;+
; vignet.c
; * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
; Determines SMM C/P vignetting correction for radius r (Rsun units).
; * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
; Andrew L. Stanger   HAO/NCAR   SMM C/P
; 1 March 1984
; 17 June 1998: Conversion from C to IDL.
; * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
;-

FUNCTION vignet, r

;float	r;			/* Radius in Rsun units. */


;#define NTAB 87

;float v;

;--- Radial values in units of r/rsun corresponding to stray light table.

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]

;--- Vignetting ratios as a fraction of transmission from 0.0 Rsun
;    out to 8.4 Rsun in increments of 0.1 solar radius.
;
;    vignetting estimate :  Dale Gary   7 July 1982   (smvig2).

vigtab =								    $
     [1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, $
      1.000, 1.000, 1.000, 1.000, 1.000, 35.34, 19.31, 12.53, 9.083, 7.003, $
      5.656, 4.706, 4.034, 3.519, 3.113, 2.789, 2.536, 2.327, 2.160, 2.017, $
      1.895, 1.787, 1.685, 1.590, 1.498, 1.419, 1.347, 1.281, 1.222, 1.174, $
      1.135, 1.099, 1.069, 1.044, 1.023, 1.009, 1.001, 1.000, 1.000, 1.000, $
      1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, $
      1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, $
      1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000, $
      1.000, 1.000, 1.000, 1.000, 1.000, 1.000, 1.000]

;* ------------------------------------------------------------------------- */
   size_vigtab = size (vigtab)
   NTAB = size_vigtab (1)

   v = lint (r, rtab, vigtab, NTAB)

   RETURN, v
END