WINDOW

boundaries

 There is usually at least one rectangle drawn on the monitor screen. The
 largest rectangle represents the world boundary, the maximum extent of the
 hardcopy page. A smaller, inner, rectangle, drawn with a dashed line,
 represents a sub-window within the page. These rectangles are for the user's
 reference only and will not appear on a hardcopy. These boundary rectangles
 can be turned off with the DISABLE BORDER command.

plotting_units

 Sub-windows have different plotting unit ranges than the full page. Thus,
 when a sub-window has been selected, it is possible that not all subsequent
 graphics will be contained within this window. However, commensurateness is
 always preserved within a sub-window, for example, circles, which appear as
 circles when drawn into the full page, will still be circular when drawn
 into any sub-window.

define_a_window

 Syntax: WINDOW n { lowx lowy { upx upy }}

 Window zero, the full page or world, cannot be modified. A new window can
 be defined by including the final four parameters with the command. The
 lower left corner will be (lowx,lowy) and the upper right corner will be
 (upx,upy). These four parameters should be expressed as percentages of
 the world, e.g., lowx = 50, lowy = 50 represents the centre of the world.
 If window number n is entered, but not the final four parameters, and
 that window number is undefined, then the graphics cursor will be used
 to choose the lower left and upper right corners of the new window.

NOMESSAGES

 If the \NOMESSAGES qualifier is used, then the values of the window 
 coordinates will not be displayed.

GPLOT

 Choosing a window with the WINDOW command:
 WINDOW n lowx,lowy upx,upy
 is equivalent to choosing the GPLOT window with the SET command
 SET
  %XLWIND lowx
  %YLWIND lowy
  %XUWIND upx
  %YUWIND upy

 Using the SET command to define a window is not recommended. When the
 CLEAR command is entered, the window chosen with the last WINDOW
 command is set up, and the values of XLWIND, XUWIND,  YLWIND, and
 YUWIND are changed. Thus, if their values are re-defined with the SET
 command, their new values will be lost when CLEAR is entered.

TILE

 Syntax: WINDOW\TILE nx ny { nstart }
 Default: nstart = 1

 The WINDOW\TILE command divides the graphics page up into nx horizontal
 by ny vertical windows, giving the first window the number nstart, which
 must be > 0. The total number of windows just defined will be nx*ny.