Dune Core Modules (2.4.2)

Block parallel preconditioner. More...

#include <dune/istl/schwarz.hh>

Public Types

enum  { category =SolverCategory::overlapping }
 
typedef X domain_type
 The domain type of the preconditioner. More...
 
typedef Y range_type
 The range type of the preconditioner. More...
 
typedef X::field_type field_type
 The field type of the preconditioner.
 
typedef C communication_type
 The type of the communication object.. More...
 

Public Member Functions

 BlockPreconditioner (T &p, const communication_type &c)
 Constructor. More...
 
virtual void pre (X &x, Y &b)
 Prepare the preconditioner. More...
 
virtual void apply (X &v, const Y &d)
 Apply the preconditioner. More...
 
template<bool forward>
void apply (X &v, const Y &d)
 Apply one step of the preconditioner to the system A(v)=d. More...
 
virtual void post (X &x)
 Clean up. More...
 

Detailed Description

template<class X, class Y, class C, class T = Preconditioner<X,Y>>
class Dune::BlockPreconditioner< X, Y, C, T >

Block parallel preconditioner.

This is essentially a wrapper that takes a sequential preconditioner. In each step the sequential preconditioner is applied and then all owner data points are updated on all other processes.

Template Parameters
MThe type of the sequential matrix to use, e.g. BCRSMatrix or another matrix type fulfilling the matrix interface of ISTL.
XThe type of the sequential vector to use for the left hand side, e.g. BlockVector or another type fulfilling the ISTL vector interface.
YThe type of the sequential vector to use for the right hand side, e..g. BlockVector or another type fulfilling the ISTL vector interface.
CThe type of the communication object. This must either be OwnerOverlapCopyCommunication or a type implementing the same interface.
Thetype of the sequential preconditioner to use for approximately solving the local matrix block consisting of unknowns owned by the process. Has to implement the Preconditioner interface.

Member Typedef Documentation

◆ communication_type

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
typedef C Dune::BlockPreconditioner< X, Y, C, T >::communication_type

The type of the communication object..

This must either be OwnerOverlapCopyCommunication or a type implementing the same interface.

◆ domain_type

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
typedef X Dune::BlockPreconditioner< X, Y, C, T >::domain_type

The domain type of the preconditioner.

E.g. BlockVector or another type fulfilling the ISTL vector interface.

◆ range_type

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
typedef Y Dune::BlockPreconditioner< X, Y, C, T >::range_type

The range type of the preconditioner.

E.g. BlockVector or another type fulfilling the ISTL vector interface.

Member Enumeration Documentation

◆ anonymous enum

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
anonymous enum
Enumerator
category 

The category the precondtioner is part of.

Constructor & Destructor Documentation

◆ BlockPreconditioner()

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
Dune::BlockPreconditioner< X, Y, C, T >::BlockPreconditioner ( T &  p,
const communication_type c 
)
inline

Constructor.

constructor gets all parameters to operate the prec.

Parameters
pThe sequential preconditioner.
cThe communication object for syncing overlap and copy data points. (E.~g. OwnerOverlapCopyCommunication )

Member Function Documentation

◆ apply() [1/2]

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
virtual void Dune::BlockPreconditioner< X, Y, C, T >::apply ( X &  v,
const Y &  d 
)
inlinevirtual

Apply the preconditioner.

Apply one step of the preconditioner to the system A(v)=d.

On entry v=0 and d=b-A(x) (although this might not be computed in that way. On exit v contains the update, i.e one step computes \( v = M^{-1} d \) where \( M \) is the approximate inverse of the operator \( A \) characterizing the preconditioner.

Parameters
[out]vThe update to be computed
dThe current defect.

Implements Dune::Preconditioner< X, Y >.

◆ apply() [2/2]

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
template<bool forward>
void Dune::BlockPreconditioner< X, Y, C, T >::apply ( X &  v,
const Y &  d 
)
inlinevirtual

Apply one step of the preconditioner to the system A(v)=d.

On entry v=0 and d=b-A(x) (although this might not be computed in that way. On exit v contains the update, i.e one step computes \( v = M^{-1} d \) where \( M \) is the approximate inverse of the operator \( A \) characterizing the preconditioner.

Parameters
[out]vThe update to be computed
dThe current defect.

Implements Dune::Preconditioner< X, Y >.

◆ post()

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
virtual void Dune::BlockPreconditioner< X, Y, C, T >::post ( X &  x)
inlinevirtual

Clean up.

Clean up.

This method is called after the last apply call for the linear system to be solved. Memory may be deallocated safely here. x is the solution of the linear equation.

Parameters
xThe right hand side of the equation.

Implements Dune::Preconditioner< X, Y >.

◆ pre()

template<class X , class Y , class C , class T = Preconditioner<X,Y>>
virtual void Dune::BlockPreconditioner< X, Y, C, T >::pre ( X &  x,
Y &  b 
)
inlinevirtual

Prepare the preconditioner.

Prepare the preconditioner.

A solver solves a linear operator equation A(x)=b by applying one or several steps of the preconditioner. The method pre() is called before the first apply operation. b and x are right hand side and solution vector of the linear system respectively. It may. e.g., scale the system, allocate memory or compute a (I)LU decomposition. Note: The ILU decomposition could also be computed in the constructor or with a separate method of the derived method if several linear systems with the same matrix are to be solved.

Parameters
xThe left hand side of the equation.
bThe right hand side of the equation.

Implements Dune::Preconditioner< X, Y >.


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