MatGetSubMatrix question

[Lisandro Dalcin]

On Mon, May 25, 2009 at 10:20 AM, Jed Brown <jed at 59a2.org> wrote:
>
> Is it really necessary that iscol be a sequential index set that covers
> all columns, with csize selecting the local columns?  I realize this
> might be natural/easy for AIJ formats, but it feels clumsy (not to
> mention not scalable due to the ISAllGather).
>

Your are right, this is not scalable, but...

> I'm guessing this is a relic from when IS was not a real parallel
> object.  Am I missing some deep reason for this interface, or could
> iscol be parallel and csize be dropped?
>

unless things have changed very recently (after 3.0.0 release), IS is
far from being a real parallel object.



-- 
Lisandro Dalcín
---------------
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