  Connecting cosmological simulations to real-world observational programs is
often complicated by a mismatch in geometry: while surveys often cover highly
irregular cosmological volumes, simulations are customarily performed in a
periodic cube. We describe a technique to remap this cube into elongated
box-like shapes that are more useful for many applications. The remappings are
one-to-one, volume-preserving, keep local structures intact, and involve
minimal computational overhead.
