldi" version: https://scholarship.rice.edu/handle/1911/17630 "Gmres" version: https://epubs.siam.org/doi/pdf/10.1137/140968276

Like all Belos solvers, parameters have relative or "delta" semantics. This means the following:

Any parameter that was never set has its default value
Any parameter not explicitly set in the input ParameterList retains its current value

Author: Heidi Thornquist and Jennifer Loe

The GMRES polynomial solver manager can perform two types of linear solves. First the solver runs block GMRES, storing the resulting coefficients (or roots), which can be used to form a matrix polynomial. It then can reuse this polynomial as either a surrogate operator, or as a preconditioner for an outer solver. By applying the GMRES polynomial as an operator or preconditioner, one avoids the cost of the inner products and norms in GMRES, thus reducing communication costs.

Examples:: epetra/example/BlockGmres/BlockGmresPolyEpetraExFile.cpp.

Definition at line 122 of file BelosGmresPolySolMgr.hpp.

Constructor & Destructor Documentation

template<class ScalarType , class MV , class OP >

Belos::GmresPolySolMgr< ScalarType, MV, OP >::GmresPolySolMgr ( )

Empty constructor for GmresPolySolMgr. This constructor takes no arguments and sets the default values for the solver. The linear problem must be passed in using setProblem() before solve() is called on this object. The solver values can be changed using setParameters().

Definition at line 346 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

Belos::GmresPolySolMgr< ScalarType, MV, OP >::GmresPolySolMgr	(	const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > &	problem,
		const Teuchos::RCP< Teuchos::ParameterList > &	pl
	)

Basic constructor for GmresPolySolMgr.

This constructor accepts the LinearProblem to be solved in addition to a parameter list of options for the solver manager. These options include the following:

"Polynomial Type" -a std::string specifying the type of polynomial: Roots, Arnoldi, or Gmres. Default: "Roots"
"Maximum Degree" - a int specifying the maximum degree of the polynomial. Default: 25
"Random RHS" - a bool indicates whether to generate polynomial using a random vector. Default: true
"Add Roots" - a bool to add roots to the polynomial as needed for stability. Default: true
"Damp Poly" - a bool to damp polynomial. Default: false
"Orthogonalization" - a std::string specifying the desired orthogonalization to create the polynomial: DGKS, ICGS, and IMGS. Default: "ICGS"
"Verbosity" - a sum of MsgType specifying the verbosity. Default: Belos::Errors
"Polynomial Tolerance" - a MagnitudeType specifying the polynomial tolerance (sometimes) used to generate polynomial. Default: 1e-8
"Outer Solver" -a std::string specifying name of outer solver in Belos solver factory. Default: ""
"Outer Solver Params" -a Teuchos::ParameterList giving parameters for the outer solver.
"Timer Label" -a std::string specifying the label on polynomial solve timers.

Definition at line 369 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

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

inlinevirtual

Destructor.

Definition at line 165 of file BelosGmresPolySolMgr.hpp.

Member Function Documentation

template<class ScalarType , class MV , class OP >

Teuchos::RCP<SolverManager<ScalarType, MV, OP> > Belos::GmresPolySolMgr< ScalarType, MV, OP >::clone ( ) const

inlineoverridevirtual

clone for Inverted Injection (DII)

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 168 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

const LinearProblem<ScalarType,MV,OP>& Belos::GmresPolySolMgr< ScalarType, MV, OP >::getProblem ( ) const

inlineoverridevirtual

Get current linear problem being solved for in this object.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 178 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

Teuchos::RCP< const Teuchos::ParameterList > Belos::GmresPolySolMgr< ScalarType, MV, OP >::getValidParameters ( ) const

overridevirtual

Get a parameter list containing the valid parameters for this object.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 405 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

Teuchos::RCP<const Teuchos::ParameterList> Belos::GmresPolySolMgr< ScalarType, MV, OP >::getCurrentParameters ( ) const

inlineoverridevirtual

Get a parameter list containing the current parameters for this object.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 188 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

MagnitudeType Belos::GmresPolySolMgr< ScalarType, MV, OP >::achievedTol ( ) const

inlineoverridevirtual

Tolerance achieved by the last solve() invocation.

