For each data table in the OPUS file (i.e. "ScSm"), there exists
a "Data Paramater" table, with three important values:
* FXV (First X Value?)
* LXV (Last X Value?)
* NPT (Number of PoinTs?)
These can generate spaced frequencies corresponding to values in
"ScSm". NPT is usually less than the length of "ScSm".
This program groups data together only if FXV, LXV, and NPT are
EXACTLY EQUAL across files. FXV and LXV are floating point numbers
so it is possible that there may be some variance across files.
Each group lumps together data with the same field value (taken from
the filename) for further processing.