On Thursday September 16 2010 14:13:01 Kristian Ølgaard wrote: > On 16 September 2010 22:45, Johan Hake <johan.h...@gmail.com> wrote: > > On Thursday September 16 2010 13:33:03 Anders Logg wrote: > >> On Thu, Sep 16, 2010 at 01:27:07PM -0700, Johan Hake wrote: > >> > On Thursday September 16 2010 13:15:51 Anders Logg wrote: > >> > > 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; > >> > > >> > + > >> > > >> > Why not add a volume method while at it? Maybe we should let these be > >> > free functions as it does not always make sense to get an area or > >> > volume of a mesh? > >> > >> I don't know what the dimension-independent terms are but most people > >> would probably accept "area" as meaning the length of the boundary of > >> a 2D domain. > > > > If I had a 2D mesh and it had a method area, I would definetly think that > > it would return the area of that mesh. But that might be just me... > > Anders is talking about the area of Face/Facet of a 2D mesh which is > where this discussion originated from.
I think he here talks aout the area of a mesh. Asking for the area of a subdomain of that mesh would give me a length. I think that is strange, but I might get used to it ;) I think the area of a facet is different. Because it has codimension of -1 and follows the topology of the mesh. I realise that this argumentation can be used for a mesh too. But it would be strange to for example calculate the volume of a 2D mesh, when you actually mean the area. The area of a face is always _the_ area as it always has a topology of 2. Johan > Kristian > > > Johan > > > >> -- > >> Anders > > > > _______________________________________________ > > Mailing list: https://launchpad.net/~dolfin > > Post to : dolfin@lists.launchpad.net > > Unsubscribe : https://launchpad.net/~dolfin > > More help : https://help.launchpad.net/ListHelp _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
