Periodic boundary conditions

[boriskaus]

It would be great to be able to specify periodic boundary conditions

[ranocha]

I can only second that! I wanted to set up a simple prototype for a colleague who needs periodic BCs. I followed the tutorial and was stuck when trying to switch the BCs.

[utkinis]

Should be relatively simple to add, as there is already some groundwork in place. Periodicity is the property of the grid (not documented though since unfinished), and selecting which fields should be copied over will be specified through the exchange keyword on kernel launch or exchange! function, which now are only used for MPI exchange.