% @(#)overplcont.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:47 
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%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      overplcont.hlq
%.AUTHOR     RHW, IPG/ESO
%.KEYWORDS   MIDAS, help files, OVERPLOT/CONTOUR
%.PURPOSE    On-line help file for the command: OVERPLOT/CONTOUR
%.VERSION    1.0  09-JUN-1987 : Creation, RHW
%----------------------------------------------------------------
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SECTION./CONT
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OVERPLOT/CONTOUR                                             09-JUN-1987 RHW
\oc\su
OVERPLOT/CONTOUR frame [coord_str] [contours] [sm_par]
	overplot contour map of 2-dim. frame with smoothing option
\us\pu
Purpose:    
            Overplot contour map of 2-dim. frame with a smoothing option
\up\sub
Subject:    
            Graphics, frames, contour maps
\bus\sy
Syntax:     
            OVERPLOT/CONTOUR frame [coord_str] [contours] [c_type] [sm_par]
\ys\pa
            frame     = name of the frame
\ap\pa
            coord_str = area to be overplotted 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
            contours  = contour values; input can be given as
                        cstart:cend:cincr or cnt1,cnt2,cnt3..., or any
                        combination of these two possibilities separated
                        by a comma. (Default 1.0)
\ap\pa
            c_type =    NEG, ODD, or LTYPE: determines the line type(s) used.
                        NEG will draw negative contours dashed and positive
                        ones solid; ODD will draw odd contours dashed and even
                        ones solid; If LTYPE is specified contours will be
                        drawn with the line type specified with SET/GRAPHICS.
                        Default is NEG
\ap\pa
             sm_par =   smoothing parameter i.e. the number of pixels "around"
                        the central pixel which define the neighbourhood of
                        that pixel. 
\\
                        Total number of pixels is then: (2*sm_par + 1)**2 
                        Only integer numbers are allowed. Default is 0
\ap\no
Note:
            The coordinates for the area are optional. If one specifies a "?",
            and the manual frame setting(s) for the x- and y-axis are used
            these settings will be used; else the whole area will be taken.
            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.
\\
            For XWindows use the mouse to move the cursor, the leftmost
            mouse button or the RETURN key is the ENTER button, the
            second left mouse button serves as EXIT button.  The cursor cross
            may not be visible at first. Move the mouse to the lower left
            corner of the graphics window to grab the cursor.
\\
            The size of the plot area (area within the rectangular cursor) can
            be be changed by using the arrow keys on the keyboard (XWindows).
\\
            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/CONTOUR, SET/GRAPHICS, ASSIGN/GRAPHICS
\ees\exs
Examples:
\ex
            PLOT/CONTOUR spiral [@281,@281:@320,@320] ? 1:5:0.25 LTYPE 3
            Make a contour plot of the frame ``spiral''. Use default scales
            and draw the contours 1, 1.25, 1.5, ...till 5. Use the line set
            by the command SET/GRAPH. Use a smoothing box of 3x3 pixels. 
\xe\ex
            OVERPLOT/CONTOUR spiral [@281,@281:@320,@320] 6,7,8 ODD 3
            Do an overplot of the same frame, however, now for the contours
            6, 7, and 8. Contours 6 and 8 will be dashed, contour 7 solid.  
\xe \sxe