dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, Sep 16, 2010 at 01:10:55PM -0700, Johan Hake wrote:
> On Thursday September 16 2010 13:03:44 Anders Logg wrote:
> > On Thu, Sep 16, 2010 at 12:51:28PM -0700, Johan Hake wrote:
> > > On Thursday September 16 2010 12:27:57 Anders Logg wrote:
> > > > On Thu, Sep 16, 2010 at 12:23:48PM -0700, Johan Hake wrote:
> > > > > On Thursday September 16 2010 11:46:02 Anders Logg wrote:
> > > > > > On Thu, Sep 16, 2010 at 11:24:34AM -0700, Johan Hake wrote:
> > > > > > > Hello!
> > > > > > >
> > > > > > > I added the method area to the Face class. I guess a Face is
> > > > > > > always a triangle so it should be safe.
> > > > > >
> > > > > > Yes.
> > > > >
> > > > > ok
> > > > >
> > > > > > > There might be other methods that can be usefull like
> > > > > > > normal? Others?
> > > > > >
> > > > > > Probably but can't think of any more right now.
> > > > > >
> > > > > > > Should we do the same for Facet, but then check for topological
> > > > > > > dimension before making the computation, a la the generalized
> > > > > > > volume in CellTypes?
> > > > > >
> > > > > > Facet should have normal but not area.
> > > > >
> > > > > I wont add these now. I first thought they were straight forward, but
> > > > > all kindoff R^1, R^2, R^3 stuff needs to be checked for. Leave it
> > > > > for now...
> > > > >
> > > > > Added a blueprint!
> > > >
> > > > I thought I already did that. We have Cell.normal() which should
> > > > handle that.
> > >
> > > That just calls normal of TriangleCell or TetrahedronCell. TriangleCell
> > > only returns a normal for topological dimension 2.
> >
> > Isn't that enough? What else do you need?
>
> For a Face I need to check if it is in R^2 or R^3.
>
> > > It is really not difficult, it just took some more time than I
> > > anticipated, and I do not need the feature. I just needed area :)
> >
> > Oh so you didn't need anything else. ;-)
>
> Nope! Not for the moment.
>
> But now it is at least straight forward to iterate over faces of a 3D mesh and
> calculate the area of a certain boundary domain given by a MeshFunction :)

Perhaps we could have

  double::Mesh::area(const FacetFunction& boundary_markers, uint boundary) const;

--
Anders