A parsed ILU preconditioner which uses parameter files to choose between different options. More...

#include <ilu.h>

Inheritance diagram for ParsedLAC::ILUPreconditioner:

Public Member Functions
	ILUPreconditioner (const std::string &name="", const unsigned int &ilu_fill=0, const double &ilu_atol=0.0, const double &ilu_rtol=1.0, const unsigned int &overlap=0)
	Constructor. More...

template<typename Matrix >
void	initialize_preconditioner (const Matrix &matrix)
	Initialize the preconditioner using `matrix`. More...

Public Member Functions inherited from ParameterAcceptor
	ParameterAcceptor (const std::string &section_name="")

unsigned int	get_acceptor_id () const

virtual	~ParameterAcceptor () override

virtual void	declare_parameters (ParameterHandler &prm)

virtual void	parse_parameters (ParameterHandler &prm)

std::string	get_section_name () const

std::vector< std::string >	get_section_path () const

void	add_parameter (const std::string &entry, ParameterType &parameter, const std::string &documentation="", ParameterHandler &prm_=prm, const Patterns::PatternBase &pattern=*Patterns::Tools::Convert< ParameterType >::to_pattern())

void	enter_subsection (const std::string &subsection)

void	leave_subsection ()

void	enter_my_subsection (ParameterHandler &prm)

void	leave_my_subsection (ParameterHandler &prm)

void	serialize (Archive &ar, const unsigned int version)

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

Public Member Functions inherited from Subscriptor
	Subscriptor ()

	Subscriptor (const Subscriptor &)

	Subscriptor (Subscriptor &&) noexcept

virtual	~Subscriptor ()

Subscriptor &	operator= (const Subscriptor &)

Subscriptor &	operator= (Subscriptor &&) noexcept

void	serialize (Archive &ar, const unsigned int version)

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

Public Member Functions inherited from TrilinosWrappers::PreconditionILU
void	initialize (const SparseMatrix &matrix, const AdditionalData &additional_data=AdditionalData())

void	clear ()

MPI_Comm	get_mpi_communicator () const

void	transpose ()

virtual void	vmult (MPI::Vector &dst, const MPI::Vector &src) const

virtual void	vmult (::Vector< double > &dst, const ::Vector< double > &src) const

virtual void	vmult (::LinearAlgebra::distributed::Vector< double > &dst, const ::LinearAlgebra::distributed::Vector< double > &src) const

virtual void	Tvmult (MPI::Vector &dst, const MPI::Vector &src) const

virtual void	Tvmult (::Vector< double > &dst, const ::Vector< double > &src) const

virtual void	Tvmult (::LinearAlgebra::distributed::Vector< double > &dst, const ::LinearAlgebra::distributed::Vector< double > &src) const

void	serialize (Archive &ar, const unsigned int version)

Epetra_Operator &	trilinos_operator () const

IndexSet	locally_owned_domain_indices () const

IndexSet	locally_owned_range_indices () const

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

Epetra_Operator &	trilinos_operator () const

IndexSet	locally_owned_domain_indices () const

IndexSet	locally_owned_range_indices () const

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

Public Member Functions inherited from TrilinosWrappers::PreconditionBase
	PreconditionBase ()

void	clear ()

MPI_Comm	get_mpi_communicator () const

void	transpose ()

void	serialize (Archive &ar, const unsigned int version)

Epetra_Operator &	trilinos_operator () const

IndexSet	locally_owned_domain_indices () const

IndexSet	locally_owned_range_indices () const

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

Epetra_Operator &	trilinos_operator () const

IndexSet	locally_owned_domain_indices () const

IndexSet	locally_owned_range_indices () const

void	subscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

void	unsubscribe (std::atomic< bool > *const validity, const std::string &identifier="") const

unsigned int	n_subscriptions () const

void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

Private Member Functions
void	add_parameters ()
	Declare preconditioner options. More...

