dune-istl  2.2.0
Public Types | Public Member Functions
Dune::Richardson< X, Y > Class Template Reference

Richardson preconditioner. More...

#include <dune/istl/preconditioners.hh>

Inheritance diagram for Dune::Richardson< X, Y >:
Inheritance graph

List of all members.

Public Types

enum  { category = SolverCategory::sequential }
typedef X domain_type
 The domain type of the preconditioner.
typedef Y range_type
 The range type of the preconditioner.
typedef X::field_type field_type
 The field type of the preconditioner.

Public Member Functions

 Richardson (field_type w=1.0)
 Constructor.
virtual void pre (X &x, Y &b)
 Prepare the preconditioner.
virtual void apply (X &v, const Y &d)
 Apply the precondioner.
virtual void post (X &x)
 Clean up.

Detailed Description

template<class X, class Y>
class Dune::Richardson< X, Y >

Richardson preconditioner.

Multiply simply by a constant.
Template Parameters:
XType of the update
YType of the defect

Member Typedef Documentation

template<class X , class Y >
typedef X Dune::Richardson< X, Y >::domain_type

The domain type of the preconditioner.

Reimplemented from Dune::Preconditioner< X, Y >.

template<class X , class Y >
typedef X::field_type Dune::Richardson< X, Y >::field_type

The field type of the preconditioner.

Reimplemented from Dune::Preconditioner< X, Y >.

template<class X , class Y >
typedef Y Dune::Richardson< X, Y >::range_type

The range type of the preconditioner.

Reimplemented from Dune::Preconditioner< X, Y >.


Member Enumeration Documentation

template<class X , class Y >
anonymous enum
Enumerator:
category 

The category the preconditioner is part of.


Constructor & Destructor Documentation

template<class X , class Y >
Dune::Richardson< X, Y >::Richardson ( field_type  w = 1.0)
inline

Constructor.

Constructor gets all parameters to operate the prec.

Parameters:
wThe relaxation factor.

Member Function Documentation

template<class X , class Y >
virtual void Dune::Richardson< X, Y >::apply ( X &  v,
const Y &  d 
)
inlinevirtual

Apply the precondioner.

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 >.

template<class X , class Y >
virtual void Dune::Richardson< X, Y >::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 >.

template<class X , class Y >
virtual void Dune::Richardson< X, Y >::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: