;+
; NAME:
;  rt_hitran
; PURPOSE: (one line)
;  read hitran files
; DESCRIPTION:
;  read hitran files
; CATEGORY:
;  RT
; CALLING SEQUENCE:
;  lines = rt_hitran(fn, selmin, selmax)
; INPUTS:
;  filename - hitran file
;  selmin - minimum wavenumber for selection
;  selmax - maximum wavenumber for selection
; OPTIONAL INPUT PARAMETERS:
; KEYWORD INPUT PARAMETERS:
; KEYWORD OUTPUT PARAMETERS:
; OUTPUTS:
;  structure with:
;    wav, str, wid, eng, nlines, stot, wav0, wmin, wmax 
; COMMON BLOCKS:
;  None
; SIDE EFFECTS:
; RESTRICTIONS:
;  None
; PROCEDURE:
; MODIFICATION HISTORY:
;  Written 2004 May 8, Leslie Young SwRI
;  based on hitran.f, written by Leslie Young, 1998
;-
function rt_hitran, filename, selmin, selmax
    
    lines = rd_lines(filename, 0., 0., 0., 0., selmin,selmax, 0.)
    stot = total(lines.s)
    wav0 = total(lines.s*lines.nu0)/stot
    nlines = n_elements(lines)

    hitran={ $,
     wav_name:'wavenumber of transition',wav:lines.nu0, wav_unit:'invcm',$
     str_name:'line strength', str:lines.s, str_unit:'invcm cm^2/molecule',$
     eng_name:'energy of lower state', eng:lines.E_lower, eng_unit:'invcm',$    
     wid_name:'air-broadened width at STP', wid:lines.gamma_air, wid_unit:'invcm',$        
     nlines_name:'number of lines', nlines:nlines, nlines_unit:'', $
     stot_name:'total line strength',stot:stot,stot_unit:'invcm cm^2/molecule',$
     wav0_name:'average wavenumber',wav0:wav0,wav0_unit:'invcm',$
     wmin_name:'average wavenumber',wmin:lines[0].nu0,wmin_unit:'invcm',$
     wmax_name:'average wavenumber',wmax:lines[nlines-1].nu0,wmax_unit:'invcm'$
    }

   return, hitran

end

pro rt_hitrandriver

; should be lines 9314 to 25625
    fn = '/planet/hitran96/hitran96/by_molec/06_hit96.par'
    selmin=1071.
    selmax=1544.
    h=rt_hitran(fn, selmin,selmax)

    print, h.nlines, h.stot, h.wav0
;     16311 lines read, with strength   5.28109717E-18 at   1308.78229


end