Reference documentation for deal.II version Git 3f1f337db3 2021-10-23 13:19:02 -0600
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Classes | Public Member Functions | Static Public Member Functions | Protected Member Functions | Protected Attributes | List of all members
PETScWrappers::PreconditionBlockJacobi Class Reference

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

Inheritance diagram for PETScWrappers::PreconditionBlockJacobi:
[legend]

Classes

struct  AdditionalData
 

Public Member Functions

 PreconditionBlockJacobi ()=default
 
 PreconditionBlockJacobi (const MatrixBase &matrix, const AdditionalData &additional_data=AdditionalData())
 
 PreconditionBlockJacobi (const MPI_Comm &communicator, const AdditionalData &additional_data=AdditionalData())
 
void initialize (const MatrixBase &matrix, const AdditionalData &additional_data=AdditionalData())
 
void clear ()
 
void vmult (VectorBase &dst, const VectorBase &src) const
 
void Tvmult (VectorBase &dst, const VectorBase &src) const
 
const PC & get_pc () 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 Member Functions

void initialize ()
 
void create_pc ()
 
 operator Mat () const
 

Protected Attributes

AdditionalData additional_data
 
PC pc
 
Mat matrix
 

Detailed Description

A class that implements the interface to use the PETSc Block Jacobi preconditioner. PETSc defines the term "block Jacobi" as a preconditioner in which it looks at a number of diagonal blocks of the matrix and then defines a preconditioner in which the preconditioner matrix has the same block structure as only these diagonal blocks, and each diagonal block of the preconditioner is an approximation of the inverse of the corresponding block of the original matrix. The blocking structure of the matrix is determined by the association of degrees of freedom to the individual processors in an MPI-parallel job. If you use this preconditioner on a sequential job (or an MPI job with only one process) then the entire matrix is the only block.

By default, PETSc uses an ILU(0) decomposition of each diagonal block of the matrix for preconditioning. This can be changed, as is explained in the relevant section of the PETSc manual, but is not implemented here.

See the comment in the base class PreconditionBase for when this preconditioner may or may not work.

Definition at line 222 of file petsc_precondition.h.

Constructor & Destructor Documentation

◆ PreconditionBlockJacobi() [1/3]

PETScWrappers::PreconditionBlockJacobi::PreconditionBlockJacobi ( )
default

Empty Constructor. You need to call initialize() before using this object.

◆ PreconditionBlockJacobi() [2/3]

PreconditionBlockJacobi< MatrixType, inverse_type >::PreconditionBlockJacobi ( const MatrixBase matrix,
const AdditionalData additional_data = AdditionalData() 
)

Constructor. Take the matrix which is used to form the preconditioner, and additional flags if there are any.

Definition at line 189 of file petsc_precondition.cc.

◆ PreconditionBlockJacobi() [3/3]

PreconditionBlockJacobi< MatrixType, inverse_type >::PreconditionBlockJacobi ( const MPI_Comm communicator,
const AdditionalData additional_data = AdditionalData() 
)

Same as above but without setting a matrix to form the preconditioner. Intended to be used with SLEPc objects.

Definition at line 175 of file petsc_precondition.cc.

Member Function Documentation

◆ initialize() [1/2]

void PreconditionBlockJacobi< MatrixType, inverse_type >::initialize ( const MatrixBase matrix,
const AdditionalData additional_data = AdditionalData() 
)

Initialize the preconditioner object and calculate all data that is necessary for applying it in a solver. This function is automatically called when calling the constructor with the same arguments and is only used if you create the preconditioner without arguments.

Definition at line 208 of file petsc_precondition.cc.

◆ initialize() [2/2]

void PreconditionBlockJacobi< MatrixType, inverse_type >::initialize ( )
protected

Initialize the preconditioner object without knowing a particular matrix. This function sets up appropriate parameters to the underlying PETSc object after it has been created.

Definition at line 197 of file petsc_precondition.cc.

◆ clear()

void PETScWrappers::PreconditionBase::clear ( )
inherited

Destroys the preconditioner, leaving an object like just after having called the constructor.

Definition at line 52 of file petsc_precondition.cc.

◆ vmult()

void PETScWrappers::PreconditionBase::vmult ( VectorBase dst,
const VectorBase src 
) const
inherited

Apply the preconditioner once to the given src vector.

Definition at line 66 of file petsc_precondition.cc.

◆ Tvmult()

void PETScWrappers::PreconditionBase::Tvmult ( VectorBase dst,
const VectorBase src 
) const
inherited

Apply the transpose preconditioner once to the given src vector.

Definition at line 76 of file petsc_precondition.cc.

◆ get_pc()

const PC & PETScWrappers::PreconditionBase::get_pc ( ) const
inherited

Give access to the underlying PETSc object.

Definition at line 113 of file petsc_precondition.cc.

◆ create_pc()

void PETScWrappers::PreconditionBase::create_pc ( )
protectedinherited

Internal function to create the PETSc preconditioner object. Fails if called twice.

Definition at line 86 of file petsc_precondition.cc.

◆ operator Mat()

PETScWrappers::PreconditionBase::operator Mat ( ) const
protectedinherited

Conversion operator to get a representation of the matrix that represents this preconditioner. We use this inside the actual solver, where we need to pass this matrix to the PETSc solvers.

Definition at line 119 of file petsc_precondition.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 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 301 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 318 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 310 of file subscriptor.h.

Member Data Documentation

◆ additional_data

AdditionalData PETScWrappers::PreconditionBlockJacobi::additional_data
protected

Store a copy of the flags for this particular preconditioner.

Definition at line 269 of file petsc_precondition.h.

◆ pc

PC PETScWrappers::PreconditionBase::pc
protectedinherited

the PETSc preconditioner object

Definition at line 101 of file petsc_precondition.h.

◆ matrix

Mat PETScWrappers::PreconditionBase::matrix
protectedinherited

A pointer to the matrix that acts as a preconditioner.

Definition at line 106 of file petsc_precondition.h.


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