Iterative eigenvalue algorithms based on power iteration. More...

#include <dune/istl/eigenvalue/poweriteration.hh>

Public Types
typedef BlockVector::field_type	Real
	Type of underlying field.

typedef OperatorSum	IterationOperator
	Type of iteration operator (m_ - mu_*I)

Public Member Functions
	PowerIteration_Algorithms (const BCRSMatrix &m, const unsigned int nIterationsMax=1000, const unsigned int verbosity_level=0)
	Construct from required parameters. More...

	PowerIteration_Algorithms (const PowerIteration_Algorithms &)=delete

PowerIteration_Algorithms &	operator= (const PowerIteration_Algorithms &)=delete

void	applyPowerIteration (const Real &epsilon, BlockVector &x, Real &lambda) const
	Perform the power iteration algorithm to compute an approximation lambda of the dominant (i.e. largest magnitude) eigenvalue and the corresponding approximation x of an associated eigenvector. More...

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>
void	applyInverseIteration (const Real &epsilon, ISTLLinearSolver &solver, BlockVector &x, Real &lambda) const
	Perform the inverse iteration algorithm to compute an approximation lambda of the least dominant (i.e. smallest magnitude) eigenvalue and the corresponding approximation x of an associated eigenvector. More...

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>
void	applyInverseIteration (const Real &gamma, const Real &epsilon, ISTLLinearSolver &solver, BlockVector &x, Real &lambda) const
	Perform the inverse iteration with shift algorithm to compute an approximation lambda of the eigenvalue closest to a given shift and the corresponding approximation x of an associated eigenvector. More...

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>
void	applyRayleighQuotientIteration (const Real &epsilon, ISTLLinearSolver &solver, BlockVector &x, Real &lambda) const
	Perform the Rayleigh quotient iteration algorithm to compute an approximation lambda of an eigenvalue and the corresponding approximation x of an associated eigenvector. More...

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>
void	applyTLIMEIteration (const Real &gamma, const Real &eta, const Real &epsilon, ISTLLinearSolver &solver, const Real &delta, const std::size_t &m, bool &extrnl, BlockVector &x, Real &lambda) const
	Perform the "two-level iterative method for eigenvalue calculations (TLIME)" iteration algorithm presented in [Szyld, 1988] to compute an approximation lambda of an eigenvalue and the corresponding approximation x of an associated eigenvector. More...

IterationOperator &	getIterationOperator ()
	Return the iteration operator (m_ - mu_*I). More...

const BCRSMatrix &	getIterationMatrix () const
	Return the iteration matrix (m_ - mu_*I), provided on demand when needed (e.g. for direct solvers or preconditioning). More...

unsigned int	getIterationCount () const
	Return the number of iterations in last application of an algorithm.

Protected Member Functions
template<typename ISTLLinearSolver >
void	updateShiftMu (const Real &mu, ISTLLinearSolver &solver) const
	Update shift mu_, i.e. update iteration operator/matrix (m_ - mu_*I). More...

Detailed Description

template<typename BCRSMatrix, typename BlockVector>
class Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >

Iterative eigenvalue algorithms based on power iteration.

Given a square matrix whose eigenvalues shall be considered, this class template provides methods for performing the power iteration algorithm, the inverse iteration algorithm, the inverse iteration with shift algorithm, the Rayleigh quotient iteration algorithm and the TLIME iteration algorithm.

Note: Note that all algorithms except the power iteration algorithm require matrix inversion via a linear solver. When using an iterative linear solver, the algorithms become inexact "inner-outer" iterative methods. It is known that the number of inner solver iterations can increase steadily as the outer eigenvalue iteration proceeds. In this case, you should consider using a "tuned preconditioner", see e.g. [Freitag and Spence, 2008].; In the current implementation, preconditioners like Dune::SeqILUn which are based on matrix decomposition act on the initial iteration matrix in each iteration, even for methods like the Rayleigh quotient algorithm in which the iteration matrix (m_ - mu_*I) may change in each iteration. This is due to the fact that those preconditioners currently don't support to be notified about a change of the matrix object.

