[petsc-users] DMCreateGlobalVector and DMGetGlobalVector

[bichinhoverde]

Ok, but from a PETSc user perspective, what is the difference between
create and get?

When should I use get and when should I use create?

Can I call create several times to create several vectors? Is it the same
as creating one and then duplicating?

Can I call get several times to get several vectors? Is it the same as
getting one and then duplicating?

If I replace all gets with creates, or all creates with gets in my code,
what will change?




On Wed, Feb 4, 2015 at 5:16 AM, Jed Brown <jed at jedbrown.org> wrote:

> bichinhoverde <bichinhoverde at spwinternet.com.br> writes:
>
> > Hi. I have some questions.
> >
> > What is the difference between DMCreateGlobalVector and DMGetGlobalVector
> > (and the local counterparts)?
>
> Create creates a vector that the caller owns.  Get merely gets access to
> a vector from a managed pool (creating it if necessary), to be returned
> via DMRestoreGlobalVector().
>
> > What happens when one calls SNESSolve with NULL for the solution vector,
> as
> > in src/snes/examples/tutorials/ex7.c:158? SNESSolve(snes,NULL,NULL);
>
> A vector is created automatically.  You can get access to it with
> SNESGetSolution.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20150204/0eef96d6/attachment-0001.html>