template<class M, class X, class Y, int l = 1>
class Dune::SeqSOR< M, X, Y, l >
Sequential SOR preconditioner.
Wraps the naked ISTL generic SOR preconditioner into the solver framework.
- Template Parameters
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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 |
template<class M , class X , class Y , int l = 1>
virtual void Dune::SeqSOR< M, X, Y, l >::apply |
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X & |
v, |
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const Y & |
d |
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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.
- Parameters
-
[out] | v | The update to be computed |
| d | The current defect. |
Implements Dune::Preconditioner< X, Y >.
template<class M , class X , class Y , int l = 1>
template<bool forward>
void Dune::SeqSOR< M, X, Y, l >::apply |
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X & |
v, |
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const Y & |
d |
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inlinevirtual |
Apply the preconditioner in a special direction.
The template parameter forward indications the direction the smoother is applied. If true The application is started at the lowest index in the vector v, if false at the highest index of vector v.
Implements Dune::Preconditioner< X, Y >.
template<class M , class X , class Y , int l = 1>
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< X, Y >.
template<class M , class X , class Y , int l = 1>
virtual void Dune::SeqSOR< M, X, Y, l >::pre |
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X & |
x, |
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Y & |
b |
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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.
- 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.
X x(0.0);
Y b = ...;
Preconditioner<X,Y> prec(...);
prec.pre(x,b);
prec.apply(x,b);
prec.post(x);
- Parameters
-
x | The left hand side of the equation. |
b | The right hand side of the equation. |
Implements Dune::Preconditioner< X, Y >.