Dune Core Modules (2.9.0)
A parallel SSOR preconditioner. More...
#include <dune/istl/schwarz.hh>
Public Types  
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, [[maybe_unused]] Y &b) 
Prepare the preconditioner. More...  
virtual void  apply (X &v, const Y &d) 
Apply the precondtioner. 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 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.
Constructor & Destructor Documentation
◆ ParSSOR()

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()

inlinevirtual 
Apply the precondtioner.
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 >.
References Dune::bsorb(), and Dune::bsorf().
◆ 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/schwarz.hh