> I think I got it working. I used the version of eval which passes in > Data arguement.
Good choice! I do not think we have a demo defining such a function. However we do have an example that is similar to your case, presented in the docstring of Function in the PyDOLFIN interface. Look at example: 3. Complex user-defined JIT-compiled functions Maybe not the most obvious place to look at :P Cheers! Johan > On Sun, Jun 14, 2009 at 6:45 PM, Jehanzeb Hameed<jhame...@illinois.edu> > wrote: >> I want to do evaluate a form like this, arising from poisson equation >> with variable coefficient: >> >> k * dot(grad(v),grad(u))*dx >> >> >> To do this, I define k as >> >> cellElement = FiniteElement("Discontinuous Lagrange", "triangle", 0) >> >> k = Function(cellElement) >> >> Now I want to define values of k dependent on material type of cell. >> This is the link I cant figure out how to do. >> >> -Jehanzeb >> >> On Sun, Jun 14, 2009 at 5:50 PM, Jehanzeb Hameed<jhame...@illinois.edu> >> wrote: >>> I am still struggling with this.... >>> >>> I am trying to store subdomain identifiers in meshdata object, so that >>> they get updated when the mesh is refined. To do this, I have a file, >>> mesh.xml. In that file, there is a tag named "data". The "data" tag >>> has a child "array" with name = "material indicators". So, now when I >>> create mesh, will my meshdata have this array? >>> >>> And how do I create cell dependent functions. The example in Dolfin >>> user manual seems outdated. I think I need to use UFCfunction, but >>> what do I pass as Function arguement to its constructor (if >>> UFCfunction is indeed the correct way to go). >>> >>> -Jehanzeb >>> >>> On Thu, Jun 11, 2009 at 11:55 AM, Bartosz >>> Sawicki<sawic...@iem.pw.edu.pl> 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 >>>>> _______________________________________________ >>>>> DOLFIN-dev mailing list >>>>> DOLFIN-dev@fenics.org >>>>> http://www.fenics.org/mailman/listinfo/dolfin-dev >>>> >>>> >>> >> > _______________________________________________ > DOLFIN-dev mailing list > DOLFIN-dev@fenics.org > http://www.fenics.org/mailman/listinfo/dolfin-dev > _______________________________________________ DOLFIN-dev mailing list DOLFIN-dev@fenics.org http://www.fenics.org/mailman/listinfo/dolfin-dev