#include <deal.II/lac/precondition.h>

Inheritance diagram for PreconditionSOR< MatrixType >:

Public Types
using	AdditionalData = typename BaseClass::AdditionalData

using	size_type = types::global_dof_index

Public Member Functions
void	initialize (const MatrixType &A, const AdditionalData &parameters=AdditionalData())

void	clear ()

size_type	m () const

size_type	n () const

template<class VectorType >
void	vmult (VectorType &, const VectorType &) const

template<class VectorType >
void	Tvmult (VectorType &, const VectorType &) const

template<class VectorType >
void	step (VectorType &x, const VectorType &rhs) const

template<class VectorType >
void	Tstep (VectorType &x, const VectorType &rhs) const

template<class Archive >
void	serialize (Archive &ar, const unsigned int version)

Subscriptor functionality
Classes derived from Subscriptor provide a facility to subscribe to this object. This is mostly used by the SmartPointer class.
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

template<typename StreamType >
void	list_subscribers (StreamType &stream) const

void	list_subscribers () const

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

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

Protected Attributes
SmartPointer< const MatrixType, PreconditionRelaxation< MatrixType > >	A

double	relaxation

unsigned int	n_iterations

std::shared_ptr< PreconditionerType >	preconditioner

Private Types
using	PreconditionerType = internal::PreconditionRelaxation::PreconditionSORImpl< MatrixType >

using	BaseClass = PreconditionRelaxation< MatrixType, PreconditionerType >

using	map_value_type = decltype(counter_map)::value_type

using	map_iterator = decltype(counter_map)::iterator

Private Member Functions
void	check_no_subscribers () const noexcept

Private Attributes
std::atomic< unsigned int >	counter

std::map< std::string, unsigned int >	counter_map

std::vector< std::atomic< bool > * >	validity_pointers

const std::type_info *	object_info

Static Private Attributes
static std::mutex	mutex

Detailed Description

template<typename MatrixType = SparseMatrix<double>>
class PreconditionSOR< MatrixType >

SOR preconditioner using matrix built-in function.

Assuming the matrix A = D + L + U is split into its diagonal D as well as the strict lower and upper triangles L and U, then the SOR preconditioner with relaxation parameter r is

\[ P^{-1} = r (D+rL)^{-1}. \]

It is this operator P^-1, which is implemented by vmult() through forward substitution. Analogously, Tvmult() implements the operation of r(D+rU)^-1.

The SOR iteration itself can be directly written as

\[ x^{k+1} = x^k - r D^{-1} \bigl(L x^{k+1} + U x^k - b\bigr). \]

Using the right hand side b and the previous iterate x, this is the operation implemented by step().

The MatrixType class used is required to have functions precondition_SOR(VectorType&, const VectorType&, double) and precondition_TSOR(VectorType&, const VectorType&, double). This class satisfies the relaxation concept.

// Declare related objects
 
SparseMatrix<double> A;
Vector<double> x;
Vector<double> b;
SolverCG<> solver(...);
 
//...initialize and build A
 
// Define and initialize preconditioner
 
PreconditionSOR<SparseMatrix<double> > precondition;
precondition.initialize(
  A, PreconditionSOR<SparseMatrix<double>>::AdditionalData(.6));
 
solver.solve (A, x, b, precondition);

Definition at line 1540 of file precondition.h.

Member Typedef Documentation

◆ PreconditionerType

template<typename MatrixType = SparseMatrix<double>>

using PreconditionSOR< MatrixType >::PreconditionerType = internal::PreconditionRelaxation::PreconditionSORImpl<MatrixType>

private

Definition at line 1545 of file precondition.h.

◆ BaseClass

template<typename MatrixType = SparseMatrix<double>>

using PreconditionSOR< MatrixType >::BaseClass = PreconditionRelaxation<MatrixType, PreconditionerType>

private

Definition at line 1547 of file precondition.h.

◆ AdditionalData

template<typename MatrixType = SparseMatrix<double>>

using PreconditionSOR< MatrixType >::AdditionalData = typename BaseClass::AdditionalData

An alias to the base class AdditionalData.

Definition at line 1553 of file precondition.h.

