Filter out explosion frames in narupa.mdanalysis.universe

[jbarnoud]

When reading a trajectory in an MDAnalysis universe, frames describing an explosion can be problematic as they can contain NaNs. This would break some analyses, but most importantly, it crashes VMD when the trajectory is converted to a format that VMD can read. A solution is to exclude the frames with NaNs from the Universe.

[jbarnoud]

After further investigation, an exploding trajectory can also break the libxdr, preventing writing an xtc file. This does not require any non-finite value, instead, it seems that large displacements are the issue causing the libxdr to complain:

Internal overflow compressing coordinates.