PRO NPLOT,ncw
;
fname=STRING(ncw,FORMAT='(I3,"/signal.za")')
OPENR,unit,fname,/GET_LUN
READF,unit,c,r & d=FLTARR(c,r)
READF,unit,d & CLOSE,unit & FREE_LUN,unit
d=TRANSPOSE(d) & w=d(*,0)
m0=d(*,1) & sd0=d(*,2)
m57=d(*,3) & sd57=d(*,4)
mx0=MAX(m0) & mx57=MAX(m57)
nm0=m0/mx0 & nsd0=sd0/mx0
nm57=m57/mx57 & nsd57=sd57/mx57
!P.TITLE=STRING(ncw, $
         FORMAT='("Passband of ",I3," nm Filter in PoCa Optics Module")')
!X.TITLE='Wavelength ( nm )'
!Y.TITLE='Normalized Signal from Center of Illuminated Screen'
mnw=MIN(w,MAX=mxw)
PLOT,w,nm0,XRANGE=[mnw,mxw],XSTYLE=1,YRANGE=[0,MAX([nm0+nsd0,nm57+nsd57])]
ERRPLOT,w,nm0-nsd0,nm0+nsd0
OPLOT,w,nm57,LINESTYLE=2
ERRPLOT,w,nm57-nsd57,nm57+nsd57
top=!Y.CRANGE(1)                ; upper limit of Y (camera signal) axis
wrange=mxw-mnw			; length of X (wavelength) axis
; put descriptive legend on graph
PLOTS,[mnw+0.05*wrange,mnw+0.10*wrange],[0.95*top,0.95*top]
XYOUTS,mnw+0.12*wrange,0.95*top,'0 !9%!x zenith angle'
PLOTS,[mnw+0.05*wrange,mnw+0.1*wrange],[0.9*top,0.9*top],linestyle=2
XYOUTS,mnw+0.12*wrange,0.9*top,'57 !9%!x zenith angle'
; make a list of all 'old' in-optics filter calibration data files
pbold=FINDFILE('/wesson/user/steele/PAC/filter/calib/*/*.spl',COUNT=nold)
PRINT,'You can overplot one of the following old passband curves for comparison.'
FOR i=0,nold-1 DO PRINT,STRING(i,pbold(i),FORMAT='(I1,2X,A)')
rfilter,wold,sold               ; read in the selected data file
nsold=sold/MAX(sold)		; normalize the old data to the new data
OPLOT,wold,nsold,PSYM=4         ; and overplot it for comparison
PLOTS,[mnw+0.05*wrange,mnw+0.10*wrange],[0.85*top,0.85*top],PSYM=4
XYOUTS,mnw+0.12*wrange,0.85*top,'0 !9%!x z. a. (old)'   ; update legend
RETURN
END