Private Attributes
unsigned int	ilu_fill
	This specifies the amount of additional fill-in elements besides the original sparse matrix structure. More...

double	ilu_atol
	The amount of perturbation to add to diagonal entries. More...

double	ilu_rtol
	Scaling factor for diagonal entries. More...

unsigned int	overlap
	Overlap between processors. More...

Additional Inherited Members
Public Types inherited from TrilinosWrappers::PreconditionILU
typedef ::types::global_dof_index	size_type

Public Types inherited from TrilinosWrappers::PreconditionBase
typedef ::types::global_dof_index	size_type

Static Public Member Functions inherited from ParameterAcceptor
static void	initialize (const std::string &filename="", const std::string &output_filename="", const ParameterHandler::OutputStyle output_style_for_output_filename=ParameterHandler::Short, ParameterHandler &prm=ParameterAcceptor::prm, const ParameterHandler::OutputStyle output_style_for_filename=ParameterHandler::DefaultStyle)

static void	initialize (std::istream &input_stream, ParameterHandler &prm=ParameterAcceptor::prm)

static void	clear ()

static void	parse_all_parameters (ParameterHandler &prm=ParameterAcceptor::prm)

static void	declare_all_parameters (ParameterHandler &prm=ParameterAcceptor::prm)

static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Static Public Member Functions inherited from Subscriptor
static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Static Public Member Functions inherited from TrilinosWrappers::PreconditionILU
static ::ExceptionBase &	ExcNonMatchingMaps (std::string arg1)

static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Static Public Member Functions inherited from TrilinosWrappers::PreconditionBase
static ::ExceptionBase &	ExcNonMatchingMaps (std::string arg1)

static ::ExceptionBase &	ExcInUse (int arg1, std::string arg2, std::string arg3)

static ::ExceptionBase &	ExcNoSubscriber (std::string arg1, std::string arg2)

Public Attributes inherited from ParameterAcceptor
boost::signals2::signal< void()>	declare_parameters_call_back

boost::signals2::signal< void()>	parse_parameters_call_back

Static Public Attributes inherited from ParameterAcceptor
static ParameterHandler	prm

Protected Attributes inherited from ParameterAcceptor
const std::string	section_name

std::vector< std::string >	subsections

Protected Attributes inherited from TrilinosWrappers::PreconditionILU
Teuchos::RCP< Epetra_Operator >	preconditioner

Epetra_MpiComm	communicator

Protected Attributes inherited from TrilinosWrappers::PreconditionBase
Teuchos::RCP< Epetra_Operator >	preconditioner

Epetra_MpiComm	communicator

Detailed Description

A parsed ILU preconditioner which uses parameter files to choose between different options.

This object is a TrilinosWrappers::PreconditionILU which can be called in place of the preconditioner.

Definition at line 39 of file ilu.h.

Constructor & Destructor Documentation

◆ ILUPreconditioner()

ParsedLAC::ILUPreconditioner::ILUPreconditioner	(	const std::string &	name = `""`,
		const unsigned int &	ilu_fill = `0`,
		const double &	ilu_atol = `0.0`,
		const double &	ilu_rtol = `1.0`,
		const unsigned int &	overlap = `0`
	)

Constructor.

Build the preconditioner of a matrix using ILU.

Definition at line 26 of file ilu.cc.

References add_parameters().

Member Function Documentation

◆ initialize_preconditioner()

template<typename Matrix >

void ParsedLAC::ILUPreconditioner::initialize_preconditioner ( const Matrix & matrix )

Initialize the preconditioner using matrix.

Definition at line 57 of file ilu.cc.

References TrilinosWrappers::PreconditionILU::AdditionalData::ilu_atol, ilu_atol, TrilinosWrappers::PreconditionILU::AdditionalData::ilu_fill, ilu_fill, TrilinosWrappers::PreconditionILU::AdditionalData::ilu_rtol, ilu_rtol, ParameterAcceptor::initialize(), TrilinosWrappers::PreconditionILU::AdditionalData::overlap, and overlap.

