Dune Core Modules (2.4.2)

Sequential Gauss Seidel preconditioner. More...

#include <dune/istl/preconditioners.hh>

Public Types

enum  { category =SolverCategory::sequential }
 
typedef M matrix_type
 The matrix type the preconditioner is for.
 
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

 SeqGS (const M &A, int n, field_type w)
 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...
 
virtual void post (X &x)
 Clean up. More...
 

Detailed Description

template<class M, class X, class Y, int l = 1>
class Dune::SeqGS< M, X, Y, l >

Sequential Gauss Seidel preconditioner.

Wraps the naked ISTL generic block Gauss-Seidel preconditioner into the solver framework.

Template Parameters
MThe matrix type to operate on
XType of the update
YType of the defect
lThe block level to invert. Default is 1

Member Enumeration Documentation

◆ anonymous enum

template<class M , class X , class Y , int l = 1>
anonymous enum
Enumerator
category 

The category the preconditioner is part of.

Constructor & Destructor Documentation

◆ SeqGS()

template<class M , class X , class Y , int l = 1>
Dune::SeqGS< M, X, Y, l >::SeqGS ( const M &  A,
int  n,
field_type  w 
)
inline

Constructor.

Constructor gets all parameters to operate the prec.

Parameters
AThe matrix to operate on.
nThe number of iterations to perform.
wThe relaxation factor.

Member Function Documentation

◆ apply()

template<class M , class X , class Y , int l = 1>
virtual void Dune::SeqGS< M, X, Y, l >::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 >.

References Dune::dbgs().

◆ post()

template<class M , class X , class Y , int l = 1>
virtual void Dune::SeqGS< M, X, Y, l >::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 >.

References DUNE_UNUSED_PARAMETER.

◆ pre()

template<class M , class X , class Y , int l = 1>
virtual void Dune::SeqGS< M, X, Y, l >::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 >.

References DUNE_UNUSED_PARAMETER.


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