template<class M, class X, class Y, int l = 1>
class Dune::SeqJac< M, X, Y, l >
The sequential jacobian preconditioner.
Wraps the naked ISTL generic block Jacobi preconditioner into the solver framework.
- Template Parameters
-
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::SeqJac< 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>
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
-
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::SeqJac< M, X, Y, l >::pre |
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X & |
x, |
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Y & |
b |
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) |
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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 = ...;
prec.pre(x,b);
prec.apply(x,b);
prec.post(x);
Base class for matrix free definition of preconditioners.
Definition: preconditioner.hh:32
- Parameters
-
x | The left hand side of the equation. |
b | The right hand side of the equation. |
Implements Dune::Preconditioner< X, Y >.