Reference documentation for deal.II version GIT 891e5cc501 2022-12-03 00:25:01+00:00
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Public Types | Public Member Functions | Static Public Member Functions | Protected Attributes | Private Types | Private Member Functions | Private Attributes | Static 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 Types

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

SmartPointer< const MatrixType, PreconditionSelector< MatrixType, VectorType > > A
 
const VectorType::value_type omega
 
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>, 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);
SmartPointer< const MatrixType, PreconditionSelector< MatrixType, VectorType > > A
SymmetricTensor< 2, dim, Number > b(const Tensor< 2, dim, Number > &F)

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 101 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 107 of file precondition_selector.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.

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 206 of file precondition_selector.h.

◆ ~PreconditionSelector()

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

Destructor.

Definition at line 215 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 224 of file precondition_selector.h.

◆ m()

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

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

Definition at line 232 of file precondition_selector.h.

◆ n()

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

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

Definition at line 241 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 251 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 282 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 314 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 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

◆ 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 185 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 193 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 198 of file precondition_selector.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: