Hi all, What's the best way to handle boundary conditions? I was thinking mainly, what's the smallest signal we can send -- typically into Cython routines that might need to iterate -- that indicates, "wrap this around the edge in this dimension"? Essentially I think there are two main cases we need to consider for the purposes of what yt wants, which are: 1) Periodic along an axis 2) Non-periodic (inflow, isolated) on an axis This shows up for the plotting routines, vertex-centering of data, and a handful of other things. I'm not sure how to handle this the best. If we really have only these options (and I'm not a 100% on that) then would it work to have a simple array of axes that hangs off the hierarchy object, which is 0 for non-periodic on an axis and 1 for periodic? -Matt