Reference documentation for deal.II version GIT 7bd1c95dbb 2022-06-29 20:50:01+00:00
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Classes | Public Types | Public Member Functions | Protected Attributes | List of all members
SolverRelaxation< VectorType > Class Template Reference

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

Inheritance diagram for SolverRelaxation< VectorType >:
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Classes

struct  AdditionalData
 

Public Types

using vector_type = Vector< double >
 

Public Member Functions

 SolverRelaxation (SolverControl &cn, const AdditionalData &data=AdditionalData())
 
template<typename MatrixType , class RelaxationType >
void solve (const MatrixType &A, VectorType &x, const VectorType &b, const RelaxationType &R)
 
boost::signals2::connection connect (const std::function< SolverControl::State(const unsigned int iteration, const double check_value, const Vector< double > &current_iterate)> &slot)
 

Protected Attributes

GrowingVectorMemory< Vector< double > > static_vector_memory
 
VectorMemory< Vector< double > > & memory
 
boost::signals2::signal< SolverControl::State(const unsigned int iteration, const double check_value, const Vector< double > &current_iterate), StateCombiner > iteration_status
 

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
 
template<class Archive >
void serialize (Archive &ar, const unsigned int version)
 
using map_value_type = decltype(counter_map)::value_type
 
using map_iterator = decltype(counter_map)::iterator
 
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 std::mutex mutex
 
static ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (std::string arg1, std::string arg2)
 
void check_no_subscribers () const noexcept
 

Detailed Description

template<typename VectorType = Vector<double>>
class SolverRelaxation< VectorType >

Implementation of an iterative solver based on relaxation methods. The stopping criterion is the norm of the residual.

For the requirements on matrices and vectors in order to work with this class, see the documentation of the Solver base class.

Like all other solver classes, this class has a local structure called AdditionalData which is used to pass additional parameters to the solver, like damping parameters or the number of temporary vectors. We use this additional structure instead of passing these values directly to the constructor because this makes the use of the SolverSelector and other classes much easier and guarantees that these will continue to work even if number or type of the additional parameters for a certain solver changes. AdditionalData of this class currently does not contain any data.

Observing the progress of linear solver iterations

The solve() function of this class uses the mechanism described in the Solver base class to determine convergence. This mechanism can also be used to observe the progress of the iteration.

Definition at line 57 of file solver_relaxation.h.

Member Typedef Documentation

◆ vector_type

using SolverBase< Vector< double > >::vector_type = Vector< double >
inherited

An alias for the underlying vector type

Definition at line 346 of file solver.h.

Constructor & Destructor Documentation

◆ SolverRelaxation()

template<class VectorType >
SolverRelaxation< VectorType >::SolverRelaxation ( SolverControl cn,
const AdditionalData data = AdditionalData() 
)

Constructor.

Definition at line 89 of file solver_relaxation.h.

Member Function Documentation

◆ solve()

template<class VectorType >
template<typename MatrixType , class RelaxationType >
void SolverRelaxation< VectorType >::solve ( const MatrixType &  A,
VectorType &  x,
const VectorType &  b,
const RelaxationType &  R 
)

Solve the system \(Ax = b\) using the relaxation method \(x_{k+1} = R(x_k,b)\). The matrix A itself is only used to compute the residual.

Definition at line 99 of file solver_relaxation.h.

◆ connect()

boost::signals2::connection SolverBase< Vector< double > >::connect ( const std::function< SolverControl::State(const unsigned int iteration, const double check_value, const VectorType &current_iterate)> &  slot)
inherited

Connect a function object that will be called periodically within iterative solvers. This function is used to attach monitors to iterative solvers, either to determine when convergence has happened, or simply to observe the progress of an iteration. See the documentation of this class for more information.

Parameters
slotA function object specified here will, with each call, receive the number of the current iteration, the value that is used to check for convergence (typically the residual of the current iterate with respect to the linear system to be solved) and the currently best available guess for the current iterate. Note that some solvers do not update the approximate solution in every iteration but only after convergence or failure has been determined (GMRES is an example); in such cases, the vector passed as the last argument to the signal is simply the best approximate at the time the signal is called, but not the vector that will be returned if the signal's return value indicates that the iteration should be terminated. The function object must return a SolverControl::State value that indicates whether the iteration should continue, has failed, or has succeeded. The results of all connected functions will then be combined to determine what should happen with the iteration.
Returns
A connection object that represents the connection from the signal to the function object. It can be used to disconnect the function object again from the signal. See the documentation of the BOOST Signals2 library for more information on connection management.

Member Data Documentation

◆ static_vector_memory

GrowingVectorMemory<Vector< double > > SolverBase< Vector< double > >::static_vector_memory
mutableprotectedinherited

A static vector memory object to be used whenever no such object has been given to the constructor.

Definition at line 414 of file solver.h.

◆ memory

VectorMemory<Vector< double > >& SolverBase< Vector< double > >::memory
protectedinherited

A reference to an object that provides memory for auxiliary vectors.

Definition at line 419 of file solver.h.

◆ iteration_status

boost::signals2::signal< SolverControl::State(const unsigned int iteration, const double check_value, const Vector< double > & current_iterate), StateCombiner> SolverBase< Vector< double > >::iteration_status
protectedinherited

A signal that iterative solvers can execute at the end of every iteration (or in an otherwise periodic fashion) to find out whether we should continue iterating or not. The signal may call one or more slots that each will make this determination by themselves, and the result over all slots (function calls) will be determined by the StateCombiner object.

The arguments passed to the signal are (i) the number of the current iteration; (ii) the value that is used to determine convergence (oftentimes the residual, but in other cases other quantities may be used as long as they converge to zero as the iterate approaches the solution of the linear system); and (iii) a vector that corresponds to the current best guess for the solution at the point where the signal is called. Note that some solvers do not update the approximate solution in every iteration but only after convergence or failure has been determined (GMRES is an example); in such cases, the vector passed as the last argument to the signal is simply the best approximate at the time the signal is called, but not the vector that will be returned if the signal's return value indicates that the iteration should be terminated.

Definition at line 470 of file solver.h.


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