ZOOM

        [GTVL\]ZOOM [Argument(s)] [/NEW] [/CURRENT] [/REGION]

    ZOOM can be used to modify the viewing window of the current plot.   The
    zooming does not affect the plot, but only the way it is displayed.
      - ZOOM X1 X2 Y1 Y2 Defines the viewing window by its corners
      - ZOOM OFF Turns off zooming, i.e. defines the viewing  window  to  be
        the plot page
      - ZOOM REFRESH Redraw the current plot (useful after CLEAR SEGMENT)

    Without arguments ZOOM calls the cursor to define a new viewing  window.
    This  new  window will be defined by its center (at the cursor position)
    and a zooming factor (by steps of 1.414) :
       Z    Increase the zooming factor
       -    Decrease it
       B    Display the viewing window boundaries
    These commands do not produce effective zooming, press the space bar
    to do it. Additional commands :
       A    Clear alphanumeric screen
       0    Display the whole plot page (ZOOM OFF).
            <Space> returns to previous zooming factor.
       E    Exits from the routine.
    For X11 displays, you may use the mouse buttons for the commands Z (left
    mouse  button),  <Space>  (middle  mouse  button),  and  E  (right mouse
    button).

    Option /NEW and /CURRENT can be used to  specified  whether  the  zoomed
    area appears in the special zoom window (/NEW) or in the original window
    (/CURRENT). Default behaviour is specified by  CHANGE  ZOOM  NEW|CURRENT
    command.