On Fri, Oct 20, 2017 at 11:38 AM, John Peterson <jwpeter...@gmail.com>
wrote:
>
>
> On Fri, Oct 20, 2017 at 9:19 AM, David Knezevic <
> david.kneze...@akselos.com> wrote:
>
>> I'm using ExodusII_IO::copy_elemental_solution to copy element data to a
>> new System object, and this works fine in serial using code like the below:
>>
>> ----------------------------------------------
>>
>> Mesh mesh(comm);
>> ExodusII_IO exo_io(mesh);
>>
>> if (comm.rank() == 0)
>> {
>> exo_io.read(path_to_mesh_file);
>> }
>> MeshCommunication().broadcast(mesh);
>>
>> mesh.prepare_for_use();
>>
>> EquationSystems es(mesh);
>> ExplicitSystem& materials_system =
>> es->add_system<ExplicitSystem> ("data");
>> materials_system.add_variable ("data", CONSTANT, MONOMIAL);
>> es->init();
>>
>> exo_io.copy_elemental_solution(es, "data", "data");
>>
>> ----------------------------------------------
>>
>>
>> However, in parallel I hit the error "ERROR, ExodusII file must be opened
>> for reading before copying an elemental solution!" at the start of
>> copy_elemental_solution.
>>
>> As far as I know (e.g. based on namebased_io.C) we should only call
>> "read" on proc 0, so I don't see how to make this work in parallel, since
>> in that case exo_io is only "opened for reading" on proc 0.
>>
>> Does anyone have any suggestions on this? (John, I gather that you were
>> the author of most of the ExodusII reader stuff, so I thought you might
>> know the answer?)
>>
>
> Hmm... I think copy_elemental_solution() is only designed to work in
> serial, so could we just guard the parts the parts of that function that
> read from the file in "if (rank==0)"?
>
> In addition, we would only error out if the file is not open for reading
> on proc 0...
>
OK, that makes sense. I think we could just wrap the whole method (up to
solution->close) in "if (rank==0)", and remove the "if" around
system.solution->set so that all values are set on proc 0 and then
communicated when we close the vector. Do you agree?
David
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