dune-istl
2.2.0
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Sequential Gauss Seidel preconditioner. More...
#include <dune/istl/preconditioners.hh>
Public Types | |
enum | { category = SolverCategory::sequential } |
typedef M | matrix_type |
The matrix type the preconditioner is for. | |
typedef X | domain_type |
The domain type of the preconditioner. | |
typedef Y | range_type |
The range type of the preconditioner. | |
typedef X::field_type | field_type |
The field type of the preconditioner. |
Public Member Functions | |
SeqGS (const M &A, int n, field_type w) | |
Constructor. | |
virtual void | pre (X &x, Y &b) |
Prepare the preconditioner. | |
virtual void | apply (X &v, const Y &d) |
Apply the preconditioner. | |
virtual void | post (X &x) |
Clean up. |
Sequential Gauss Seidel preconditioner.
Wraps the naked ISTL generic block Gauss-Seidel preconditioner into the solver framework.
M | The matrix type to operate on |
X | Type of the update |
Y | Type of the defect |
l | The block level to invert. Default is 1 |
typedef X Dune::SeqGS< M, X, Y, l >::domain_type |
The domain type of the preconditioner.
typedef X::field_type Dune::SeqGS< M, X, Y, l >::field_type |
The field type of the preconditioner.
typedef M Dune::SeqGS< M, X, Y, l >::matrix_type |
The matrix type the preconditioner is for.
typedef Y Dune::SeqGS< M, X, Y, l >::range_type |
The range type of the preconditioner.
anonymous enum |
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inline |
Constructor.
Constructor gets all parameters to operate the prec.
A | The matrix to operate on. |
n | The number of iterations to perform. |
w | The relaxation factor. |
References Dune::CheckIfDiagonalPresent< Matrix, blocklevel, l >::check().
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inlinevirtual |
Apply the preconditioner.
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 where
is the approximate inverse of the operator
characterizing the preconditioner.
[out] | v | The update to be computed |
d | The current defect. |
Implements Dune::Preconditioner< X, Y >.
References Dune::dbgs().
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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.
x | The right hand side of the equation. |
Implements Dune::Preconditioner< X, Y >.
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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.
x | The left hand side of the equation. |
b | The right hand side of the equation. |
Implements Dune::Preconditioner< X, Y >.