[dune-pdelab] Jacobian_volume vs jacobian_apply_volume

[René Heß]

Hi Amir,


the jacobian methods will assemble the Jacobian matrix J. This matrix
will be used by the linear solvers to solve your system.

Some solvers only need J to calculate the application of J to a vector
x. This means the solvers only needs to be able to compute Jx for a
given vector x. With the jacobian apply methods it is possible to
calculate this application of the Jacobian without ever assembling J.

This can be used to implement matrix-free solvers that could be faster
for certain cases. In your case you can ignore this issue and you won't
need the jacobian_apply methods (or if the compiler complains you can
just use the numerical methods, they won't be used anyway).


Best regards,
René


Amir Peiraviminaei <apminaei at gmail.com> writes:

> Hi everyone,
> I'm using pdelab for a FV scheme and tutorial 02 as an example. So far I
> have used only numerical jacobian, Now I want to implement analytical
> jacobian myself, my question is
> 1. What is the difference between jacobian_volume and jacobian_apply_volume?
> (tutorial 02 uses both)
>
> Best
> Amir
> _______________________________________________
> dune-pdelab mailing list
> dune-pdelab at lists.dune-project.org
> https://lists.dune-project.org/mailman/listinfo/dune-pdelab
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