a question on MPI for DG

I have a question related to MPI mesh and DG scheme:
I need to access neighboring cell DOF information of a DG gridfunction. I noticed that the metis mesh is not overlapping, hence for a cell on the interface, it does not see its neighbor located on the other rank. How can we locate its neighbor on the other rank, and pass the information (geometric info and local DOFs) to the current rank?

Hi Guosheng,

a BilinearForm.Apply is doing the job for you. Assembling of DG matrices is not supported, HDG is fine.

In the Apply all data from the sending side is collected in the integration points on the sub-domain interfaces. Then a collective communication takes part, and finally the receiving side uses the received data for the .Other proxy.


Hi Joachim,

I see, this is how Other works!
But I would like to manually access the neighbor cell data for slope limiting purpose (done in the numpy side).
Is there a way to do so?