Nonoverlapping parallel preconditioner. More...

#include <dune/istl/novlpschwarz.hh>

Public Types
typedef P::domain_type	domain_type
	The domain type of the preconditioner.

typedef P::range_type	range_type
	The range type of the preconditioner.

typedef C	communication_type
	The type of the communication object.

typedef X::field_type	field_type
	The field type of the preconditioner.

Public Member Functions
	NonoverlappingBlockPreconditioner (P &prec, const communication_type &c)
	Constructor. More...

virtual void	pre (domain_type &x, range_type &b)
	Prepare the preconditioner. More...

virtual void	apply (domain_type &v, const range_type &d)
	Apply the preconditioner. More...

virtual void	post (domain_type &x)
	Clean up. More...

virtual SolverCategory::Category	category () const
	Category of the preconditioner (see SolverCategory::Category)

Detailed Description

template<class C, class P>
class Dune::NonoverlappingBlockPreconditioner< C, P >

Nonoverlapping parallel preconditioner.

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

Constructor & Destructor Documentation

◆ NonoverlappingBlockPreconditioner()

template<class C , class P >

Dune::NonoverlappingBlockPreconditioner< C, P >::NonoverlappingBlockPreconditioner	(	P &	prec,
		const communication_type &	c
	)

inline

Constructor.

constructor gets all parameters to operate the prec.

Parameters

prec	The sequential preconditioner.
c	The communication object for syncing owner and copy data points. (E.~g. OwnerOverlapCommunication )

Member Function Documentation

◆ apply()

template<class C , class P >

virtual void Dune::NonoverlappingBlockPreconditioner< C, P >::apply	(	domain_type &	v,
		const range_type &	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]	v	The update to be computed
	d	The current defect.

Implements Dune::Preconditioner< P::domain_type, P::range_type >.

◆ post()

template<class C , class P >

virtual void Dune::NonoverlappingBlockPreconditioner< C, P >::post ( domain_type & x )

inlinevirtual

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< P::domain_type, P::range_type >.

◆ pre()

template<class C , class P >

virtual void Dune::NonoverlappingBlockPreconditioner< C, P >::pre	(	domain_type &	x,
		range_type &	b
	)

inlinevirtual

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