----- file created by makedoc on: Tue Apr  1 15:29:54 2008
----- Documentation for /scisoft/xop2.3/extensions/shadowvui/src/lib/plot3.pro -----

 NAME:
	PLOT3
 PURPOSE:
	Plot a 3-dimensional plot/histo of a Shadow file
 CATEGORY:
	SHADOW's utilities.
 CALLING SEQUENCE:
	plot3,shadow_in,col1,col2,keyword_parameters
 INPUTS:
	shadow_in     an IDL structure with SHADOW data
	col1    column of x-axis
	col2    column of y-axis
 OPTIONAL OUTPUTS:
       hz,hx,hy    named variables with the surface (hz) and two arrays
                   with the x and y arrays (hx and hy)
               ( this option permits you the reuse of the surface generated 
               by PLOT3 for further manipulation, eg. IDL> surface,hz,hx,hy)
 KEYWORD PARAMETERS:
	XRANGE = [ min_x,max_x ]
	YRANGE = [ min_y,max_y ]
	XYRANGE = [ min,max ] (sets XRANGE=YRANGE)
	NOLOST = consider losses
		0 all rays (default option)
		1 exclude losses;
	NBINSX = number of bins in x (def=30);
	NBINSY = number of bins in y (def=30);
       REF = include reflectivity
               0 no (default)
               1 yes (A**2 as weight=column 23)
               n (21<n<34, n=column to weight (see PLOTXY for col description))

       HISTO= (removed option)
               
       NLEVELS = number of levels for the contour plot (default=10).
       TITLE   = a chain with the title

	Any other keyword is passed to surface or/and countour procedures.
 OUTPUTS:
	a graphic, and an IDL structure with the data (optional).
 COMMON BLOCKS:
	None.
 SIDE EFFECTS:
	None.
 RESTRICTIONS:
	None.
 PROCEDURE:
       Similar to Plotxy
 MODIFICATION HISTORY:
	M. Sanchez del Rio. ESRF. Grenoble, Feb 1992
	1-Sep-1992 Change input types.
	98-06-17 srio@esrf.fr almost rewritten. Added _EXTRA kw.
	2007-06-25 srio@esrf.eu makes histograms with hist_nd2,
		removed /histo option.

