GAMMASPHERE ROOT sorter GSSort
Presorting data with GSSort
Since GSSort knows how to read the GS data as well as external data,
it might be useful to presort data with the utility. Even perhaps
use the gating capabilities of GSSort to determine what to write
to the skimmed data files, besides just modifying the data format.
It is possible to do that using the Userxxxx.h files.
Below is an example that presorts your data into a very
simple format -- which you might use as a starting point for
your own skimming/presorting.