Reference documentation for deal.II version Git 16b398077e 2020-12-04 17:16:12 -0500
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Public Types | Public Member Functions | Static Public Member Functions | Protected Attributes | Private Attributes | List of all members
PreconditionSelector< MatrixType, VectorType > Class Template Reference

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

Inheritance diagram for PreconditionSelector< MatrixType, VectorType >:
[legend]

Public Types

using size_type = typename MatrixType::size_type
 

Public Member Functions

 PreconditionSelector (const std::string &preconditioning, const typename VectorType::value_type &omega=1.)
 
virtual ~PreconditionSelector () override
 
void use_matrix (const MatrixType &M)
 
size_type m () const
 
size_type n () const
 
virtual void vmult (VectorType &dst, const VectorType &src) const
 
virtual void Tvmult (VectorType &dst, const VectorType &src) 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 std::string get_precondition_names ()
 
static ::ExceptionBaseExcNoMatrixGivenToUse ()
 
static ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (std::string arg1, std::string arg2)
 

Protected Attributes

std::string preconditioning
 

Private Attributes

SmartPointer< const MatrixType, PreconditionSelector< MatrixType, VectorType > > A
 
const VectorType::value_type omega
 

Detailed Description

template<typename MatrixType = SparseMatrix<double>, typename VectorType = ::Vector<double>>
class PreconditionSelector< MatrixType, VectorType >

Selects the preconditioner. The constructor of this class takes the name of the preconditioning and the damping parameter omega of the preconditioning and the use_matrix function takes the matrix that is used by the matrix-builtin precondition functions. Each time, the operator() function is called, this preselected preconditioner, this matrix and this omega is used for the preconditioning. This class is designed for being used as argument of the solve function of a Solver and it covers the selection of all matrix-builtin precondition functions. The selection of other preconditioners, like BlockSOR or ILU should be handled in derived classes by the user.

Usage

The simplest use of this class is the following:

// generate a @p SolverControl and a @p VectorMemory
SolverControl control;
// generate a solver
SolverCG<SparseMatrix<double>, Vector<double> > solver(control, memory);
// generate a @p PreconditionSelector
preconditioning("jacobi", 1.);
// give a matrix whose diagonal entries are to be used for the
// preconditioning. Generally the matrix of the linear equation system Ax=b.
preconditioning.use_matrix(A);
// call the @p solve function with this preconditioning as last argument
solver.solve(A,x,b,preconditioning);

The same example where also the SolverSelector class is used reads

// generate a @p SolverControl and a @p VectorMemory
SolverControl control;
// generate a @p SolverSelector that calls the @p SolverCG
solver_selector("cg", control, memory);
// generate a @p PreconditionSelector
preconditioning("jacobi", 1.);
preconditioning.use_matrix(A);
solver_selector.solve(A,x,b,preconditioning);

Now the use of the SolverSelector in combination with the PreconditionSelector allows the user to select both, the solver and the preconditioner, at the beginning of their program and each time the solver is started (that is several times e.g. in a nonlinear iteration) this preselected solver and preconditioner is called.

Definition at line 100 of file precondition_selector.h.

Member Typedef Documentation

◆ size_type

template<typename MatrixType = SparseMatrix<double>, typename VectorType = ::Vector<double>>
using PreconditionSelector< MatrixType, VectorType >::size_type = typename MatrixType::size_type

Declare type for container size.

Definition at line 106 of file precondition_selector.h.

Constructor & Destructor Documentation

◆ PreconditionSelector()

template<typename MatrixType , typename VectorType >
PreconditionSelector< MatrixType, VectorType >::PreconditionSelector ( const std::string &  preconditioning,
const typename VectorType::value_type &  omega = 1. 
)

Constructor. omega denotes the damping parameter of the preconditioning.

Definition at line 205 of file precondition_selector.h.

◆ ~PreconditionSelector()

template<typename MatrixType , typename VectorType >
PreconditionSelector< MatrixType, VectorType >::~PreconditionSelector ( )
overridevirtual

Destructor.

Definition at line 214 of file precondition_selector.h.

Member Function Documentation

◆ use_matrix()

template<typename MatrixType , typename VectorType >
void PreconditionSelector< MatrixType, VectorType >::use_matrix ( const MatrixType &  M)

Takes the matrix that is needed for preconditionings that involves a matrix. e.g. for precondition_jacobi, ~_sor, ~_ssor.

Definition at line 223 of file precondition_selector.h.

◆ m()

template<typename MatrixType , typename VectorType >
PreconditionSelector< MatrixType, VectorType >::size_type PreconditionSelector< MatrixType, VectorType >::m ( ) const
inline

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

Definition at line 231 of file precondition_selector.h.

◆ n()

template<typename MatrixType , typename VectorType >
PreconditionSelector< MatrixType, VectorType >::size_type PreconditionSelector< MatrixType, VectorType >::n ( ) const
inline

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

Definition at line 240 of file precondition_selector.h.

◆ vmult()

template<typename MatrixType , typename VectorType >
void PreconditionSelector< MatrixType, VectorType >::vmult ( VectorType dst,
const VectorType src 
) const
virtual

Precondition procedure. Calls the preconditioning that was specified in the constructor.

Definition at line 250 of file precondition_selector.h.

◆ Tvmult()

template<typename MatrixType , typename VectorType >
void PreconditionSelector< MatrixType, VectorType >::Tvmult ( VectorType dst,
const VectorType src 
) const
virtual

Transpose precondition procedure. Calls the preconditioning that was specified in the constructor.

Definition at line 281 of file precondition_selector.h.

◆ get_precondition_names()

template<typename MatrixType , typename VectorType >
std::string PreconditionSelector< MatrixType, VectorType >::get_precondition_names ( )
static

Get the names of all implemented preconditionings. The list of possible options includes:

  • "none"
  • "jacobi"
  • "sor"
  • "ssor"

Definition at line 313 of file precondition_selector.h.

◆ 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.

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.

Member Data Documentation

◆ preconditioning

template<typename MatrixType = SparseMatrix<double>, typename VectorType = ::Vector<double>>
std::string PreconditionSelector< MatrixType, VectorType >::preconditioning
protected

Stores the name of the preconditioning.

Definition at line 184 of file precondition_selector.h.

◆ A

template<typename MatrixType = SparseMatrix<double>, typename VectorType = ::Vector<double>>
SmartPointer<const MatrixType, PreconditionSelector<MatrixType, VectorType> > PreconditionSelector< MatrixType, VectorType >::A
private

Matrix that is used for the matrix-builtin preconditioning function. cf. also PreconditionUseMatrix.

Definition at line 192 of file precondition_selector.h.

◆ omega

template<typename MatrixType = SparseMatrix<double>, typename VectorType = ::Vector<double>>
const VectorType::value_type PreconditionSelector< MatrixType, VectorType >::omega
private

Stores the damping parameter of the preconditioner.

Definition at line 197 of file precondition_selector.h.


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