◆ size_type

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

using PreconditionRelaxation< MatrixType, PreconditionerType >::size_type = types::global_dof_index

inherited

Declare type for container size.

Definition at line 412 of file precondition.h.

◆ map_value_type

using Subscriptor::map_value_type = decltype(counter_map)::value_type

privateinherited

The data type used in counter_map.

Definition at line 230 of file subscriptor.h.

◆ map_iterator

using Subscriptor::map_iterator = decltype(counter_map)::iterator

privateinherited

The iterator type used in counter_map.

Definition at line 235 of file subscriptor.h.

Member Function Documentation

◆ initialize()

template<typename MatrixType = SparseMatrix<double>>

void PreconditionSOR< MatrixType >::initialize	(	const MatrixType &	A,
		const AdditionalData &	parameters = `AdditionalData()`
	)

Initialize matrix and relaxation parameter. The matrix is just stored in the preconditioner object. The relaxation parameter should be larger than zero and smaller than 2 for numerical reasons. It defaults to 1.

◆ clear()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

void PreconditionRelaxation< MatrixType, PreconditionerType >::clear ( )

inherited

Release the matrix and reset its pointer.

◆ m()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

size_type PreconditionRelaxation< MatrixType, PreconditionerType >::m ( ) const

inherited

Return the dimension of the codomain (or range) space. Note that the matrix is of dimension \(m \times n\).

◆ n()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

size_type PreconditionRelaxation< MatrixType, PreconditionerType >::n ( ) const

inherited

Return the dimension of the domain space. Note that the matrix is of dimension \(m \times n\).

◆ vmult()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

template<class VectorType >

void PreconditionRelaxation< MatrixType, PreconditionerType >::vmult	(	VectorType &	,
		const VectorType &
	)		const

inherited

Apply preconditioner.

◆ Tvmult()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

template<class VectorType >

void PreconditionRelaxation< MatrixType, PreconditionerType >::Tvmult	(	VectorType &	,
		const VectorType &
	)		const

inherited

Apply transpose preconditioner. Since this is a symmetric preconditioner, this function is the same as vmult().

◆ step()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

template<class VectorType >

void PreconditionRelaxation< MatrixType, PreconditionerType >::step	(	VectorType &	x,
		const VectorType &	rhs
	)		const

inherited

Perform one step of the preconditioned Richardson iteration

◆ Tstep()

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

template<class VectorType >

void PreconditionRelaxation< MatrixType, PreconditionerType >::Tstep	(	VectorType &	x,
		const VectorType &	rhs
	)		const

inherited

Perform one transposed step of the preconditioned Richardson iteration.

◆ subscribe()

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

inherited

Subscribes a user of the object by storing the pointer validity. The subscriber may be identified by text supplied as identifier.

Definition at line 136 of file subscriptor.cc.

◆ unsubscribe()

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

inherited

Unsubscribes a user from the object.

Note: The identifier and the validity pointer must be the same as the one supplied to subscribe().

Definition at line 156 of file subscriptor.cc.

◆ n_subscriptions()

unsigned int Subscriptor::n_subscriptions ( ) const

inlineinherited

Return the present number of subscriptions to this object. This allows to use this class for reference counted lifetime determination where the last one to unsubscribe also deletes the object.

Definition at line 300 of file subscriptor.h.

◆ list_subscribers() [1/2]

template<typename StreamType >

void Subscriptor::list_subscribers ( StreamType & stream ) const

inlineinherited

List the subscribers to the input stream.

Definition at line 317 of file subscriptor.h.

◆ list_subscribers() [2/2]

void Subscriptor::list_subscribers ( ) const

inherited

List the subscribers to deallog.

Definition at line 204 of file subscriptor.cc.

◆ serialize()

template<class Archive >

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

inlineinherited

Read or write the data of this object to or from a stream for the purpose of serialization using the BOOST serialization library.

This function does not actually serialize any of the member variables of this class. The reason is that what this class stores is only who subscribes to this object, but who does so at the time of storing the contents of this object does not necessarily have anything to do with who subscribes to the object when it is restored. Consequently, we do not want to overwrite the subscribers at the time of restoring, and then there is no reason to write the subscribers out in the first place.

