DUNE-FEM (unstable)
Parallel algebraic multigrid based on agglomeration. More...
#include <dune/istl/paamg/amg.hh>
Public Types | |
typedef M | Operator |
The matrix operator type. | |
typedef PI | ParallelInformation |
The type of the parallel information. Either OwnerOverlapCommunication or another type describing the parallel data distribution and providing communication methods. | |
typedef MatrixHierarchy< M, ParallelInformation, A > | OperatorHierarchy |
The operator hierarchy type. | |
typedef OperatorHierarchy::ParallelInformationHierarchy | ParallelInformationHierarchy |
The parallal data distribution hierarchy type. | |
typedef X | Domain |
The domain type. | |
typedef X | Range |
The range type. | |
typedef InverseOperator< X, X > | CoarseSolver |
the type of the coarse solver. | |
typedef S | Smoother |
The type of the smoother. More... | |
typedef SmootherTraits< Smoother >::Arguments | SmootherArgs |
The argument type for the construction of the smoother. | |
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 | |
AMG (OperatorHierarchy &matrices, CoarseSolver &coarseSolver, const SmootherArgs &smootherArgs, const Parameters &parms) | |
Construct a new amg with a specific coarse solver. More... | |
template<class C > | |
AMG (const Operator &fineOperator, const C &criterion, const SmootherArgs &smootherArgs=SmootherArgs(), const ParallelInformation &pinfo=ParallelInformation()) | |
Construct an AMG with an inexact coarse solver based on the smoother. More... | |
AMG (std::shared_ptr< const Operator > fineOperator, const ParameterTree &configuration, const ParallelInformation &pinfo=ParallelInformation()) | |
Constructor an AMG via ParameterTree. More... | |
AMG (const AMG &amg) | |
Copy constructor. | |
void | pre (Domain &x, Range &b) |
Prepare the preconditioner. More... | |
void | apply (Domain &v, const Range &d) |
Apply one step of the preconditioner to the system A(v)=d. More... | |
virtual SolverCategory::Category | category () const |
Category of the preconditioner (see SolverCategory::Category) | |
void | post (Domain &x) |
Clean up. More... | |
template<class A1 > | |
void | getCoarsestAggregateNumbers (std::vector< std::size_t, A1 > &cont) |
Get the aggregate number of each unknown on the coarsest level. More... | |
void | recalculateHierarchy () |
Recalculate the matrix hierarchy. More... | |
bool | usesDirectCoarseLevelSolver () const |
Check whether the coarse solver used is a direct solver. 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::AMG< M, X, S, PI, A >
Parallel algebraic multigrid based on agglomeration.
- Template Parameters
-
M The LinearOperator type which represents the matrix X The vector type S The smoother type A An allocator for X
- Todo:
- drop the smoother template parameter and replace with dynamic construction
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()
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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 file:
- dune/istl/paamg/amg.hh