Todo:: The current implementation is limited to DUNE-ISTL BCRSMatrix types with blocklevel 2. An extension to blocklevel >= 2 might be provided in a future version.

Template Parameters

BCRSMatrix	Type of a DUNE-ISTL BCRSMatrix whose eigenvalues shall be considered; is assumed to have blocklevel 2 with square blocks.
BlockVector	Type of the associated vectors; compatible with the rows of a BCRSMatrix object and its columns.

Author: Sebastian Westerheide.

Constructor & Destructor Documentation

◆ PowerIteration_Algorithms() [1/2]

template<typename BCRSMatrix , typename BlockVector >

Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::PowerIteration_Algorithms	(	const BCRSMatrix &	m,
		const unsigned int	nIterationsMax = `1000`,
		const unsigned int	verbosity_level = `0`
	)

inline

Construct from required parameters.

Parameters

[in]	m	The square DUNE-ISTL BCRSMatrix whose eigenvalues shall be considered.
[in]	nIterationsMax	The maximum number of iterations allowed.
[in]	verbosity_level	Verbosity setting; >= 1: algorithms print a preamble and the final result, >= 2: algorithms print information on each iteration, >= 3: the final result output includes the approximated eigenvector.

References DUNE_THROW, Dune::BCRSMatrix< B, A >::M(), and Dune::BCRSMatrix< B, A >::N().

◆ PowerIteration_Algorithms() [2/2]

template<typename BCRSMatrix , typename BlockVector >

Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::PowerIteration_Algorithms ( const PowerIteration_Algorithms< BCRSMatrix, BlockVector > & )

delete

disallow copying (default copy constructor does a shallow copy, if copying was required a deep copy would have to be implemented due to member variables which hold a dynamically allocated object)

Member Function Documentation

◆ applyInverseIteration() [1/2]

template<typename BCRSMatrix , typename BlockVector >

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>

void Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::applyInverseIteration	(	const Real &	epsilon,
		ISTLLinearSolver &	solver,
		BlockVector &	x,
		Real &	lambda
	)		const

inline

Perform the inverse iteration algorithm to compute an approximation lambda of the least dominant (i.e. smallest magnitude) eigenvalue and the corresponding approximation x of an associated eigenvector.

Template Parameters

ISTLLinearSolver	Type of a DUNE-ISTL InverseOperator which shall be used as a linear solver.
avoidLinSolverCrime	The less accurate the linear solver is, the more corrupted gets the implemented computation of lambda and its associated residual. Setting this mode can help increasing their accuracy at the cost of a bit of efficiency which is beneficial e.g. when using a very inexact linear solver. Defaults to false.

Parameters

[in]	epsilon	The target residual norm.
[in]	solver	The DUNE-ISTL InverseOperator which shall be used as a linear solver; is assumed to be constructed using the linear operator returned by getIterationOperator() (resp. matrix returned by getIterationMatrix()).
[out]	lambda	The approximated least dominant eigenvalue.
[in,out]	x	The associated approximated eigenvector; shall be initialized with an estimate for an eigenvector associated with the eigenvalue which shall be approximated.

◆ applyInverseIteration() [2/2]

template<typename BCRSMatrix , typename BlockVector >

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>

void Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::applyInverseIteration	(	const Real &	gamma,
		const Real &	epsilon,
		ISTLLinearSolver &	solver,
		BlockVector &	x,
		Real &	lambda
	)		const

inline

Perform the inverse iteration with shift algorithm to compute an approximation lambda of the eigenvalue closest to a given shift and the corresponding approximation x of an associated eigenvector.

Template Parameters

ISTLLinearSolver	Type of a DUNE-ISTL InverseOperator which shall be used as a linear solver.
avoidLinSolverCrime	The less accurate the linear solver is, the more corrupted gets the implemented computation of lambda and its associated residual. Setting this mode can help increasing their accuracy at the cost of a bit of efficiency which is beneficial e.g. when using a very inexact linear solver. Defaults to false.

