Re: [Libmesh-users] Variable groups to use blocked matrix (*BAIJ)

[Paul T. B. <ptb...@gm...>]

The last time I talked to @benkirk (which was a long time ago...) he'd
indicated they used this feature very regularly. It may have been for only
a single variable group, but I can't say for sure. We definitely need to
exercise this more I think (and I'm also guilty of not really doing it when
really I should be).

On Thu, May 10, 2018 at 9:44 AM, David Knezevic <dav...@ak...>
wrote:

> On Thu, May 10, 2018 at 9:38 AM, Roy Stogner <roy...@ic...>
> wrote:
>
> >
> > On Wed, 9 May 2018, John Peterson wrote:
> >
> > On Wed, May 9, 2018 at 11:56 AM, Linda G <li...@na...> wrote:
> >>
> >> Dear Libmesh Users,
> >>>
> >>> We are trying to figure out how to set up a Stabilized NS FEM
> formulation
> >>> to work
> >>> in a blocked matrix fashion. After reading the documentation we
> realized
> >>> that this boils down to define a
> >>> variable group, but we could not find any example (even the Elasticity
> >>> ones) that uses the
> >>> block matrix (*BAIJ) feature.
> >>> Please remember that our formulation is stabilized, so we are using
> P1P1
> >>> and P2P2 for velocity and pressure.
> >>> Is the function to define variables groups a member of System class or
> >>> DofMap class?
> >>> Please if anyone has a working example, or teach us how to do it, we
> >>> really
> >>> appreciate.
> >>>
> >>>
> >> If I understand correctly, this should happen automatically if you have
> a
> >> System with 1 variable group that contains more than 1 var, provided
> that
> >> you configure libmesh with --enable-blocked-storage. The default is
> >> --disable-blocked-storage since I believe we ran into some issues while
> >> using this option in the past.
> >>
> >
> > https://github.com/libMesh/libmesh/issues/703 is the only concrete
> > issue I can find, thanks to SourceForge mailing list changes breaking
> > old archive links.
> >
> > We should probably track this down soon so we can at least upgrade
> > blocked-storage from "enable only explicitly" to "enable with
> > --enable-everything".  I haven't been testing --enable-blocked-storage
> > for a long time so it may have regressed even further.
> > ---
> > Roy
>
>
>
> Should we re-open #703 then? I agree that we never got to the bottom of
> what was going on there, we just avoided the issue by disabling some
> examples.
>
> David
> ------------------------------------------------------------
> ------------------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, Slashdot.org! http://sdm.link/slashdot
> _______________________________________________
> Libmesh-users mailing list
> Lib...@li...
> https://lists.sourceforge.net/lists/listinfo/libmesh-users
>