This is the maximum over all right-hand sides' achieved convergence tolerances, and is set whether or not the solve actually managed to achieve the desired convergence tolerance.

Warning: This solver manager may be use as either a polynomial preconditioned iterative method or a polynomial preconditioner. In the later case, where a static polynomial is being applied through each call to solve(), there is not an outer solve that can provide the achieved tolerance.; This result may not be meaningful if there was a loss of accuracy during the outer solve. You should first call isLOADetected() to check for a loss of accuracy during the last solve.

Reimplemented from Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 206 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

Teuchos::Array<Teuchos::RCP<Teuchos::Time> > Belos::GmresPolySolMgr< ScalarType, MV, OP >::getTimers ( ) const

inline

Return the timers for this object.

The timers are ordered as follows:

time spent in solve() routine

Definition at line 215 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

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

inlineoverridevirtual

Get the iteration count for the most recent call to solve().

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 220 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

bool Belos::GmresPolySolMgr< ScalarType, MV, OP >::isLOADetected ( ) const

inlineoverridevirtual

Return whether a loss of accuracy was detected by this solver during the most current solve.

Note: This flag will be reset the next time solve() is called.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 227 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

void Belos::GmresPolySolMgr< ScalarType, MV, OP >::setProblem ( const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > & problem )

inlineoverridevirtual

Set the linear problem that needs to be solved.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 235 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

void Belos::GmresPolySolMgr< ScalarType, MV, OP >::setParameters ( const Teuchos::RCP< Teuchos::ParameterList > & params )

overridevirtual

Set the parameters the solver manager should use to solve the linear problem.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 446 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

void Belos::GmresPolySolMgr< ScalarType, MV, OP >::reset ( const ResetType type )

inlineoverridevirtual

Reset the solver.

Parameters

type	[in] How to reset the solver.

If type includes Belos::Problem, then reset the solver's state. This clears out the stored coefficients, so that the next call to solve() actually computes a full block GMRES solve, instead of just reusing the coefficients from the first solve.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 252 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

ReturnType Belos::GmresPolySolMgr< ScalarType, MV, OP >::solve ( )

overridevirtual

This method performs possibly repeated calls to the underlying linear solver's iterate() routine until the problem has been solved (as decided by the solver manager) or the solver manager decides to quit.

This method calls BlockGmresIter::iterate(), which will return either because a specially constructed status test evaluates to Passed or an std::exception is thrown.

A return from BlockGmresIter::iterate() signifies one of the following scenarios:

the maximum number of restarts has been exceeded. In this scenario, the current solutions to the linear system will be placed in the linear problem and return Unconverged.
global convergence has been met. In this case, the current solutions to the linear system will be placed in the linear problem and the solver manager will return Converged

Returns

ReturnType specifying:

Converged: the linear problem was solved to the specification required by the solver manager.
Unconverged: the linear problem was not solved to the specification desired by the solver manager.

Implements Belos::SolverManager< ScalarType, MV, OP >.

Definition at line 600 of file BelosGmresPolySolMgr.hpp.

template<class ScalarType , class MV , class OP >

std::string Belos::GmresPolySolMgr< ScalarType, MV, OP >::description ( ) const

overridevirtual

Method to return description of the hybrid block GMRES solver manager.

Reimplemented from Teuchos::Describable.

Definition at line 710 of file BelosGmresPolySolMgr.hpp.

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

BelosGmresPolySolMgr.hpp

Public Member Functions

Additional Inherited Members

Detailed Description

template<class ScalarType, class MV, class OP> class Belos::GmresPolySolMgr< ScalarType, MV, OP >

Constructor & Destructor Documentation

Member Function Documentation

template<class ScalarType, class MV, class OP>
class Belos::GmresPolySolMgr< ScalarType, MV, OP >