[dune-pdelab] parallel pdelab for simple problem

[Eike Mueller]

Dear dune-pdelab list,

I'm trying to adapt my serial code to run in parallel. Basically, I took 
  example 4 from the pdelab howto (I modified the local operator 
slightly) and use a 3d YaspGrid. I then modified my code according to 
section 3.3, i.e. I changed the constraints, use a parallel grid (again, 
YaspGrid with overlap 0) and changed to solver backend to one of the 
non-overlapping backends. However, the results are wrong, if I run with 
8 cores then the solution is discontinuous across the faces that 
separate the eight domains. Also, alpha_skeleton of the local operator 
does not seem to get called for the faces between the domains. Is there 
an example of how to modify the local operator to make it parallel? Or 
do I have to choose a non-zero overlap in this case?

Thank you very much,

Eike