DUNE-FEM (unstable)
an algebraic multigrid method using a Krylov-cycle. More...
#include <dune/istl/paamg/kamg.hh>
Public Types | |
typedef AMG< M, X, S, PI, A > | Amg |
The type of the underlying AMG. | |
typedef K | KrylovSolver |
The type of the Krylov solver for the cycle. | |
typedef Amg::OperatorHierarchy | OperatorHierarchy |
The type of the hierarchy of operators. | |
typedef Amg::CoarseSolver | CoarseSolver |
The type of the coarse solver. | |
typedef Amg::ParallelInformation | ParallelInformation |
the type of the parallelinformation to use. | |
typedef Amg::SmootherArgs | SmootherArgs |
The type of the arguments for construction of the smoothers. | |
typedef Amg::Operator | Operator |
the type of the lineatr operator. | |
typedef Amg::Domain | Domain |
the type of the domain. | |
typedef Amg::Range | Range |
The type of the range. | |
typedef Amg::ParallelInformationHierarchy | ParallelInformationHierarchy |
The type of the hierarchy of parallel information. | |
typedef Amg::ScalarProduct | ScalarProduct |
The type of the scalar product. | |
typedef X | domain_type |
The domain type of the preconditioner. | |
typedef X | range_type |
The range type of the preconditioner. | |
typedef X::field_type | field_type |
The field type of the preconditioner. | |
Public Member Functions | |
virtual SolverCategory::Category | category () const |
Category of the preconditioner (see SolverCategory::Category) | |
KAMG (OperatorHierarchy &matrices, CoarseSolver &coarseSolver, const SmootherArgs &smootherArgs, const Parameters &parms, std::size_t maxLevelKrylovSteps=3, double minDefectReduction=1e-1) | |
Construct a new amg with a specific coarse solver. More... | |
template<class C > | |
KAMG (const Operator &fineOperator, const C &criterion, const SmootherArgs &smootherArgs=SmootherArgs(), std::size_t maxLevelKrylovSteps=3, double minDefectReduction=1e-1, const ParallelInformation &pinfo=ParallelInformation()) | |
Construct an AMG with an inexact coarse solver based on the smoother. More... | |
void | pre (Domain &x, Range &b) |
Prepare the preconditioner. More... | |
void | post (Domain &x) |
Clean up. More... | |
void | apply (Domain &v, const Range &d) |
Apply one step of the preconditioner to the system A(v)=d. More... | |
virtual void | pre (X &x, X &b)=0 |
Prepare the preconditioner. More... | |
virtual void | apply (X &v, const X &d)=0 |
Apply one step of the preconditioner to the system A(v)=d. More... | |
Detailed Description
class Dune::Amg::KAMG< M, X, S, PI, K, A >
an algebraic multigrid method using a Krylov-cycle.
The implementation is based on the paper [Notay and Vassilevski, 2007]
- Template Parameters
-
M The type of the linear operator. X The type of the range and domain. PI The parallel information object. Use SequentialInformation (default) for a sequential AMG, OwnerOverlapCopyCommunication for the parallel case. K The type of the Krylov method to use for the cycle. A The type of the allocator to use.
Member Function Documentation
◆ apply()
|
pure virtualinherited |
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.
Implemented in Dune::SeqOverlappingSchwarz< M, X, TM, TD, TA >, Dune::SeqOverlappingSchwarz< M, X, TM, TS, TA >, Dune::SeqOverlappingSchwarz< M, X, TM, TD, TA >, and Dune::SeqOverlappingSchwarz< M, X, TM, TS, TA >.
◆ pre()
|
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 management.
- Parameters
-
x The left hand side of the equation. b The right hand side of the equation.
Implemented in Dune::SeqOverlappingSchwarz< M, X, TM, TD, TA >, and Dune::SeqOverlappingSchwarz< M, X, TM, TS, TA >.
The documentation for this class was generated from the following files: