Reference documentation for deal.II version GIT relicensing-233-g802318d791 2024-03-28 20:20:02+00:00
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Public Member Functions | Static Public Member Functions | Protected Attributes | Private Types | Private Member Functions | Private Attributes | Static Private Attributes | List of all members
MGSmootherBlock< MatrixType, RelaxationType, number > Class Template Referenceabstract

#include <deal.II/multigrid/mg_block_smoother.h>

Inheritance diagram for MGSmootherBlock< MatrixType, RelaxationType, number >:
Inheritance graph
[legend]

Public Member Functions

 MGSmootherBlock (const unsigned int steps=1, const bool variable=false, const bool symmetric=false, const bool transpose=false, const bool reverse=false)
 
template<typename MGMatrixType , typename MGRelaxationType >
void initialize (const MGMatrixType &matrices, const MGRelaxationType &smoothers)
 
void clear ()
 
void set_reverse (const bool)
 
virtual void smooth (const unsigned int level, BlockVector< number > &u, const BlockVector< number > &rhs) const
 
std::size_t memory_consumption () const
 
void set_steps (const unsigned int)
 
void set_variable (const bool)
 
void set_symmetric (const bool)
 
void set_transpose (const bool)
 
void set_debug (const unsigned int level)
 
virtual void smooth (const unsigned int level, VectorType &u, const VectorType &rhs) const =0
 
virtual void apply (const unsigned int level, VectorType &u, const VectorType &rhs) 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 ::ExceptionBaseExcInUse (int arg1, std::string arg2, std::string arg3)
 
static ::ExceptionBaseExcNoSubscriber (std::string arg1, std::string arg2)
 

Protected Attributes

GrowingVectorMemory< BlockVector< number > > vector_memory
 
unsigned int steps
 
bool variable
 
bool symmetric
 
bool transpose
 
unsigned int debug
 

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

MGLevelObject< LinearOperator< BlockVector< number > > > matrices
 
MGLevelObject< LinearOperator< BlockVector< number > > > smoothers
 
bool reverse
 
SmartPointer< VectorMemory< BlockVector< number > >, MGSmootherBlock< MatrixType, RelaxationType, number > > mem
 
std::atomic< unsigned intcounter
 
std::map< std::string, unsigned intcounter_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, typename RelaxationType, typename number>
class MGSmootherBlock< MatrixType, RelaxationType, number >

General smoother class for block vectors. This class gives complete freedom to the choice of a block smoother by being initialized with a matrix and a smoother object. Therefore, the smoother object for each level must be constructed by hand.

Definition at line 50 of file mg_block_smoother.h.

Member Typedef Documentation

◆ map_value_type

using Subscriptor::map_value_type = decltype(counter_map)::value_type
privateinherited

The data type used in counter_map.

Definition at line 229 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 234 of file subscriptor.h.

Constructor & Destructor Documentation

◆ MGSmootherBlock()

template<typename MatrixType , typename RelaxationType , typename number >
MGSmootherBlock< MatrixType, RelaxationType, number >::MGSmootherBlock ( const unsigned int  steps = 1,
const bool  variable = false,
const bool  symmetric = false,
const bool  transpose = false,
const bool  reverse = false 
)

Constructor.

Member Function Documentation

◆ initialize()

template<typename MatrixType , typename RelaxationType , typename number >
template<typename MGMatrixType , typename MGRelaxationType >
void MGSmootherBlock< MatrixType, RelaxationType, number >::initialize ( const MGMatrixType &  matrices,
const MGRelaxationType &  smoothers 
)

Initialize for matrices. The parameter matrices can be any object having functions get_minlevel() and get_maxlevel() as well as an operator[] returning a reference to MatrixType.

The same convention is used for the parameter smoothers, such that operator[] returns the object doing the block-smoothing on a single level.

This function stores pointers to the level matrices and smoothing operator for each level.

◆ clear()

template<typename MatrixType , typename RelaxationType , typename number >
void MGSmootherBlock< MatrixType, RelaxationType, number >::clear ( )
virtual

Empty all vectors.

Implements MGSmootherBase< VectorType >.

◆ set_reverse()

template<typename MatrixType , typename RelaxationType , typename number >
void MGSmootherBlock< MatrixType, RelaxationType, number >::set_reverse ( const bool  )

Switch on/off reversed. This is mutually exclusive with transpose().

◆ smooth() [1/2]

template<typename MatrixType , typename RelaxationType , typename number >
virtual void MGSmootherBlock< MatrixType, RelaxationType, number >::smooth ( const unsigned int  level,
BlockVector< number > &  u,
const BlockVector< number > &  rhs 
) const
virtual

Implementation of the interface for Multigrid. This function does nothing, which by comparison with the definition of this function means that the smoothing operator equals the null operator.

◆ memory_consumption()

template<typename MatrixType , typename RelaxationType , typename number >
std::size_t MGSmootherBlock< MatrixType, RelaxationType, number >::memory_consumption ( ) const

Memory used by this object.

◆ set_steps()

void MGSmoother< BlockVector< number > >::set_steps ( const unsigned int  )
inherited

Modify the number of smoothing steps on finest level.

◆ set_variable()

void MGSmoother< BlockVector< number > >::set_variable ( const bool  )
inherited

Switch on/off variable smoothing.

