[petsc-dev] VecNestSetSubVec for VecNest.

[Vijay S. Mahadevan]

> I would not try to simultaneously change the distribution of the Vec. That's
> what VecScatter is for. VecConvert() would keep the same distribution and
> give you back a semantically identical vector of a different type.

Well, I implied changing the parallel layout because of the code I've
seen in say libMesh and other packages using PETSc. Their idea of
localize() is often to convert a MPI vector to a locally serial vector
with/without ghost nodes. I see your point on using VecScatter and so
VECSEQ can still be disallowed but some form of Ghosted parallel
vector conversion would still be useful.

On Mon, Oct 17, 2011 at 9:00 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
> On Mon, Oct 17, 2011 at 20:55, Vijay S. Mahadevan <vijay.m at gmail.com> wrote:
>>
>> Actually, that is quite consistent in philosophy to the merge
>> operation I'm trying to perform. SEQ->MPI might still be an invalid
>> operation for Vec though. Perhaps with a PETSC_DECIDE for local, it
>> still could be relevant ? You can definitely specialize this for
>> MPI->SEQ and Nest Vectors with a new VecReuse enum with relevant
>> names.
>
> I would not try to simultaneously change the distribution of the Vec. That's
> what VecScatter is for. VecConvert() would keep the same distribution and
> give you back a semantically identical vector of a different type.