;+
; NAME plot_cpvignet
;
; FUNCTION	Plot SMM C/P Vignetting function.
;
; EXTERNALS	cpvignet.pro
;
; AUTHOR	Andrew L. Stanger   HAO/NCAR   3 November 2006
;-

PRO plot_cpvignet

rtab =								   $
      [0.00, 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, $
       1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, $
       2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 2.60, 2.70, 2.80, 2.90, $
       3.00, 3.10, 3.20, 3.30, 3.40, 3.50, 3.60, 3.70, 3.80, 3.90, $
       4.00, 4.10, 4.20, 4.30, 4.40, 4.50, 4.60, 4.70, 4.80, 4.90, $
       5.00, 5.10, 5.20, 5.30, 5.40, 5.50, 5.60, 5.70, 5.80, 5.90, $
       6.00, 6.10, 6.20, 6.30, 6.40, 6.50, 6.60, 6.70, 6.80, 6.90, $
       7.00, 7.10, 7.20, 7.30, 7.40, 7.50, 7.60, 7.70, 7.80, 7.90, $
       8.00, 8.10, 8.20, 8.30, 8.40, 8.50, 8.60]

srtab  = size (rtab)
ntab   = srtab [1]
print, 'ntab: ', ntab
vig    = FLTARR (ntab)
viginv = FLTARR (ntab)
i = 0

cfac = 0.7
IF (STRLOWCASE (!version.os) EQ 'irix')    THEN cfac = 1.4
IF (STRLOWCASE (!version.os) EQ 'sunos' )  THEN cfac = 0.7
cs = cfac * 1.0                              ; character size

WINDOW, retain=2
red   = bytarr (256)
green = bytarr (256)
blue  = bytarr (256)
lct, 'bwinv.lut'
TVLCT, red, green, blue, /get           ; Read color table into arrays.

;--- Get vignetting for each height.

FOR i = 0, ntab-1 DO	$
BEGIN
   vig [i] = cpvignet (rtab [i] * 960.0)
   PRINT, 'rtab: ', rtab [i], '   vig: ', vig [i]
END

;--- Plot C/P Vignetting.

PLOT, rtab, vig, xtitle="Radial Distance (Rsun)", $
      ytitle="Vignetting Correction", charsize=cs

XYOUTS, 0.5, 0.85, "SMM Coronagraph Vignetting", charsize=cs, /normal

;--- Save plot as a GIF file.

gif_file = "cpvignet.gif"
img_gif = TVRD ()
WRITE_GIF, gif_file, img_gif, red, green, blue
wait, 3.0

;--- Plot Inverse Vignetting.

viginv = 1.0 / vig				; Inverse Vignetting.

PLOT, rtab, viginv, xtitle="Radial Distance (Rsun)", $
      ytitle="Vignetting Attenuation", $
      yrange = [0.0, 1.2], charsize=cs

XYOUTS, 0.5, 0.85, "SMM Coronagraph Inverse Vignetting", charsize=cs, /normal

gif_file = "cpvignet_inverse.gif"
img_gif = TVRD ()
WRITE_GIF, gif_file, img_gif, red, green, blue

END