◆ set_symmetric()

void MGSmoother< BlockVector< number > >::set_symmetric ( const bool  )
inherited

Switch on/off symmetric smoothing.

◆ set_transpose()

void MGSmoother< BlockVector< number > >::set_transpose ( const bool  )
inherited

Switch on/off transposed smoothing. The effect is overridden by set_symmetric().

◆ set_debug()

void MGSmoother< BlockVector< number > >::set_debug ( const unsigned int  level)
inherited

Set debug to a nonzero value to get debug information logged to deallog. Increase to get more information

◆ smooth() [2/2]

template<typename VectorType >
virtual void MGSmootherBase< VectorType >::smooth ( const unsigned int  level,
VectorType &  u,
const VectorType &  rhs 
) const
pure virtualinherited

Smoothing function that smooths the content in u given the right hand side vector rhs. This is the function used in multigrid methods.

Implemented in MGSmootherIdentity< VectorType >, MGSmootherRelaxation< MatrixType, RelaxationType, VectorType >, mg::SmootherRelaxation< RelaxationType, VectorType >, and MGSmootherPrecondition< MatrixType, PreconditionerType, VectorType >.

◆ apply()

template<typename VectorType >
void MGSmootherBase< VectorType >::apply ( const unsigned int  level,
VectorType &  u,
const VectorType &  rhs 
) const
virtualinherited

As opposed to the smooth() function, this function applies the action of the smoothing, overwriting the previous content in the vector u. This function must be equivalent to the following code

u = 0;
smooth(level, u, rhs);
virtual void smooth(const unsigned int level, BlockVector< number > &u, const BlockVector< number > &rhs) const
unsigned int level
Definition grid_out.cc:4616

but can usually be implemented more efficiently than the former. If a particular smoother does not override the apply() method, the default implementation as described here is used.

In the multigrid preconditioner interfaces, the apply() method is used for the pre-smoothing operation because the previous content in the solution vector needs to be overwritten for a new incoming residual. On the other hand, all subsequent operations need to smooth the content already present in the vector u given the right hand side, which is done by smooth().

Reimplemented in MGSmootherRelaxation< MatrixType, RelaxationType, VectorType >, mg::SmootherRelaxation< RelaxationType, VectorType >, and MGSmootherPrecondition< MatrixType, PreconditionerType, VectorType >.

Definition at line 33 of file mg_base.cc.

◆ 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 135 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 155 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 203 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 52 of file subscriptor.cc.

Member Data Documentation

◆ matrices

template<typename MatrixType , typename RelaxationType , typename number >
MGLevelObject<LinearOperator<BlockVector<number> > > MGSmootherBlock< MatrixType, RelaxationType, number >::matrices
private

Pointer to the matrices.

Definition at line 111 of file mg_block_smoother.h.

◆ smoothers

template<typename MatrixType , typename RelaxationType , typename number >
MGLevelObject<LinearOperator<BlockVector<number> > > MGSmootherBlock< MatrixType, RelaxationType, number >::smoothers
private

Pointer to the matrices.

Definition at line 116 of file mg_block_smoother.h.

◆ reverse

template<typename MatrixType , typename RelaxationType , typename number >
bool MGSmootherBlock< MatrixType, RelaxationType, number >::reverse
private

Reverse?

Definition at line 121 of file mg_block_smoother.h.

◆ mem

template<typename MatrixType , typename RelaxationType , typename number >
SmartPointer<VectorMemory<BlockVector<number> >, MGSmootherBlock<MatrixType, RelaxationType, number> > MGSmootherBlock< MatrixType, RelaxationType, number >::mem
private

Memory for auxiliary vectors.

Definition at line 128 of file mg_block_smoother.h.

◆ vector_memory

GrowingVectorMemory<BlockVector< number > > MGSmoother< BlockVector< number > >::vector_memory
mutableprotectedinherited

A memory object to be used for temporary vectors.

The object is marked as mutable since we will need to use it to allocate temporary vectors also in functions that are const.

Definition at line 99 of file mg_smoother.h.

◆ steps

unsigned int MGSmoother< BlockVector< number > >::steps
protectedinherited

Number of smoothing steps on the finest level. If no variable smoothing is chosen, this is the number of steps on all levels.

Definition at line 105 of file mg_smoother.h.

◆ variable

bool MGSmoother< BlockVector< number > >::variable
protectedinherited

Variable smoothing: double the number of smoothing steps whenever going to the next coarser level

Definition at line 111 of file mg_smoother.h.

◆ symmetric

bool MGSmoother< BlockVector< number > >::symmetric
protectedinherited

Symmetric smoothing: in the smoothing iteration, alternate between the relaxation method and its transpose.

Definition at line 117 of file mg_smoother.h.

◆ transpose

bool MGSmoother< BlockVector< number > >::transpose
protectedinherited

Use the transpose of the relaxation method instead of the method itself. This has no effect if symmetric smoothing is chosen.

Definition at line 123 of file mg_smoother.h.

◆ debug

unsigned int MGSmoother< BlockVector< number > >::debug
protectedinherited

Output debugging information to deallog if this is nonzero.

Definition at line 128 of file mg_smoother.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 218 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 224 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 240 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 248 of file subscriptor.h.

◆ mutex

std::mutex Subscriptor::mutex
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.


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