Dune::ParSSOR< M, X, Y, C > Class Template Reference

A parallel SSOR preconditioner. More...

#include <dune/istl/schwarz.hh>

Public Types
enum	{ category =SolverCategory::overlapping }
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.
typedef C	communication_type
	The type of the communication object.

Public Member Functions
	ParSSOR (const matrix_type &A, int n, field_type w, 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 precondtioner. More...
virtual void	post (X &x)
	Clean up. More...

Detailed Description

template<class M, class X, class Y, class C>
class Dune::ParSSOR< M, X, Y, C >

A parallel SSOR preconditioner.

Template Parameters

M	The type of the sequential matrix to use, e.g. BCRSMatrix or another matrix type fulfilling the matrix interface of ISTL.
X	The type of the sequential vector to use for the left hand side, e.g. BlockVector or another type fulfilling the ISTL vector interface.
Y	The type of the sequential vector to use for the right hand side, e..g. BlockVector or another type fulfilling the ISTL vector interface.
C	The type of the communication object. This must either be OwnerOverlapCopyCommunication or a type implementing the same interface.

Member Enumeration Documentation

anonymous enum

template<class M , class X , class Y , class C >

anonymous enum

Enumerator
category	The category the precondtioner is part of.

Constructor & Destructor Documentation

ParSSOR()

template<class M , class X , class Y , class C >

Dune::ParSSOR< M, X, Y, C >::ParSSOR ( const matrix_type &  A, int  n, field_type  w, const communication_type &  c  )

inline

Constructor.

constructor gets all parameters to operate the prec.

Parameters

A	The matrix to operate on.
n	The number of iterations to perform.
w	The relaxation factor.
c	The communication object for syncing overlap and copy data points. (E.~g. OwnerOverlapCopyCommunication )

Member Function Documentation

apply()

template<class M , class X , class Y , class C >

virtual void Dune::ParSSOR< M, X, Y, C >::apply ( X &  v, const Y &  d  )

inlinevirtual

Apply the precondtioner.

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]	v	The update to be computed
	d	The current defect.

Implements Dune::Preconditioner< X, Y >.

References Dune::bsorb(), and Dune::bsorf().

post()

template<class M , class X , class Y , class C >

virtual void Dune::ParSSOR< M, X, Y, C >::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

x	The right hand side of the equation.

Implements Dune::Preconditioner< X, Y >.

pre()

template<class M , class X , class Y , class C >

virtual void Dune::ParSSOR< M, X, Y, C >::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

x	The left hand side of the equation.
b	The right hand side of the equation.

Implements Dune::Preconditioner< X, Y >.

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

• dune/istl/schwarz.hh