.BG
.FN X
.TL
X: Graphics Device Driver for the X Window System
.CS
X(width,height,ask,display,font,xbias,ybias)
.PP
.AG width
.AG height
real, the dimensions (in inches) of the window to be opened for S graphics.
.AG ask
logical, should device driver ask before clearing 
graphic display for a new figure?
Default TRUE.
.AG display
character, the name of the display the graphics window is to be opened on.
The default is to use the value of the DISPLAY environment item.
.AG font
character, the name of the font to be used in the graphs.
The default is 9x15.
.AG xbias
.AG ybias
Many of the X fonts place the asterisk high
in comparison with other characters.
These parameters allow the specification of biases (in pixels)
to ensure that the asterisk is exactly centered on the right
point.
For example, the correct offsets for the `helvR14' font are
xbias=1 and ybias=7.  A little experimentation
usually yields the right values.
.SH COMMENTS
The function `X' is the device driver for bitmapped displays
running under Version 11 of the X Window System.
When the driver starts users must position and size a
window for the graphics to appear in.
The default window is placed in the upper right of the display.
The graphics window can be resized in the usual X fashion.
.PP
If `ask' is TRUE,
then whenever a new plot is about to be produced the message "GO?" appears.
This allows further viewing,
before the graphics screen is erased.  When ready
to proceed, simply hit carriage return.
.PP
For graphic input, position the cursor with your pointing device push the left button.
Pressing the middle button terminates graphic input.
.PP
The X driver allows a color specification in graphical functions.
This has no effect on line drawing, but will cause areas to
be shaded (in barplots for example).
.PP
A device must be specified before any graphics functions can be used.
.KW device*
.WR