Reference documentation for deal.II version GIT 7bd1c95dbb 2022-06-29 20:50:01+00:00
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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 >:
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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
 

Static Public Member Functions

static std::string get_precondition_names ()
 
static ::ExceptionBaseExcNoMatrixGivenToUse ()
 

Protected Attributes

std::string preconditioning
 

Private Attributes

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

Subscriptor functionality

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

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
 
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)
 
static ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (std::string arg1, std::string arg2)
 
using map_value_type = decltype(counter_map)::value_type
 
using map_iterator = decltype(counter_map)::iterator
 
static std::mutex mutex
 
void check_no_subscribers () const noexcept
 

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 100 of file precondition_selector.h.


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