dolfin team mailing list archive

[kent-and@xxxxxxxxx]

>
>
> mspieg wrote:
>> Hi All,
>>    I think there is a bug when trying to read a MeshFunction from a file
>> that was generated on a SubMesh.  I've attached some python based on the
>> SubMesh demo, that demonstrates the problem.  I think the issue is that
>> there is an extra MeshFunction
>> embedded in a
>> SubMesh to describe the "global vertex indices" that gets read instead
>> of the intended mesh-function.
>>
>
> It might be a while before anyone gets to this. We hope to have a new,
> simple to use bug tracking system (i.e. not Bugzilla) in place soon to
> keep track of these types of issues, especially since they tend to be
> forgotten while everyone is on holiday.
>
>
>> On a related note, it's easy enough to extract a SubMesh from a larger
>> Mesh using a MeshFunction, but what is the best way to extract just the
>> piece of a discrete function on the SubMesh, when the Function is
>> originally defined for a Function Space on the larger mesh. (does this
>> make sense?)
>>
>> These issues arise from a multiphysics problem that I'm working with
>> overlapping domains  where I basically want to solve an embedded porous
>> media problem on a subdomain of a larger stokes flow (this is slightly
>> different from the fluid-structure demo where the two domains only share
>> a boundary.)
>>
>
> Kent has been working on something like this. Have you looked at
>
>    demo/function/restriction
>
> ?
>

So isn't what you want to do something like

a = stokes_problem*dx(1) + darcy_problem*dx(2)

?

This can be accomplished without using the restriction functionality, but
by using meshfunctions or subdomains to specify domain 1 and 2.

Kent