Richard.Schwartz@gsfc.nasa.gov,  13 Aug. 1997

The SPEX package provides a uniform interface suitable for the X-ray spectral analysis
of a number of solar (or other) instruments in the X and Gamma Ray energy ranges.  The
package is suitable for any datastream which can be placed in the form of response
vs interval where the response is usually a counting rate (spectrum) and the interval
is normally an accumulation over time.  Together with an algorithm which can be used to
relate a model input spectrum to the observed response, generally a response matrix,
the dataset is amenable to analysis with this package.   Currently the data from a number of instruments
and missions have file readers, database algorithms, and matrix reader/generators that
are included within the SPEX package.  These are from SMM, HXRBS, GRS Gamma, GRS X1, GRS X2,
from Yohkoh, HXT, HXS, GRS, SXT, from CGRO, BATSE SPEC, BATSE LAD, from WIND, TGRS, the
HIREX balloon borne Ge detector, and the PIN on NEAR.   The author welcomes contributions
from other users for incorporation into the SPEX package but cannot guarantee future
compatibility with the current implementation.  There are aspects of the procedures'
argument passing that are not elegant and many aspects of this and the variables
in spex_commons.pro can be expected to change over the next few years.  However, you can
expect that the functionality of a routine like spex_current which extracts variables
from the common block will be preserved even if the variables are extracted from
something else.  The author provides this package as is without any guarantees but in the 
hope that it can provide a basic interface into many solar xray spectrometer data sets from 
the past and far into the future.