% @(#)overplgray.hlq	19.1 (ESO-IPG) 02/25/03 14:03:32 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      overplgray.hlq
%.AUTHOR     RHW, IPG/ESO
%.KEYWORDS   MIDAS, help files, OVERPLOT/GRAY
%.PURPOSE    On-line help file for the command: OVERPLOT/GRAY
%.VERSION    1.0  06-APR-1988 : Creation, RHW
%----------------------------------------------------------------
\se
SECTION./GRAY
\es\co
OVERPLOT/GRAY                                                06-APR-1988 RHW
\oc\su
OVERPLOT/GRAY frame [coord_str] [gray_lev] [sm_par] [gray_ness] [options]
	overplot gray scale map of 2-dim. frame with smoothing option
\us\pu
Purpose:    
            Overplot gray scale map of 2-dim. frame (with a smoothing option)
\up\sub
Subject:    
            Graphics, frames, gray scale maps
\bus\sy
Syntax:     
            OVERPLOT/GRAY frame [coord_str] gray_lev [sm_par] [gray_ness]
                          [options]
\ys\pa
            frame     = name of the frame
\ap\pa
            coord_str = area to be plotted in standard MIDAS notation
                        (see MIDAS Users Guide, Volume A, Chapter 3). Default 
                        is the manual setting done with the SET/GRAPHICS 
                        command (if present), or the whole area.
\ap\pa
            gray_lev  = gray levels; in case of a continuous gray scale
                        plot two values are required (cnt1,cnt2); in case of
                        stepwise increment of the gray scale plot input can
                        be given as \\
                        cstart:cend:cincr or cnt1,cnt2,cnt3 or
                        any combination of these two possibilities separated
                        by a comma; default is 0.0,1.0 for a continous gray
                        scale
\ap\pa
            sm_par    = smoothing parameter i.e. box width in pixels;
                        default is 1
\ap\pa
            gray_ness = grayness parameter between 0.0 and 1.0; the value 1
                        gives the maximum blackness; 0 means white;
                        default is 1.0
\ap\pa
            gray_opt  = plot options to be specified as option1,option2,...;
                        possible options are: LOG (logarythmicly increasing
                        grayness) or LIN (linear increasing grayness),
                        STEP (stepwise gray scales) or CONT (continously
                        increasing gray scales), NEG (change sign of data
                        points) or POS (leave signs unchanged) and ABS (take
                        absolute values)
\ap\no
Note:       
            The coordinates for the area are optional. If one specifies a "?",
            the area taken will be for the manual frame settings for the x-
            and y-axis. If a "C" is given, the window is selected interactively
            on the display screen using the cursor facilities. The cursor will
            be set on automatically, if it is not already. To pick up the
            coordinates, switch the cursors ON and press ENTER. To exit,
            switch the cursors OFF and press ENTER.
\\
             After the overplot the last (over)plotted data set is the active
             one and subsequent commands will work on these data.
\on\see
See also:
            PLOT/GRAY, SHOW/GRAPHICS, SET/GRAPHICS, PLOT/AXES, 
            PLOT/CONTOUR, OVERPLOT/CONTOUR, PLOT/VECTOR, OVERPLOT/VECTOR
\ees\exs
Examples:
\ex
            PLOT/GRAY spiral [@281,@281:@320,@320] ? 1,5
            OVERPLOT/GRAY spiral [@281,@281:@320,@320] 1:5 3 1. ABS,LOG
\xe\ex
            OVERPLOT/GRAY spiral [@281,@281:@320,@320] ? 1:5:0.5 ? .75 STEP
\xe \sxe
