% @(#)extracline.hlq	17.1.1.1 (ESO-IPG) 01/25/02 17:43:34 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      extracline.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, EXTRACT/LINE
%.PURPOSE    On-line help file for the command: EXTRACT/LINE
%.VERSION    1.0  14-FEB-1985 : Creation, KB
%----------------------------------------------------------------
\se
SECTION./LINE
\es\co
EXTRACT/LINE				                   20-MAY-1997   KB
\oc\su
EXTRACT/LINE out = in[..] step
	extract a 1-dim line from a 2-dim frame
\us\pu
Purpose:    
            Extract a 1-dim line from a 2-dim frame.
\up\sy
Syntax:  
            EXTRACT/LINE out = in intval [step]
\ys\pa
            out = resulting 1-dim. frame
\ap\pa
            in = input frame
\ap\pa
            intval = [xll,yll:xur,yur] defines "lower left" and "upper right"
               corners in the input frame, the surrounding square brackets
               ([ and ]) are necessary;
\\
               the resulting frame will be the diagonal from corner to corner
\ap\pa
            step = optional stepsize along the line, 
\\
               default is the stepsize in x (or y) of the input frame
\ap\no
Note:       
            xll, xur, yll, yur can be in any of the following formats:
\\
            a number, to indicate real world coords. 
\\
            a number preceded by @, to indicate a pixel no. 
\\
            the chars. "<" and ">", to indicate start or end pixel.
\\
            Caution, if the name of the result frame is equal to the name of
            the input frame, this frame will be overwritten!
\\
            For backwards compatibility also the previous syntax of this
            command: EXTRACT/LINE out = inintval [step] (i.e. input file and
            coord interval glued together in one parameter) is supported.
\on\see
See also:   
            EXTRACT/IMAGE, EXTRACT/TRACE
\ees\exs
Examples:
\ex
            EXTRACT/LINE vaca = toro [2.15,1.0:12,20.2] 3.4
              Extract a line starting at world coords (2.15,1.0) and ending at 
              w. coords (12,20.2) of image `toro.bdf', pixels are sampled using 
              a stepsize of 3.4 along that line. Store resulting line in 1-dim
              image `vaca.bdf'.
\xe\ex
            EXTRACT/LINE vaca = toro [600,@2:800,@5] 
              As above but use world coords as well as pixel coords to define
              the start and end of the line. Pixels are sampled using either
              the x- or y-step of `toro.bdf' depending upon if the ramp in the
              x- or y-direction is less steep.
\xe\ex
            EXTRACT/LINE vaca = toro[600,@2:800,@5] 
              As above using "old" syntax.
\xe \sxe