Detailed Description

template<typename Number, typename MemorySpace = ::MemorySpace::Host>
struct LinearAlgebra::TpetraWrappers::PreconditionL1GaussSeidel< Number, MemorySpace >::AdditionalData

The set of additional parameters to tune the preconditioner.

Definition at line 533 of file trilinos_tpetra_precondition.h.

Public Member Functions
	AdditionalData (const double omega=1, const double eta=1.5, const bool fix_diagonal=false, const double min_diagonal=0, const int n_sweeps=1)
	Constructor.

Public Attributes
double	omega
	Relaxation damping factor.
double	eta
	Threshold parameter for diagonal correction.
bool	fix_diagonal
	Whether or not to enlarge entries below a threshold.
double	min_diagonal
	Threshold below which entries will be fixed.
int	n_sweeps
	Set how often the preconditioner should be applied during vmult() or Tvmult().

Constructor & Destructor Documentation

◆ AdditionalData()

template<typename Number, typename MemorySpace = ::MemorySpace::Host>

LinearAlgebra::TpetraWrappers::PreconditionL1GaussSeidel< Number, MemorySpace >::AdditionalData::AdditionalData	(	const double	omega = 1,
		const double	eta = 1.5,
		const bool	fix_diagonal = false,
		const double	min_diagonal = 0,
		const int	n_sweeps = 1 )

Constructor.

Set the parameters to be used in the preconditioner. The defaults yield the l1 Gauss-Seidel preconditioner specified in the original publication.

Parameters

omega	The damping factor for the relaxation.
eta	Threshold parameter for diagonal correction.
fix_diagonal	Fix small diagonal entries for the inversion?
min_diagonal	Threshold for fix_diagonal.
n_sweeps	Number of relaxation sweeps per call to vmult or Tvmult.

Member Data Documentation

◆ omega

template<typename Number, typename MemorySpace = ::MemorySpace::Host>

double LinearAlgebra::TpetraWrappers::PreconditionL1GaussSeidel< Number, MemorySpace >::AdditionalData::omega

Relaxation damping factor.

Definition at line 558 of file trilinos_tpetra_precondition.h.

◆ eta

template<typename Number, typename MemorySpace = ::MemorySpace::Host>

double LinearAlgebra::TpetraWrappers::PreconditionL1GaussSeidel< Number, MemorySpace >::AdditionalData::eta

Threshold parameter for diagonal correction.

The l1 correction for a row i will only be added if it is more than eta times larger than the original diagonal entry.

Definition at line 567 of file trilinos_tpetra_precondition.h.

◆ fix_diagonal

template<typename Number, typename MemorySpace = ::MemorySpace::Host>

bool LinearAlgebra::TpetraWrappers::PreconditionL1GaussSeidel< Number, MemorySpace >::AdditionalData::fix_diagonal

Whether or not to enlarge entries below a threshold.

If the matrix diagonal contains entries close to zero, their inversion will be close to division by zero. This can be corrected by setting this value to true. This will result in additional computational work during initialization.

Definition at line 576 of file trilinos_tpetra_precondition.h.