Parameters

[in]	gamma	The shift.
[in]	epsilon	The target residual norm.
[in]	solver	The DUNE-ISTL InverseOperator which shall be used as a linear solver; is assumed to be constructed using the linear operator returned by getIterationOperator() (resp. matrix returned by getIterationMatrix()).
[out]	lambda	The approximated eigenvalue closest to gamma.
[in,out]	x	The associated approximated eigenvector; shall be initialized with an estimate for an eigenvector associated with the eigenvalue which shall be approximated.

◆ applyPowerIteration()

template<typename BCRSMatrix , typename BlockVector >

void Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::applyPowerIteration	(	const Real &	epsilon,
		BlockVector &	x,
		Real &	lambda
	)		const

inline

Perform the power iteration algorithm to compute an approximation lambda of the dominant (i.e. largest magnitude) eigenvalue and the corresponding approximation x of an associated eigenvector.

Parameters

[in]	epsilon	The target residual norm.
[out]	lambda	The approximated dominant eigenvalue.
[in,out]	x	The associated approximated eigenvector; shall be initialized with an estimate for an eigenvector associated with the eigenvalue which shall be approximated.

◆ applyRayleighQuotientIteration()

template<typename BCRSMatrix , typename BlockVector >

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>

void Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::applyRayleighQuotientIteration	(	const Real &	epsilon,
		ISTLLinearSolver &	solver,
		BlockVector &	x,
		Real &	lambda
	)		const

inline

Perform the Rayleigh quotient iteration algorithm to compute an approximation lambda of an eigenvalue and the corresponding approximation x of an associated eigenvector.

Template Parameters

ISTLLinearSolver	Type of a DUNE-ISTL InverseOperator which shall be used as a linear solver.
avoidLinSolverCrime	The less accurate the linear solver is, the more corrupted gets the implemented computation of lambda and its associated residual. Setting this mode can help increasing their accuracy at the cost of a bit of efficiency which is beneficial e.g. when using a very inexact linear solver. Defaults to false.

Parameters

[in]	epsilon	The target residual norm.
[in]	solver	The DUNE-ISTL InverseOperator which shall be used as a linear solver; is assumed to be constructed using the linear operator returned by getIterationOperator() (resp. matrix returned by getIterationMatrix()).
[in,out]	lambda	The approximated eigenvalue; shall be initialized with an estimate for the eigenvalue which shall be approximated.
[in,out]	x	The associated approximated eigenvector; shall be initialized with an estimate for an eigenvector associated with the eigenvalue which shall be approximated.

◆ applyTLIMEIteration()

template<typename BCRSMatrix , typename BlockVector >

template<typename ISTLLinearSolver , bool avoidLinSolverCrime = false>

void Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::applyTLIMEIteration	(	const Real &	gamma,
		const Real &	eta,
		const Real &	epsilon,
		ISTLLinearSolver &	solver,
		const Real &	delta,
		const std::size_t &	m,
		bool &	extrnl,
		BlockVector &	x,
		Real &	lambda
	)		const

inline

Perform the "two-level iterative method for eigenvalue calculations (TLIME)" iteration algorithm presented in [Szyld, 1988] to compute an approximation lambda of an eigenvalue and the corresponding approximation x of an associated eigenvector.

The algorithm combines the inverse iteration with shift and the Rayleigh quotient iteration in order to compute an eigenvalue in a given interval J = (gamma - eta, gamma + eta). It guarantees that if an eigenvalue exists in J, the method will converge to an eigenvalue in J, while exploiting the cubic convergence of the Rayleigh quotient iteration, but without its drawback that - depending on the initial vector - it can converge to an arbitrary eigenvalue of the matrix. When J is free of eigenvalues, the method will determine this fact and converge linearly to the eigenvalue closest to J.

