DUNE PDELab (git)
#include <dune/pdelab/backend/istl/seq_amg_dg_backend.hh>
Public Member Functions | |
SolverCategory::Category | category () const override |
Category of the preconditioner (see SolverCategory::Category) | |
SeqDGAMGPrec (DGMatrix &dgmatrix_, DGPrec &dgprec_, CGPrec &cgprec_, P &p_, int n1_, int n2_) | |
Constructor. More... | |
virtual void | pre (X &x, Y &b) override |
Prepare the preconditioner. More... | |
virtual void | apply (X &x, const Y &b) override |
Apply the precondioner. More... | |
virtual void | post (X &x) override |
Clean up. More... | |
Detailed Description
class Dune::PDELab::SeqDGAMGPrec< DGMatrix, DGPrec, CGPrec, P >
An ISTL preconditioner for DG based on AMG applied to CG subspace
The template parameters are: DGMatrix BCRSMatrix assembled with DG DGPrec preconditioner to be used for DG CGPrec preconditioner to be used on CG subspace P BCRSMatrix for grid transfer
Constructor & Destructor Documentation
◆ SeqDGAMGPrec()
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inline |
Constructor.
Constructor gets all parameters to operate the prec.
- Parameters
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A The matrix to operate on. n The number of iterations to perform. w The relaxation factor.
Member Function Documentation
◆ apply()
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inlineoverridevirtual |
Apply the precondioner.
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
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[out] v The update to be computed d The current defect.
Implements Dune::Preconditioner< DGPrec::domain_type, DGPrec::range_type >.
◆ post()
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inlineoverridevirtual |
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
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x The right hand side of the equation.
Implements Dune::Preconditioner< DGPrec::domain_type, DGPrec::range_type >.
◆ pre()
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inlineoverridevirtual |
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 management.
- Parameters
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x The left hand side of the equation. b The right hand side of the equation.
Implements Dune::Preconditioner< DGPrec::domain_type, DGPrec::range_type >.
The documentation for this class was generated from the following file:
- dune/pdelab/backend/istl/seq_amg_dg_backend.hh