dolfin team mailing list archive

[Bartosz Sawicki <sawickib@xxxxxxxxxxxxx>]

Jehanzeb Hameed wrote:
> Thanks. I had one more question regarding...

Go ahead ! :)

> > Subdomain identifiers can be stored in different ways, as a separate
> > MeshFunction, or in the MeshData structure.
>
> If subdomain identifiers are stored in MeshData structure (as opposed
> to having a  MeshFunction "material indicators"), will they be
> transformed when the mesh is refined?  I looked at
> LocalMeshRefinement::transformMeshData(), but couldnt figure this
> thing out.

Mesh object contains MeshData, which is container for many 
MeshFunctions, std::vectors, and std::maps. All of them are identified 
by name, which is simple text string.

If you create MeshFunction and store it in MeshData using name "material 
indicators", then it will be automatically updated after refinement.


> For storing the subdomain identifiers, should the array be named
> "material indicators", in which case dolfin will automatically make a
> mesh function out of it?

Yes, but it has to be MeshFunction object, which is something different 
than array.

Take a look on documentation for Mesh, MeshData, MeshFunction. it should 
help you to understand what are the relations between those classes.
You can easy browse code documentation using:
http://www.fenics.org/pub/documents/dolfin/dolfin-progr-reference/classes.html

regrds.


> Thanks,
> -Jehanzeb
>
> On Thu, Jun 11, 2009 at 11:55 AM, Bartosz Sawicki<sawickib@xxxxxxxxxxxxx> wrote:
> > Jehanzeb Hameed wrote:
> > > Hello,
> > >
> > > I am new to Dolfin, and was wondering how subdomains are supported as
> > > regards to mesh reading and refinement. In my case, I will have a
> > > mesh, with 2 subdomains. Each cell has an identifier indicating which
> > > domain it belongs to. Looking at the examples, it seems I will need to
> > > store domain identifiers in a separate xml file. Is that correct?
> > Subdomain identifiers can be stored in different ways, as a separate
> > MeshFunction, or in the MeshData structure.
> > I prefer MeshData, because it is directly included in the Mesh object.
> > You can also store boundary indicators using MeshData structure, see
> > demo/pde/bcs.
> >
> > > With regard to mesh refinement, I assume I will be able to define
> > > subdomains for each domain based on cell identifiers. Now, when I
> > > refine the mesh, will the subdomains also be updated (i.e. will dolfin
> > > know what domain the new cells belong to) ?
> > If you name your MeshFunction "material indicators" it will be transformed
> > to follow refined mesh. Arrays which store boundary indicators will be
> > updated too.
> > See LocalMeshRefinement::transformMeshData()
> >
> > > Also, is there a way to read archives of this list?
> > Yes, there is http://www.fenics.org/pipermail/dolfin-dev/
> >
> > regrds.
> > BArtek
> >
> >
> > > Thanks,
> > > -Jehanzeb
> > > _______________________________________________
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> > > DOLFIN-dev@xxxxxxxxxx
> > > http://www.fenics.org/mailman/listinfo/dolfin-dev