[Dune] boundary id

[Christian Engwer]

Hi all,

On Tue, Dec 12, 2006 at 10:26:19AM +0100, Oswald Benedikt wrote:
> Hi Dune Team, with respect to id's, may they be associated with
> boundary faces or subdomains, from a practical point of view, it is very
> useful to have these; now that the concept of subdomains is served
> by the LGM flavour in the UG grid manager, it would also be very
> useful to be able to access these in a Dune based application.

I think we all agree that one needs some kind of boundary
identitfication. But up to now Done lacks a proper domain
interface. Boundary Ids are only a small part of the whole
problem. Last year we decided to introduce the boundaryId as a
intermediat interface that would allow to somehow identify the
boundary parts, and to postpone a proper boundary representation until
we discuss a domain interface.

> For example, we here have a number of grids in the LGM format,
> used previously in pure UG applications, which we would like
> to use, with full subdomain information, in a Dune based code
> as well.

LGM is a very new feature in UGGrid and everything but tested. It is
disabled by default and I would be surprised if it is officially
supported in the 1.0 release.

> Therefore, to have this information would be highly welcome,
> if feasible with reasonable effort, already in the upcoming
> release 1.0.

Having boundaryIds would be nice, but one could not only rely on
LGM. I have no idea how much work these changes require. Perhaps
Oliver can comment on this part.

Christian