UFC

Mesh entity indices are ambigious

Bug #1061721 reported by Garth Wells on 2012-10-04
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
UFC
New
Undecided
Unassigned

Bug Description

UFC is ambiguous with respect to local or global mesh entity indices. To make DOLFIN 'work' in parallel a confusing mix of local and global indices are used. This issue should be clarified.

As far as UFC is concerned, shouldn't 'local' refer to local wrt a
cell and 'global' refer to global wrt the mesh known to UFC which is
the mesh on a local processor?

Anything global beyond that should be handled by DOLFIN.

--
Anders

On Thu, Oct 04, 2012 at 04:21:08PM -0000, Garth Wells wrote:
> Public bug reported:
>
> UFC is ambiguous with respect to local or global mesh entity indices. To
> make DOLFIN 'work' in parallel a confusing mix of local and global
> indices are used. This issue should be clarified.
>
> ** Affects: ufc
> Importance: Undecided
> Status: New
>

Garth Wells (garth-wells) wrote :

On Thu, Oct 4, 2012 at 6:16 PM, Anders Logg <email address hidden> wrote:
> As far as UFC is concerned, shouldn't 'local' refer to local wrt a
> cell and 'global' refer to global wrt the mesh known to UFC which is
> the mesh on a local processor?
>

What we have now is a confusing mixture of local and global, and UFC
says nothing about local and global.

Garth

> Anything global beyond that should be handled by DOLFIN.
>
> --
> Anders
>
>
> On Thu, Oct 04, 2012 at 04:21:08PM -0000, Garth Wells wrote:
>> Public bug reported:
>>
>> UFC is ambiguous with respect to local or global mesh entity indices. To
>> make DOLFIN 'work' in parallel a confusing mix of local and global
>> indices are used. This issue should be clarified.
>>
>> ** Affects: ufc
>> Importance: Undecided
>> Status: New
>>
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1061721
>
> Title:
> Mesh entity indices are ambigious
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/ufc/+bug/1061721/+subscriptions

Anders Logg (logg) wrote :

On Thu, Oct 04, 2012 at 05:35:49PM -0000, Garth Wells wrote:
> On Thu, Oct 4, 2012 at 6:16 PM, Anders Logg <email address hidden> wrote:
> > As far as UFC is concerned, shouldn't 'local' refer to local wrt a
> > cell and 'global' refer to global wrt the mesh known to UFC which is
> > the mesh on a local processor?
> >
>
> What we have now is a confusing mixture of local and global, and UFC
> says nothing about local and global.

Is it just the terminology that is confusing?

I think UFC is clear in that local means cell and global means mesh
(the part of the mesh it knows which would be the local mesh).

--
Anders

Garth Wells (garth-wells) wrote :

OK, UFC may be clear but then DOLFIN is wrong. DOLFI N provides a local/global option for UFCCell, and DOLFIN breaks if the wrong option is used. There are demos that use ufc::cell::index to index into a MeshFunction, in which case it must be the local index, but UFC says that it's the global index.

To post a comment you must log in.
This report contains Public information  Edit
Everyone can see this information.

Other bug subscribers