DUNE PDELab (2.8)
#include <dune/istl/paamg/twolevelmethod.hh>
Public Types | |
typedef CSP | CoarseLevelSolverPolicy |
The type of the policy for constructing the coarse level solver. | |
typedef CoarseLevelSolverPolicy::CoarseLevelSolver | CoarseLevelSolver |
The type of the coarse level solver. | |
typedef FO | FineOperatorType |
The linear operator of the finel level system. Has to be derived from AssembledLinearOperator. | |
typedef FineOperatorType::range_type | FineRangeType |
The type of the range of the fine level operator. | |
typedef FineOperatorType::domain_type | FineDomainType |
The type of the domain of the fine level operator. | |
typedef CSP::Operator | CoarseOperatorType |
The linear operator of the finel level system. Has to be derived from AssembledLinearOperator. | |
typedef CoarseOperatorType::range_type | CoarseRangeType |
The type of the range of the coarse level operator. | |
typedef CoarseOperatorType::domain_type | CoarseDomainType |
The type of the domain of the coarse level operator. | |
typedef S | SmootherType |
The type of the fine level smoother. | |
typedef FO::domain_type | domain_type |
The domain type of the preconditioner. | |
typedef FO::range_type | range_type |
The range type of the preconditioner. | |
typedef X::field_type | field_type |
The field type of the preconditioner. | |
Public Member Functions | |
TwoLevelMethod (const FineOperatorType &op, std::shared_ptr< SmootherType > smoother, const LevelTransferPolicy< FineOperatorType, CoarseOperatorType > &policy, CoarseLevelSolverPolicy &coarsePolicy, std::size_t preSteps=1, std::size_t postSteps=1) | |
Constructs a two level method. More... | |
virtual SolverCategory::Category | category () const |
Category of the preconditioner (see SolverCategory::Category) | |
virtual void | pre (FO::domain_type &x, FO::range_type &b)=0 |
Prepare the preconditioner. More... | |
virtual void | apply (FO::domain_type &v, const FO::range_type &d)=0 |
Apply one step of the preconditioner to the system A(v)=d. More... | |
virtual void | post (FO::domain_type &x)=0 |
Clean up. More... | |
Detailed Description
class Dune::Amg::TwoLevelMethod< FO, CSP, S >
- Template Parameters
-
FO The type of the fine level linear operator. CSP The type of the coarse level solver policy. S The type of the fine level smoother used.
Constructor & Destructor Documentation
◆ TwoLevelMethod()
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inline |
Constructs a two level method.
- Template Parameters
-
CoarseSolverPolicy The policy for constructing the coarse solver, e.g. OneStepAMGCoarseSolverPolicy
- Parameters
-
op The fine level operator. smoother The fine level smoother. policy The level transfer policy. coarsePolicy The policy for constructing the coarse level solver. preSteps The number of smoothing steps to apply before the coarse level correction. preSteps The number of smoothing steps to apply after the coarse level correction.
References Dune::Amg::LevelTransferPolicy< FO, CO >::clone(), and Dune::Amg::LevelTransferPolicy< FO, CO >::createCoarseLevelSystem().
Member Function Documentation
◆ apply()
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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.
◆ post()
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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.
◆ 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 mangement.
- Parameters
-
x The left hand side of the equation. b The right hand side of the equation.
The documentation for this class was generated from the following file:
- dune/istl/paamg/twolevelmethod.hh