Definition at line 309 of file subscriptor.h.

◆ check_no_subscribers()

void Subscriptor::check_no_subscribers ( ) const

privatenoexceptinherited

Check that there are no objects subscribing to this object. If this check passes then it is safe to destroy the current object. It this check fails then this function will either abort or print an error message to deallog (by using the AssertNothrow mechanism), but will not throw an exception.

Note: Since this function is just a consistency check it does nothing in release mode.; If this function is called when there is an uncaught exception then, rather than aborting, this function prints an error message to the standard error stream and returns.

Definition at line 53 of file subscriptor.cc.

Member Data Documentation

◆ A

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

SmartPointer<const MatrixType, PreconditionRelaxation<MatrixType> > PreconditionRelaxation< MatrixType, PreconditionerType >::A

protectedinherited

Pointer to the matrix object.

Definition at line 505 of file precondition.h.

◆ relaxation

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

double PreconditionRelaxation< MatrixType, PreconditionerType >::relaxation

protectedinherited

Relaxation parameter.

Definition at line 510 of file precondition.h.

◆ n_iterations

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

unsigned int PreconditionRelaxation< MatrixType, PreconditionerType >::n_iterations

protectedinherited

Number of smoothing steps to be performed.

Definition at line 515 of file precondition.h.

◆ preconditioner

template<typename MatrixType = SparseMatrix<double>, typename PreconditionerType = IdentityMatrix>

std::shared_ptr<PreconditionerType> PreconditionRelaxation< MatrixType, PreconditionerType >::preconditioner

protectedinherited

Definition at line 520 of file precondition.h.

◆ counter

std::atomic<unsigned int> Subscriptor::counter

mutableprivateinherited

Store the number of objects which subscribed to this object. Initially, this number is zero, and upon destruction it shall be zero again (i.e. all objects which subscribed should have unsubscribed again).

The creator (and owner) of an object is counted in the map below if HE manages to supply identification.

We use the mutable keyword in order to allow subscription to constant objects also.

This counter may be read from and written to concurrently in multithreaded code: hence we use the std::atomic class template.

Definition at line 219 of file subscriptor.h.

◆ counter_map

std::map<std::string, unsigned int> Subscriptor::counter_map

mutableprivateinherited

In this map, we count subscriptions for each different identification string supplied to subscribe().

Definition at line 225 of file subscriptor.h.

◆ validity_pointers

std::vector<std::atomic<bool> *> Subscriptor::validity_pointers

mutableprivateinherited

In this vector, we store pointers to the validity bool in the SmartPointer objects that subscribe to this class.

Definition at line 241 of file subscriptor.h.

◆ object_info

const std::type_info* Subscriptor::object_info

mutableprivateinherited

Pointer to the typeinfo object of this object, from which we can later deduce the class name. Since this information on the derived class is neither available in the destructor, nor in the constructor, we obtain it in between and store it here.

Definition at line 249 of file subscriptor.h.

◆ mutex

std::mutex Subscriptor::mutex

staticprivateinherited

A mutex used to ensure data consistency when printing out the list of subscribers.

Definition at line 271 of file subscriptor.h.

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

include/deal.II/lac/precondition.h

Public Types

Public Member Functions

Static Public Member Functions

Protected Attributes

Private Types

Private Member Functions

Private Attributes

Static Private Attributes

Detailed Description

Member Typedef Documentation

◆ PreconditionerType

◆ BaseClass

◆ AdditionalData

◆ size_type

◆ map_value_type

◆ map_iterator

Member Function Documentation

◆ initialize()

◆ clear()

◆ m()

◆ n()

◆ vmult()

◆ Tvmult()

◆ step()

◆ Tstep()

◆ subscribe()

◆ unsubscribe()

◆ n_subscriptions()

◆ list_subscribers() [1/2]

◆ list_subscribers() [2/2]

◆ serialize()

◆ check_no_subscribers()

Member Data Documentation

◆ A

◆ relaxation

◆ n_iterations

◆ preconditioner

◆ counter

◆ counter_map

◆ validity_pointers

◆ object_info

◆ mutex