% @(#)integrelli.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:18:47 
\se 
SECTION./SURFPHOT
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INTEGRATE/ELLIPS                                               29-Apr-1991 RHW
\oc\su
INTEGRATE/ELLIPS frame [ellips_par] [flag]
	integrate pixel intensities within ellipse in 2-dim. image
\us\pu
Purpose:      Integrate pixel intensities within ellipse in 2-D image
\up\sy                                                                         
Syntax:       INTEGRATE/ELLIPS frame [ellips_param] [flag]
\ys\pa 
              frame =      input image frame 
\ap\pa  
              ellips_par = ellipse parameters: center X, center Y, semi-major 
                           diameter, semi-minor diameter, position angle 
                           (degrees, 0 on x-axis, incr towards the y-axis)
                           Default are the values used in the previous run.
\ap\pa
              flag =       0 or 1. With a 1 the ellipse parameters are obtained
                           from the descriptor ELLPAR of the input frame;
                           default is 0.
\ap\no
Note:         The program does a simultaneous search for points within a 
              slightly larger ellipse, determines the differential increase 
              in pixel area, ellipse area and flux. A linear interpolation 
              is applied to get flux from pixels covering same total area 
              (approx same region) as the nominal ellipse.
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              The result is stored in the descriptor ELLPAR(1) to ELLPAR(6).
              The flux (integral over all pixel values is stored in the 
              descriptor ELLPAR(6)
\on\exs 
Examples:                                                                      
\ex
              INTEGRATE/ELLIPS myframe 250,312,50,30,45
\xe \sxe