;+
; :Description:
;   Read in the lab-measured UVIS EUV or FUV sensitivity values.
;
; Outputs:
;   wcal: wavelength
;   ucal: sensitivity at each wavelength
;   ucalerror: uncertainty in sensitivity
;
; Keyword Parameters:
;   CHANNEL: either 'EUV' or 'FUV'
;   WDIR: path to data files
;   
; Restrictions:
;   Requires these data files:
;     EUV_1999_Lab_Cal.dat
;     FUV_1999_Lab_Cal.dat
; 
; Modification history:
;   June 8, 2015: Accommodate dimensional difference between EUV and FUV file contents, GMH
;-
pro get_uvis_lab_sensitivity, wcal, ucal, ucalerror, channel=channel, wdir=wdir
  ;
  ; read sensitivity data
  ;
  ; this is the full-slit, low-resolution, monochromatic extended source sensitivity measured in the laboratory in 1997, and updated in 1999
  ; S = 1.e9 / 4./ !pi * Atelescope * Aslit / focal_length^2 * QE_UVIS
  ; where:
  ;  Atelescope = telescope area (4 cm^2)
  ;  Aslit = the full area of the entrance slit (0.15mm * 6mm)
  ;  focal_length = telescope focal length (100mm)
  ;  QE_UVIS = the QE of the instrument (I believe this includes detector QE and transmission/reflection/grating losses)
  ;  S has units of (counts/second) / (kilorayleigh)
  ;
  if keyword_set(wdir) eq 0 then wdir=''
  get_lun,uu
  filename_lab_cal = wdir + channel + '_1999_Lab_Cal.dat'  ; 'EUV_1999_Lab_Cal.dat' or 'FUV_1999_Lab_Cal.dat'
  case channel of
    'EUV': begin
      dat_dim = 14*3
      wcal_dim = 14
    end
    'FUV': begin
      dat_dim = 13*6
      wcal_dim = 26
    end    
  endcase
  openr,uu,filename_lab_cal
  x=' '
  readf,uu,x
  dat=fltarr(dat_dim)
  readf,uu,dat
  free_lun,uu
  wcal=fltarr(wcal_dim)
  ucalerror=wcal
  ucal=wcal
  for k=0,12 do wcal(k)=dat(k*6)
  for k=0,12 do ucal(k)=dat(k*6+1)
  for k=0,12 do ucalerror(k)=dat(k*6+2)
  for k=13,25 do wcal(k)=dat((k-13)*6+3)
  for k=13,25 do ucal(k)=dat((k-13)*6+4)
  for k=13,25 do ucalerror(k)=dat((k-13)*6+5)
end