dune-istl  2.7.0
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Dune::Richardson< M, X, Y, l > Class Template Reference

Sequential ILU0 preconditioner. More...

#include <dune/istl/preconditioners.hh>

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

Public Types

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. More...
 
typedef Simd::Scalar< field_typescalar_field_type
 scalar type underlying the field_type More...
 

Public Member Functions

 Richardson (scalar_field_type w=1.0)
 Constructor. More...
 
 Richardson (const ParameterTree &configuration)
 Constructor. More...
 
virtual void pre (X &x, Y &b)
 Prepare the preconditioner. More...
 
virtual void apply (X &v, const Y &d)
 Apply the precondioner. More...
 
virtual void post (X &x)
 Clean up. More...
 
virtual SolverCategory::Category category () const
 Category of the preconditioner (see SolverCategory::Category) More...
 

Detailed Description

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

Sequential ILU0 preconditioner.

Wraps the naked ISTL generic ILU0 preconditioner into the solver framework.

Template Parameters
MThe matrix type to operate on
XType of the update
YType of the defect
lIgnored. Just there to have the same number of template arguments as other preconditioners.
Deprecated:
Use SeqILU instead!

Constructor.

Constructor gets all parameters to operate the prec.

Parameters
AThe matrix to operate on.
wThe relaxation factor.

Constructor.

Parameters
AThe matrix to operate on.
configurationParameterTree containing preconditioner parameters.
ParameterTree Key Meaning
relaxation The relaxation factor

See ISTL_Factory for the ParameterTree layout and examples.

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.

Note
if a preconditioner is copied (e.g. for a second thread) again the pre() method has to be called to ensure proper memory mangement.
X x(0.0);
Y b = ...; // rhs
Preconditioner<X,Y> prec(...);
prec.pre(x,b); // prepare the preconditioner
prec.apply(x,b); // can be called multiple times now...
prec.post(x); // cleanup internal state
Parameters
xThe left hand side of the equation.
bThe right hand side of the equation.

Apply the preconditoner.

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.

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.

Sequential ILU(n) preconditioner.

Wraps the naked ISTL generic ILU(n) preconditioner into the solver framework.

Template Parameters
MThe matrix type to operate on
XType of the update
YType of the defect
lIgnored. Just there to have the same number of template arguments as other preconditioners.
Deprecated:
Use SeqILU instead!

Constructor.

Constructor gets all parameters to operate the prec.

Parameters
AThe matrix to operate on.
nThe order of the ILU decomposition.
wThe relaxation factor.

Constructor.

Parameters
AThe matrix to operate on.
configurationParameterTree containing preconditioner parameters.
ParameterTree Key Meaning
iterations The number of iterations to perform
relaxation The relaxation factor

See ISTL_Factory for the ParameterTree layout and examples.

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.

Note
if a preconditioner is copied (e.g. for a second thread) again the pre() method has to be called to ensure proper memory mangement.
X x(0.0);
Y b = ...; // rhs
Preconditioner<X,Y> prec(...);
prec.pre(x,b); // prepare the preconditioner
prec.apply(x,b); // can be called multiple times now...
prec.post(x); // cleanup internal state
Parameters
xThe left hand side of the equation.
bThe right hand side of the equation.

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.

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.

Richardson preconditioner.

Multiply simply by a constant.

Template Parameters
XType of the update
YType of the defect

Member Typedef Documentation

◆ domain_type

template<class M , class X , class Y , int l = 1>
typedef X Dune::Richardson< M, X, Y, l >::domain_type

The domain type of the preconditioner.

◆ field_type

template<class M , class X , class Y , int l = 1>
typedef X::field_type Dune::Richardson< M, X, Y, l >::field_type

The field type of the preconditioner.

◆ range_type

template<class M , class X , class Y , int l = 1>
typedef Y Dune::Richardson< M, X, Y, l >::range_type

The range type of the preconditioner.

◆ scalar_field_type

template<class M , class X , class Y , int l = 1>
typedef Simd::Scalar<field_type> Dune::Richardson< M, X, Y, l >::scalar_field_type

scalar type underlying the field_type

Constructor & Destructor Documentation

◆ Richardson() [1/2]

template<class M , class X , class Y , int l = 1>
Dune::Richardson< M, X, Y, l >::Richardson ( scalar_field_type  w = 1.0)
inline

Constructor.

Constructor gets all parameters to operate the prec.

Parameters
wThe relaxation factor.

◆ Richardson() [2/2]

template<class M , class X , class Y , int l = 1>
Dune::Richardson< M, X, Y, l >::Richardson ( const ParameterTree &  configuration)
inline

Constructor.

Parameters
configurationParameterTree containing preconditioner parameters.
ParameterTree Key Meaning
relaxation The relaxation factor

See ISTL_Factory for the ParameterTree layout and examples.

Member Function Documentation

◆ apply()

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

◆ category()

template<class M , class X , class Y , int l = 1>
virtual SolverCategory::Category Dune::Richardson< M, X, Y, l >::category ( ) const
inlinevirtual

Category of the preconditioner (see SolverCategory::Category)

Implements Dune::Preconditioner< X, Y >.

◆ post()

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

◆ pre()

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

Note
if a preconditioner is copied (e.g. for a second thread) again the pre() method has to be called to ensure proper memory mangement.
X x(0.0);
Y b = ...; // rhs
Preconditioner<X,Y> prec(...);
prec.pre(x,b); // prepare the preconditioner
prec.apply(x,b); // can be called multiple times now...
prec.post(x); // cleanup internal state
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: