% @(#)overplline.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:47
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      overplline.hlq
%.AUTHOR     RHW, IPG/ESO
%.KEYWORDS   MIDAS, help files, OVERPLOT/LINE
%.PURPOSE    On-line help file for the command: OVERPLOT/LINE
%.VERSION    1.0  17-SEP-1988 : Creation, RHW
%----------------------------------------------------------------
\se
SECTION./LINE
\es\co
OVERPLOT/LINE                                             17-SEP-1988  RHW
\oc\su
OVERPLOT/LINE [l_type] [x_sta,y_sta[,wo|,mm|,sc|,no]] 
                       [x_end,y_end[,wo|,mm|,sc|,no]]
	overplot a line on a graphic device
\us\pu
Purpose:    
            Overplot a line on a graphics device
\up\sub
Subject:    Graphics, lines
\bus\sy
Syntax:     
            OVERPLOT/LINE [ltype] 
                     [x_sta,y_sta[,wo|,mm|,sc|,no]] 
                     [x_end,y_end[,wo|,mm|,sc|,no]]
\ys\pa
            ltype =  number: 0 -- no line at all; 
                     1 -- solid; 2 -- dotted; 3 -- short dash; 
                     4 -- dash - dot; 5 -- long dash;  
                     6 -- dash - dot - dot; default is 1
\ap\pa
            x_sta,y_sta[,wo|,mm|,sc|,no] = Starting coordinate of the line or `C' 
                     for cursor input; default is `C'. Positions can be
                     given in world coordinates (,wo), in mm (,mm). in 
                     screen coordinates, or in normalized coordintes (,no).\\
                     World coordinates refer to the coordinate box of the 
                     axes, defined and plotted by either a plot command 
                     or plot/overplot axes command. The reference point 
                     (origin) for both screen coordinates and mm 
                     coordinates is the lower left corner (0,0). Screen 
                     coordinates are supported for graphics and display 
                     windows only.\\
                     By default, i.e. if no units are given, coordinates 
                     are interpreted as a world coordinates.
\\
                     In case NO coordinate pair is entered the graphics 
                     cursor will appear, allowing you to enter the begin 
                     and end points with the left mouse button. Exit with 
                     the right mouse button.
\ap\pa
            x_end,y_end[,wo|,mm|,sc|,no] = Ending coordinate of the line. 
                     For details concerning the format see above. The input 
                     is ignored in case P2 = `C', i.e. coordinate input 
                     by cursor.
\ap\no
Note:       
            The command allows to overplot a line outside the graphics frame.
            In such a case, if one wants to input start and end coordinates
            an extrapolation of the x- and/or y-axis should be applied.
\\
            The command allows you to re-iterate: as long as the exit button 
            isn't pressed you can choose another position of the line with 
            the left button.
\\
            Screen coordinates are only supported for MIDAS graphics and 
            display windows.
\on\sa
See also:   
            SET/GRAPHICS, LABEL/GRAPHICS, OVERPLOT/SYMBOL, OVERPLOT/ERROR,
            OVERPLOT/GRID
\as\exs
Examples:
\ex
            PLOT/ROW myframe @125 @100,@440
            OVERPLOT/LINE 3 ?
            Plot a line of a frame and overplot a line in line type 3 using 
            the graphic cursor.
\xe\ex
            PLOT/ROW myframe @125 @100,@440
            OVERPLOT/LINE 6 250,50 350,50
            As in the previous example but with the start and end coordinates
            given.
\xe \sxe