dolfin team mailing list archive

["Johan Hake" <hake@xxxxxxxxx>]

> 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<jhameed2@xxxxxxxxxxxx>
> 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<jhameed2@xxxxxxxxxxxx>
>> 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 user manual seems outdated.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<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
>>>>> _______________________________________________
>>>>> DOLFIN-dev mailing list
>>>>> DOLFIN-dev@xxxxxxxxxx
>>>>> http://www.fenics.org/mailman/listinfo/dolfin-dev
>>>>
>>>>
>>>
>>
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