;+
; NAME plot_fcorona
;
; FUNCTION	Plot F-corona function.
;
; EXTERNALS	fcorona.pro
;
; AUTHOR	Andrew L. Stanger   HAO/NCAR   3 November 2006
;-

PRO plot_fcorona

nx = 480
ny = 480
fc = FLTARR (nx, ny)

WINDOW, xsize=nx, ysize=ny, retain=2
red   = bytarr (256)
green = bytarr (256)
blue  = bytarr (256)
lct, 'bwcp.lut'
tvlct, red, green, blue, /get           ; Read color table into arrays.

;--- Get stray light for each height.

xcen = nx * 0.5 - 1.0
ycen = ny * 0.5 - 1.0
pixrs = nx / 8.0
dmin =  10
dmax = -10

FOR iy = 0, ny-1 DO	$
BEGIN
   y = float (iy)
   FOR ix = 0, nx-1 DO	$
   BEGIN
      x = float (ix)
      ierr = rcoord (radius, angle, x, y, -1, 0.0, xcen, ycen, pixrs)
;      if (ix EQ iy) THEN PRINT, 'ix/iy: ', ix, $
;      ' radius: ', radius, ' angle: ', angle
      fc [ix, iy] = skylab_fcorona (radius, angle)
;      if (ix EQ iy) THEN PRINT, 'fc: ', fc [ix, iy]
      if (fc [ix, iy] LT 0.0) THEN fc [ix, iy] = 0.0
      if (radius LT 1.0) THEN fc [ix, iy] = 0.0
      if (dmin GT fc [ix, iy]) then dmin = fc [ix, iy]
      if (dmax LT fc [ix, iy]) then dmax = fc [ix, iy]
   END
END

PRINT, 'dmin/dmax: ', dmin, dmax

;--- Display image.

slope = 250 / (dmax - dmin)
offset = dmin
fc_byte = fc * slope + offset

;fc_byte = BYTSCL (fc, min=dmin, max=dmax, top=249)
TVSCL, fc_byte
XYOUTS, 10, 10, 'SMM C/P F-CORONA MODEL', color=255, /DEVICE

FOR iy = 0, ny-1 DO	$
BEGIN
   FOR ix = 0, nx-1 DO	$
   BEGIN
;      if (ix EQ iy) THEN PRINT, 'ix/iy: ', ix, ' fc_byte: ', fc_byte [ix, iy]
   END
END


;PLOT, fc_byte [*, 240]

;--- Write image to a GIF file.

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

END