![]() |
Reference documentation for deal.II version 9.6.0
|
#include <deal.II/lac/precondition.h>
Public Types | |
using | AdditionalData = typename BaseClass::AdditionalData |
using | size_type = types::global_dof_index |
using | EigenvalueInformation = internal::EigenvalueInformation |
Public Member Functions | |
void | initialize (const MatrixType &A, const AdditionalData ¶meters=AdditionalData()) |
void | clear () |
size_type | m () const |
size_type | n () const |
template<typename VectorType > | |
void | vmult (VectorType &, const VectorType &) const |
template<typename VectorType > | |
void | Tvmult (VectorType &, const VectorType &) const |
template<typename VectorType > | |
void | step (VectorType &x, const VectorType &rhs) const |
template<typename VectorType > | |
void | Tstep (VectorType &x, const VectorType &rhs) const |
template<typename VectorType > | |
EigenvalueInformation | estimate_eigenvalues (const VectorType &src) const |
double | get_relaxation () 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 |
AdditionalData | data |
std::shared_ptr< PreconditionerType > | preconditioner |
bool | eigenvalues_are_initialized |
Private Types | |
using | PreconditionerType |
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 |
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.
Definition at line 1722 of file precondition.h.
|
private |
Definition at line 1727 of file precondition.h.
|
private |
Definition at line 1729 of file precondition.h.
using PreconditionSOR< MatrixType >::AdditionalData = typename BaseClass::AdditionalData |
An alias to the base class AdditionalData.
Definition at line 1735 of file precondition.h.
|
inherited |
Declare type for container size.
Definition at line 572 of file precondition.h.
|
inherited |
Definition at line 665 of file precondition.h.
|
privateinherited |
The data type used in counter_map.
Definition at line 229 of file subscriptor.h.
|
privateinherited |
The iterator type used in counter_map.
Definition at line 234 of file subscriptor.h.
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.
|
inherited |
Release the matrix and reset its pointer.
|
inherited |
Return the dimension of the codomain (or range) space. Note that the matrix is of dimension \(m \times n\).
|
inherited |
Return the dimension of the domain space. Note that the matrix is of dimension \(m \times n\).
|
inherited |
Apply preconditioner.
|
inherited |
Apply transpose preconditioner. Since this is a symmetric preconditioner, this function is the same as vmult().
|
inherited |
Perform one step of the preconditioned Richardson iteration
|
inherited |
Perform one transposed step of the preconditioned Richardson iteration.
|
inherited |
Estimate eigenvalues and set relaxation parameter.
|
inherited |
Return the relaxation parameter. This function also allows to return the parameter in case it was internally determined by running an eigenvalue algorithm.
|
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 135 of file subscriptor.cc.
|
inherited |
Unsubscribes a user from the object.
identifier
and the validity
pointer must be the same as the one supplied to subscribe(). Definition at line 155 of file subscriptor.cc.
|
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.
|
inlineinherited |
List the subscribers to the input stream
.
Definition at line 317 of file subscriptor.h.
|
inherited |
List the subscribers to deallog
.
Definition at line 203 of file subscriptor.cc.
|
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.
|
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.
Definition at line 52 of file subscriptor.cc.
|
protectedinherited |
Pointer to the matrix object.
Definition at line 686 of file precondition.h.
|
protectedinherited |
Stores the additional data passed to the initialize function, obtained through a copy operation.
Definition at line 692 of file precondition.h.
|
protectedinherited |
Preconditioner.
Definition at line 697 of file precondition.h.
|
protectedinherited |
Stores whether the preconditioner has been set up and eigenvalues have been computed.
Definition at line 703 of file precondition.h.
|
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 218 of file subscriptor.h.
|
mutableprivateinherited |
In this map, we count subscriptions for each different identification string supplied to subscribe().
Definition at line 224 of file subscriptor.h.
|
mutableprivateinherited |
In this vector, we store pointers to the validity bool in the SmartPointer objects that subscribe to this class.
Definition at line 240 of file subscriptor.h.
|
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 248 of file subscriptor.h.
|
staticprivateinherited |
A mutex used to ensure data consistency when accessing the mutable
members of this class. This lock is used in the subscribe() and unsubscribe() functions, as well as in list_subscribers()
.
Definition at line 271 of file subscriptor.h.