dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Mon, Jun 30, 2008 at 11:44:40AM +0200, Dag Lindbo wrote:
> Anders Logg wrote:
> > On Tue, Jun 17, 2008 at 10:52:06PM +0200, Dag Lindbo wrote:
> >> Hello again!
> >>
> >> Is it correct that Periodic BCs won't work for vector-valued systems?
> >> There is a comment to suggest this in PeriodicBC.cpp. Is there a
> >> reasonable workaround for the needy?
> >>
> >> /Dag
> > 
> > I don't know of an easy workaround.
> > 
> > But maybe you can take a look at the code in PeriodicBC.cpp to see if
> > it's possible to understand what it does and then extend it? I guess
> > the extension will be nontrivial, but the code is fairly well
> > documented so it should not be impossible.
> 
> Sorry for the basic question, but I'm struggling to figure out the role
> SubSystems play in PeriodicBCs.
> 
> E.g. on a Taylor-Hood element, SubSystem(1) corresponds to pressure - a
> scalar. I expected that it would be possible to apply the PBC to this
> subsystem. But if I do
> PeriodicBC bc(mesh, sub_domain, SubSystem(1)),
> and try to apply it I still get an abort that there are "more than one
> dof associated with coordinate. Did you forget to specify the subsystem?".
> 
> I would greatly appreciate if someone could help to clarify this.
> 
> /Dag

Is this still an issue?

-- 
Anders