adding SNESSetLinearSolve()

[Matthew Knepley]

On 10/29/07, Lisandro Dalcin <dalcinl at gmail.com> wrote:
> In practice, the only way to wrap any solver package is
> KSPPREONLY+PCSHELL. And you actually implement the linear solve in PC,
> not KSP.

I disagree here. See below.

> If PETSc internals were implemented in C++, I would simply do:
>
> MyKSP: public KSP {
> void solve(Vec b, Vec x) {
>    /* do something */
>    KSP::solve(b1,x1)
>    /* do more*/
>    KSP::solve(b2, x2)
>   /* fill result */
>   x = ...
> }
> }
>
> But with the current implementation in C, this is possible but not so
> easy to do.

Since this seems specific to this application, why not just make a custom
KSP implementation that does exactly the above. It would probably also
need a SetFromOptions() that configures the two subKSPs.

  Matt

> --
> Lisandro Dalcín
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