Template Parameters

ISTLLinearSolver	Type of a DUNE-ISTL InverseOperator which shall be used as a linear solver.
avoidLinSolverCrime	The less accurate the linear solver is, the more corrupted gets the implemented computation of lambda and its associated residual. Setting this mode can help increasing their accuracy at the cost of a bit of efficiency which is beneficial e.g. when using a very inexact linear solver. Defaults to false.

Parameters

[in]	gamma	An estimate for the eigenvalue which shall be approximated.
[in]	eta	Radius around gamma in which the eigenvalue is expected.
[in]	epsilon	The target norm of the residual with respect to the Rayleigh quotient.
[in]	solver	The DUNE-ISTL InverseOperator which shall be used as a linear solver; is assumed to be constructed using the linear operator returned by getIterationOperator() (resp. matrix returned by getIterationMatrix()).
[in]	delta	The target relative change of the Rayleigh quotient, indicating that inverse iteration has become stationary and switching to Rayleigh quotient iteration is appropriate; is only considered if J is free of eigenvalues.
[in]	m	The minimum number of inverse iterations before switching to Rayleigh quotient iteration; is only considered if J is free of eigenvalues.
[out]	extrnl	If true, the interval J is free of eigenvalues; the approximated eigenvalue-eigenvector pair (lambda,x_s) then corresponds to the eigenvalue closest to J.
[out]	lambda	The approximated eigenvalue.
[in,out]	x	The associated approximated eigenvector; shall be initialized with an estimate for an eigenvector associated with the eigenvalue which shall be approximated.

◆ getIterationMatrix()

template<typename BCRSMatrix , typename BlockVector >

const BCRSMatrix & Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::getIterationMatrix ( ) const

inline

Return the iteration matrix (m_ - mu_*I), provided on demand when needed (e.g. for direct solvers or preconditioning).

The matrix returned by this method shall be used to create the linear solver object if it requires that the matrix is provided explicitly. For linear solvers which operate completely matrix free use getIterationOperator() instead.

Note: Calling this method creates a new DUNE-ISTL BCRSMatrix object which requires as much memory as the matrix whose eigenvalues shall be considered.

◆ getIterationOperator()

template<typename BCRSMatrix , typename BlockVector >

IterationOperator & Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::getIterationOperator ( )

inline

Return the iteration operator (m_ - mu_*I).

The linear operator returned by this method shall be used to create the linear solver object. For linear solvers or preconditioners which require that the matrix is provided explicitly use getIterationMatrix() instead/additionally.

◆ operator=()

template<typename BCRSMatrix , typename BlockVector >

PowerIteration_Algorithms & Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::operator= ( const PowerIteration_Algorithms< BCRSMatrix, BlockVector > & )

delete

disallow copying (default assignment operator does a shallow copy, if copying was required a deep copy would have to be implemented due to member variables which hold a dynamically allocated object)

◆ updateShiftMu()

template<typename BCRSMatrix , typename BlockVector >

template<typename ISTLLinearSolver >

void Dune::PowerIteration_Algorithms< BCRSMatrix, BlockVector >::updateShiftMu	(	const Real &	mu,
		ISTLLinearSolver &	solver
	)		const

inlineprotected

Update shift mu_, i.e. update iteration operator/matrix (m_ - mu_*I).

Note: Does nothing if new shift equals the old one.

Template Parameters

ISTLLinearSolver Type of a DUNE-ISTL InverseOperator which is used as a linear solver.

Parameters

[in]	mu	The new shift.
[in]	solver	The DUNE-ISTL InverseOperator which is used as a linear solver.

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

dune/istl/eigenvalue/poweriteration.hh

DUNE Distributed and Unified Numerics Environment

Dune Core Modules (2.8.0)

Public Types

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ PowerIteration_Algorithms() [1/2]

◆ PowerIteration_Algorithms() [2/2]

Member Function Documentation

◆ applyInverseIteration() [1/2]

◆ applyInverseIteration() [2/2]

◆ applyPowerIteration()

◆ applyRayleighQuotientIteration()

◆ applyTLIMEIteration()

◆ getIterationMatrix()

◆ getIterationOperator()

◆ operator=()

◆ updateShiftMu()