Dune Core Modules (2.4.2)
Block parallel preconditioner. More...
#include <dune/istl/schwarz.hh>
Public Types  
enum  { category =SolverCategory::overlapping } 
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.  
typedef C  communication_type 
The type of the communication object.. More...  
Public Member Functions  
BlockPreconditioner (T &p, 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 preconditioner. More...  
template<bool forward>  
void  apply (X &v, const Y &d) 
Apply one step of the preconditioner to the system A(v)=d. More...  
virtual void  post (X &x) 
Clean up. More...  
Detailed Description
class Dune::BlockPreconditioner< X, Y, C, T >
Block parallel preconditioner.
This is essentially a wrapper that takes a sequential preconditioner. In each step the sequential preconditioner is applied and then all owner data points are updated on all other processes.
 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. The type of the sequential preconditioner to use for approximately solving the local matrix block consisting of unknowns owned by the process. Has to implement the Preconditioner interface.
Member Typedef Documentation
◆ communication_type
typedef C Dune::BlockPreconditioner< X, Y, C, T >::communication_type 
The type of the communication object..
This must either be OwnerOverlapCopyCommunication or a type implementing the same interface.
◆ domain_type
typedef X Dune::BlockPreconditioner< X, Y, C, T >::domain_type 
The domain type of the preconditioner.
E.g. BlockVector or another type fulfilling the ISTL vector interface.
◆ range_type
typedef Y Dune::BlockPreconditioner< X, Y, C, T >::range_type 
The range type of the preconditioner.
E.g. BlockVector or another type fulfilling the ISTL vector interface.
Member Enumeration Documentation
◆ anonymous enum
anonymous enum 
Constructor & Destructor Documentation
◆ BlockPreconditioner()

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

p The sequential preconditioner. c The communication object for syncing overlap and copy data points. (E.~g. OwnerOverlapCopyCommunication )
Member Function Documentation
◆ apply() [1/2]

inlinevirtual 
Apply the preconditioner.
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 >.
◆ apply() [2/2]

inlinevirtual 
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()

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()

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 >.
The documentation for this class was generated from the following file:
 dune/istl/schwarz.hh