A general discussion of the McTiernan spectral fitting programs is given
on page 
in the description of fitting WBS spectra.
A routine which will do spatially resolved HXT spectra is also
available, called HXTBOX_FSP. To use this, the input index and data
structures must come from an HXI file, instead of index and data from
HDA files used by HXT_FSP. The region for the spectral fit is chosen
using the routine LCUR_IMAGE, before the time interval is chosen.
Here are some sample calls.
IDL> hxtbox_fsp, index, data, fit_pars
IDL> hxtbox_fsp, index, data, fit_pars, boxq=boxq
IDL> hxtbox_fsp, index, data, countfile = 'test.dat'
IDL> hxtbox_fsp, index, data, fit_pars, same_bx=boxq
IDL> hxtbox_fsp, index, data, fit_pars, boxq=boxq, /same_bx
where 
is an array
containing the subscripts of the chosen regions, (corresponding to the
keyword 
in LCUR_IMAGE). If 
is set, the routine will
use the array of subscripts contained in (or if is not set,
than the array in is used). Note that the final two examples
will accomplish the same thing. The output structure 
is an
array of (n_intervals 
n_boxes).