PCApply_Shell & ghosts...

[Matthew Knepley]

PETSc knows nothing about your domain, so it can't know what you might want
"ghosted". I think the thing to do is use a VecScatter to map the input Vec to a
ghosted Vec (called a local vector in DA language).

  Matt

On Wed, Aug 13, 2008 at 3:41 PM, Eric Chamberland
<Eric.Chamberland at giref.ulaval.ca> wrote:
> Hi,
>
> we are using PETSc in our code and we have a problem with, I think, the
> ghosted values that we expect.
>
> We developed our own pre-conditioner, and try to use it in a parallel
> environment.  With other precondtioners (PETSc built-in), everything works
> fine.  But with our home-made one, here is the problem that we have:
>
> When PCApply_Shell give use the vectors, there are no "ghost" values in
> them...  In our code, we expect to always have these values...
>
> Not having the ghosts in the vectors passed by PCApply_shell, is that a
> normal behavior?
>
> Thanks for the attention,
>
> Eric
>
>



-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
-- Norbert Wiener