[yt-dev] strict and unstrict regions, periodic regions

[Matthew Turk]

HI all,

Can someone remind me why we need the strict and unstrict region
objects?  The strict ones select by cell center, the unstrict by any
intersection.  I seem to recall a concrete use case but I can't dredge
it up.

Additionally, if we are actually checking for periodicity, it seems to
me we have no need for non-periodic regions, right?  We just coalesce
into a single rectangular prism object that, if appropriate for the
simulation, wraps around?

-Matt