◆ add_parameters()

void ParsedLAC::ILUPreconditioner::add_parameters ( )

private

Declare preconditioner options.

Definition at line 42 of file ilu.cc.

References ParameterAcceptor::add_parameter(), ilu_atol, ilu_fill, ilu_rtol, and overlap.

Referenced by ILUPreconditioner().

Member Data Documentation

◆ ilu_fill

unsigned int ParsedLAC::ILUPreconditioner::ilu_fill

private

This specifies the amount of additional fill-in elements besides the original sparse matrix structure.

If \f \(k\f\) is fill, the sparsity pattern of \f \(Ak+1\f\) is used for the storage of the result of the Gaussian elimination. This is known as \f \(ILU( k)\f\) in the literature. When ilu_fill is large, the preconditioner comes closer to a (direct) sparse LU decomposition.

Note: however, that this will drastically increase the memory requirement, especially when the preconditioner is used in 3D.

Definition at line 78 of file ilu.h.

Referenced by add_parameters(), and initialize_preconditioner().

◆ ilu_atol

double ParsedLAC::ILUPreconditioner::ilu_atol

private

The amount of perturbation to add to diagonal entries.

This parameter allows perturbation of the diagonal of the matrix, which sometimes can help to get better preconditioners especially in the case of bad conditioning. Before factorization, the diagonal entry \f \(a_{ii}\f\) is replaced by \f \(\alpha sign(a_{ii})+\beta a_{ii}\f\), where \f \(\alpha \geq 0\f\) is the absolute threshold ilu_atol and \f \(\beta \geq 1\f\) is the relative threshold ilu_rtol. The default values \f \((\alpha=1, \beta=1)\f\) therefore use the original, unmodified diagonal entry. Suggested values are in the order of \f \(10^{−5}\f\) to \f \(10^{−2}\f\) for ilu_atol and \f \(1.01\f\) for ilu_rtol.

Definition at line 94 of file ilu.h.

Referenced by add_parameters(), and initialize_preconditioner().

◆ ilu_rtol

double ParsedLAC::ILUPreconditioner::ilu_rtol

private

Scaling factor for diagonal entries.

This parameter allows perturbation of the diagonal of the matrix, which sometimes can help to get better preconditioners especially in the case of bad conditioning. Before factorization, the diagonal entry \f \(a_{ii}\f\) is replaced by \f \(\alpha sign(a_{ii})+\beta a_{ii}\f\), where \f \(\alpha \geq 0\f\) is the absolute threshold ilu_atol and \f \(\beta \geq 1\f\) is the relative threshold ilu_rtol. The default values \f \((\alpha=1, \beta=1)\f\) therefore use the original, unmodified diagonal entry. Suggested values are in the order of \f \(10^{−5}\f\) to \f \(10^{−2}\f\) for ilu_atol and \f \(1.01\f\) for ilu_rtol.

Definition at line 110 of file ilu.h.

Referenced by add_parameters(), and initialize_preconditioner().

◆ overlap

unsigned int ParsedLAC::ILUPreconditioner::overlap

private

Overlap between processors.

This determines how large the overlap of the local matrix portions on each processor in a parallel application should be. An overlap of 0 corresponds to a block diagonal decomposition on each processor, an overlap of 1 will additionally include a row \f \(j\f\) if there is a nonzero entry in column \f \(j\f\) in one of the own rows. Higher overlap numbers work accordingly in a recursive fashion. Increasing overlap will increase communication and storage cost. According to the IFPACK documentation, an overlap of 1 is often effective and values of more than 3 are rarely needed.

Definition at line 125 of file ilu.h.

Referenced by add_parameters(), and initialize_preconditioner().

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

include/parsed_lac/ilu.h
source/parsed_lac/ilu.cc

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ ILUPreconditioner()

Member Function Documentation

◆ initialize_preconditioner()

◆ add_parameters()

Member Data Documentation

◆ ilu_fill

◆ ilu_atol

◆ ilu_rtol

◆ overlap