[petsc-dev] [petsc-users] VECMPICUSP with ghosted vector

[Matthew Knepley]

On Mon, Feb 6, 2012 at 12:47 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> On Mon, Feb 6, 2012 at 21:42, Matthew Knepley <knepley at gmail.com> wrote:
>
>> I don't like this because it would mean calling VecSetUp() all over the
>> place. Couldn't the ghosting flag be on the same
>> level as the sizes?
>>
>
> Maybe VecSetUp() is wrong because that would imply collective. This memory
> allocation is simple and need not be collective.
>
> Ghosting information is an array, so placing it in VecSetSizes() would
> seem unnatural to me. I wouldn't really want
> VecSetGhosts(Vec,PetscInt,const PetscInt*) to be order-dependent with
> respect to VecSetType(), but maybe the VecSetUp() would be too messy.
>

I needed to be more specific. I think VecSetSizes(local, global, ghost)
would work. Then VecSetGhostIndices() can be called anytime,
and even remapped.

   Matt

-- 
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
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