% @(#)extracctra.hlq	19.1 (ESO-IPG) 02/25/03 14:03:19 
%++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
%.COPYRIGHT  (c)  1990 European Southern Observatory
%.IDENT      extracctra.hlq
%.AUTHOR     KB, IPG/ESO
%.KEYWORDS   MIDAS, help files, EXTRACT/CTRACE
%.PURPOSE    On-line help file for the command: EXTRACT/CTRACE
%.VERSION    1.0  05-FEB-1990 : Creation, KB
%.VERSION    1.1  18-APR-1991 : Update, KB
%----------------------------------------------------------------
\se
SECTION./CTRA
\es\co
EXTRACT/CTRACE						02-FEB-2002  KB
\oc\su
EXTRACT/CTRACE [step] [frame] [plot_flag] [zw_option]
	extract a column from displayed image
\us\pu
Purpose: 
          Extract interactively a column from a displayed image.
\up\sy
Syntax:  
          EXTRACT/CTRACE [step] [frame] [plot_flag] [zw_option]
\ys\pa
          step = stepsize along the traced column;
               defaulted to stepsize in y of displayed image 
\ap\pa
          frame = name for result frame; defaulted to 'column.bdf'.
\ap\pa
          plot_flag = DRAW, PLOT or NONE; defaulted to DRAW;
               if set to DRAW, a plot of the extracted column is displayed in
               the overlay channel each time the ENTER button is pushed;
               if set to PLOT, a plot of the extracted column is displayed on
               the graphics terminal (graphics window) each time the ENTER
               button is pushed.
\ap\pa
          zw_option = zoom_window_flag,zoom;
              zoom_window_flag = W for zoom_window, N for none,
              zoom = initial zoom factor; defaulted to N,4;
              only applicable to X11 window displays!
\ap\sa
See also:
          EXTRACT/TRACE, EXTRACT/RTRACE, EXTRACT/ROTATED
          VIEW/IMAGE, GET/CURSOR
\as\no
Note: 
             Use the mouse to move cursor #0 to mark the column in the
	  currently displayed image. 
	  To extract the chosen column and exit, press the EXIT button
	  (the button to the right of the ENTER button). The start/end pixels
	  of the original frame where the column was extracted are saved in
	  int. descr. START_END_TRACEPIX.
             With the zoom window option you first select a subwindow in the
          main display window. Then move the mouse into the zoom window
          and choose the column trace. Push Enter to extract the column and
	  draw the full column vector in the main display window. Press Exit
	  to go back to the main window and choose another subwindow there
	  or press Exit to leave the command.
             All the additional functionality which comes with the zoom
          window option (see e.g. VIEW/IMAGE) is also available.
             The parameter 'frame' may be set to "+" also, which means that
          no frame is extracted (only useful with plot_flag = DRAW or PLOT).
\on\exs
Examples:
\ex
          EXTRACT/CTRACE ? gato
            Extract column of displayed frame and store in 1-dim frame
            `gato.bdf' and show the profile, each time the ENTER button
            is pressed. Use stepsize in y-direction of displayed frame.
\xe\ex
          EXTRACT/CTRACE 1.05 
            Extract 1-dim frame `column.bdf' from displayed frame 
            and use stepsize = 1.05 in the sampling of the column.
\xe\ex
          EXTRACT/CTRACE ? mosca plot w
            Extract column from displayed frame and store in frame `mosca.bdf'.
            Choose the column in the zoom window and plot the profile in the
            graphics window each time you press Enter (in the zoom window).
            If no graphics and/or zoom window exist, they are created with
            default sizes.
\xe \sxe

