Re: [Libmesh-devel] RB EIM & ParallelMesh

[David K. <dkn...@se...>]

On 01/10/2014 02:09 AM, Roy Stogner wrote:
>
> On Thu, 9 Jan 2014, Francesco Ballarin wrote:
>
>> In particular, at line 346
>> of src/reduced_basis/rb_eim_construction.C, the optimal_elem_id is
>> broadcast among the processors, in order for the optimal element to
>> be retrieved at line 356. However, when working in parallel on a
>> ParallelMesh, the element may not be a local one, causing the
>> assertion at line 318 of src/mesh/parallel_mesh.C to fail.
>
> David, this is the same place I'm seeing a failure in
> reduced_basis_ex4.
>
>> I think that a copy of the optimal element should be broadcast
>> between all the processors, possibly using a procedure similar to
>> the one in MeshSerializer (only for the optimal element, not for the
>> entire mesh), but my expertise with the ParallelMesh class is not
>> sufficient for me to implement a bugfix on my own.
>
>> Do you have any suggestions?
>
> If this is the correct bug fix, I know enough about ParallelMesh to
> come up with a patch for you to try out.  I don't know enough about RB
> to be sure it's the correct bug fix (or to test my own patch), though.

This sounds like the correct fix to me.

Regarding testing: If the parmesh version gives the same RB_sol.e as the 
serial mesh version, then it should be fine.

David