[lammps-users] arbitrary group support for dcd and xtc dumps. need testers.

hi everybody,

i've just added support for groups other than "all"
to dcd and xtc format dumps in LAMMPS. since this
touches code in dump.cpp and was a bit tricky to implement
in a reasonably way in parallel without blowing up the
memory usage per cpu, i'd like to have it tested by
some of you before i send it to steve for inclusion.
if you want to try it out, just drop me a note and
i'll send you the modified files.

another questions:
with the added code it would also be easily possible
to have .xyz output that is always sorted by atom id,
so that the same atom is always in the same line.
would there be some interest in that as well?