Dune Core Modules (2.9.0)
Richardson preconditioner. More...
#include <dune/istl/preconditioners.hh>
Public Types  
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 Simd::Scalar< field_type >  scalar_field_type 
scalar type underlying the field_type  
typedef FieldTraits< scalar_field_type >::real_type  real_field_type 
real scalar type underlying the field_type  
Public Member Functions  
Richardson (real_field_type w=1.0)  
Constructor. More...  
Richardson (const ParameterTree &configuration)  
Constructor. More...  
virtual void  pre ([[maybe_unused]] X &x, [[maybe_unused]] Y &b) 
Prepare the preconditioner. More...  
virtual void  apply (X &v, const Y &d) 
Apply the precondioner. More...  
virtual void  post ([[maybe_unused]] X &x) 
Clean up. More...  
virtual SolverCategory::Category  category () const 
Category of the preconditioner (see SolverCategory::Category)  
virtual void  pre (X &x, Y &b)=0 
Prepare the preconditioner. More...  
virtual void  post (X &x)=0 
Clean up. More...  
Detailed Description
template<class X, class Y>
class Dune::Richardson< X, Y >
Richardson preconditioner.
Multiply simply by a constant.
 Template Parameters

X Type of the update Y Type of the defect
Constructor & Destructor Documentation
◆ Richardson() [1/2]

inline 
Constructor.
Constructor gets all parameters to operate the prec.
 Parameters

w The relaxation factor.
◆ Richardson() [2/2]

inline 
Constructor.
 Parameters

configuration ParameterTree containing preconditioner parameters.
ParameterTree Key  Meaning 

relaxation  The relaxation factor. default=1.0 
See ISTL_Factory for the ParameterTree layout and examples.
Member Function Documentation
◆ apply()

inlinevirtual 
Apply the precondioner.
Apply one step of the preconditioner to the system A(v)=d. On entry v=0 and d=bA(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 >.
◆ post() [1/2]

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.
◆ post() [2/2]

pure virtualinherited 
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.
Implemented in Dune::BlockPreconditioner< X, Y, C, P >, Dune::NonoverlappingBlockPreconditioner< C, P >, Dune::InverseOperator2Preconditioner< O, c >, Dune::Amg::KAMG< M, X, S, PI, K, A >, Dune::Amg::FastAMG< M, X, PI, A >, Dune::Amg::AMG< M, X, S, PI, A >, Dune::Amg::AMG< M, X, S, SequentialInformation, std::allocator< X > >, and Dune::Amg::AMG< Operator, X, Smoother >.
◆ pre() [1/2]

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.
 Parameters

x The left hand side of the equation. b The right hand side of the equation.
◆ pre() [2/2]

pure virtualinherited 
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.
 Parameters

x The left hand side of the equation. b The right hand side of the equation.
Implemented in Dune::BlockPreconditioner< X, Y, C, P >, Dune::NonoverlappingBlockPreconditioner< C, P >, Dune::InverseOperator2Preconditioner< O, c >, Dune::Amg::KAMG< M, X, S, PI, K, A >, Dune::Amg::FastAMG< M, X, PI, A >, Dune::Amg::AMG< M, X, S, PI, A >, Dune::Amg::AMG< M, X, S, SequentialInformation, std::allocator< X > >, and Dune::Amg::AMG< Operator, X, Smoother >.
The documentation for this class was generated from the following file:
 dune/istl/preconditioners.hh