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Belos::GCRODRSolMgr< ScalarType, MV, OP > Class Template Reference

Implementation of the GCRODR (Recycling GMRES) iterative linear solver. More...

#include <BelosGCRODRSolMgr.hpp>

Inheritance diagram for Belos::GCRODRSolMgr< ScalarType, MV, OP >:
Inheritance graph
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List of all members.

Public Member Functions

Constructors/Destructor
 GCRODRSolMgr ()
 Empty constructor for GCRODRSolMgr. 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().
 GCRODRSolMgr (const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > &problem, const Teuchos::RCP< Teuchos::ParameterList > &pl)
 Basic constructor for GCRODRSolMgr.
virtual ~GCRODRSolMgr ()
 Destructor.
Accessor methods
const LinearProblem
< ScalarType, MV, OP > & 		getProblem () const
 Get current linear problem being solved for in this object.
Teuchos::RCP< const
Teuchos::ParameterList > 		getValidParameters () const
 Get a parameter list containing the valid parameters for this object.
Teuchos::RCP< const
Teuchos::ParameterList > 		getCurrentParameters () const
 Get a parameter list containing the current parameters for this object.
Teuchos::Array< Teuchos::RCP
< Teuchos::Time > > 		getTimers () const
 Return the timers for this object.
MagnitudeType achievedTol () const
 Tolerance achieved by the last solve() invocation.
int getNumIters () const
 Get the iteration count for the most recent call to solve().
bool isLOADetected () const
 Return whether a loss of accuracy was detected by this solver during the most current solve.
Set methods
void setProblem (const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > &problem)
 Set the linear problem that needs to be solved.
void setParameters (const Teuchos::RCP< Teuchos::ParameterList > &params)
 Set the parameters the solver manager should use to solve the linear problem.
Reset methods
void reset (const ResetType type)
 Performs a reset of the solver manager specified by the ResetType. This informs the solver manager that the solver should prepare for the next call to solve by resetting certain elements of the iterative solver strategy.
Solver application methods
ReturnType solve ()
 Attempt to solve the linear system.
Implementation of Teuchos::Describable
std::string description () const
 Return a one-line description of this object.

Detailed Description

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

Implementation of the GCRODR (Recycling GMRES) iterative linear solver.

Author:
Michael Parks and Heidi Thornquist
Template Parameters:
ScalarTypeThe type of entries in the right-hand side vector(s) $b$ and solution vector(s) $x$.
MVThe multivector type; the type of the solution vector(s) and right-hand side vector(s).
OPThe type of the matrix $A$ (and any preconditioner, if one is provided).

Summary

This class implements the GCRODR (Recycling GMRES) iterative linear solver. This solver is suited for solving sequences of related linear systems $A_i x_i = b_i$. For details, please refer to the following paper:

Michael L. Parks, Eric de Sturler, Greg Mackey, Duane Johnson, and Spandan Maiti. "Recycling Krylov Subspaces for Sequences of Linear Systems," SIAM Journal on Scientific Computing, 28(5), pp. 1651-1674, 2006.

Examples:
GCRODR/GCRODREpetraExFile.cpp, and GCRODR/PrecGCRODREpetraExFile.cpp.

Definition at line 153 of file BelosGCRODRSolMgr.hpp.

Constructor & Destructor Documentation

template<class ScalarType , class MV , class OP >
Belos::GCRODRSolMgr< ScalarType, MV, OP >::GCRODRSolMgr ( )

Empty constructor for GCRODRSolMgr. 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 532 of file BelosGCRODRSolMgr.hpp.

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

Basic constructor for GCRODRSolMgr.

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

  • "Num Blocks": an int specifying the number of blocks allocated for the Krylov basis. Default: 50.
  • "Num Recycled Blocks": an int specifying the number of blocks allocated for the Krylov basis. Default: 5.
  • "Maximum Iterations": an int specifying the maximum number of iterations the underlying solver is allowed to perform. Default: 5000.
  • "Maximum Restarts": an int specifying the maximum number of restarts the underlying solver is allowed to perform. Default: 100.
  • "Orthogonalization": an std::string specifying the desired orthogonalization. Currently supported values: "DGKS", "ICGS", "IMGS", and "TSQR" (if Belos was built with TSQR support). Default: "DGKS".
  • "Orthogonalization Parameters": a sublist of parameters specific to the type of orthogonalization used. Defaults are set automatically.
  • "Verbosity": a sum of MsgType specifying the verbosity. Default: Belos::Errors.
  • "Output Style": a OutputType specifying the style of output. Default: Belos::General.
  • "Convergence Tolerance": a MagnitudeType specifying the level that residual norms must reach to decide convergence. Default: 1e-8.

Other supported options:

  • "Output Frequency": an int specifying how often (in terms of number of iterations) convergence information should be output to the output stream. Default: -1 (means never output convergence information).
  • "Output Stream": a reference-counted pointer to the output stream where all solver output is sent. Default stream is std::cout (stdout, in C terms). For stderr, supply Teuchos::rcp(&std::cerr, false).
  • "Implicit Residual Scaling": the type of scaling used in the implicit residual convergence test. Default: "Norm of Preconditioned Initial Residual".
  • "Explicit Residual Scaling": the type of scaling used in the explicit residual convergence test. Default: "Norm of Initial Residual".
  • "Timer Label": the string to use as a prefix for the timer labels. Default: "Belos"
  • "Orthogonalization Constant": a MagnitudeType corresponding to the "depTol" parameter of DGKS orthogonalization. Ignored unless DGKS orthogonalization is used. DGKS decides the default value.

Definition at line 543 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
virtual Belos::GCRODRSolMgr< ScalarType, MV, OP >::~GCRODRSolMgr ( ) [inline, virtual]

Destructor.

Definition at line 232 of file BelosGCRODRSolMgr.hpp.

Member Function Documentation

template<class ScalarType , class MV , class OP >
const LinearProblem<ScalarType,MV,OP>& Belos::GCRODRSolMgr< ScalarType, MV, OP >::getProblem ( ) const [inline, virtual]

Get current linear problem being solved for in this object.

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

Definition at line 240 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
Teuchos::RCP< const Teuchos::ParameterList > Belos::GCRODRSolMgr< ScalarType, MV, OP >::getValidParameters ( ) const [virtual]

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

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

Definition at line 1104 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
Teuchos::RCP<const Teuchos::ParameterList> Belos::GCRODRSolMgr< ScalarType, MV, OP >::getCurrentParameters ( ) const [inline, virtual]

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

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

Definition at line 250 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
Teuchos::Array<Teuchos::RCP<Teuchos::Time> > Belos::GCRODRSolMgr< ScalarType, MV, OP >::getTimers ( ) const [inline]

Return the timers for this object.

The timers are ordered as follows:

Definition at line 259 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
MagnitudeType Belos::GCRODRSolMgr< ScalarType, MV, OP >::achievedTol ( ) const [inline, virtual]

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.

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

Definition at line 268 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
int Belos::GCRODRSolMgr< ScalarType, MV, OP >::getNumIters ( ) const [inline, virtual]

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

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

Definition at line 273 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
bool Belos::GCRODRSolMgr< ScalarType, MV, OP >::isLOADetected ( ) const [inline, virtual]

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

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

Definition at line 279 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
void Belos::GCRODRSolMgr< ScalarType, MV, OP >::setProblem ( const Teuchos::RCP< LinearProblem< ScalarType, MV, OP > > &  problem) [inline]

Set the linear problem that needs to be solved.

Definition at line 287 of file BelosGCRODRSolMgr.hpp.

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

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

Definition at line 606 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
void Belos::GCRODRSolMgr< ScalarType, MV, OP >::reset ( const ResetType  type) [inline, virtual]

Performs a reset of the solver manager specified by the ResetType. This informs the solver manager that the solver should prepare for the next call to solve by resetting certain elements of the iterative solver strategy.

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

Definition at line 302 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
ReturnType Belos::GCRODRSolMgr< ScalarType, MV, OP >::solve ( ) [virtual]

Attempt to solve the linear system.

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 GCRODRIter::iterate(), which will return either because a specially constructed status test evaluates to Passed or an exception is thrown. A return from GCRODRIter::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 1303 of file BelosGCRODRSolMgr.hpp.

template<class ScalarType , class MV , class OP >
std::string Belos::GCRODRSolMgr< ScalarType, MV, OP >::description ( ) const [virtual]

Return a one-line description of this object.

Reimplemented from Teuchos::Describable.

Definition at line 2374 of file BelosGCRODRSolMgr.hpp.

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