OVERVIEW:

Xplot is intended for viewing 2D graphics in an X window, and
is part of the GNU 2D graphics package.

The input is accepted in the plot(5) format used by "graph" and
"axis", which interpret 2-column data files as 2D curves, and
by "dra", which is an interactive 2D plotting program. There is also
a set of C-callable routines (see plot(3)) that will bring up
a window and allow simple graphics to be drawn in real time.
See the man file for details of changes from earlier versions
of the plot format accepted.

DEFINES:

The WideLabel #define is useful with most versions of "graph". It
changes the current point to account for the size of a label.

The KeepScale #define means that a circle really is a circle
on the screen. If this is not defined, the ratio of the x to the
y coordinate ranges in the space() command is used, so that the
space requested occupies the full window area available.

The Resize_Yes #define means that input data will be buffered to allow
for correct resizing of the window. Resizing is certainly nice,
but if you've sent xplot 60 Meg of plot data, you probably don't
want it storing all that junk (I'm serious, I have sent such large files).
Every erase() command causes the data storage to be flushed, however,
so plotting many files one after the other on the same  window (possible
with the -n option, or through calling xplot from within a program) does
not cause problems.

See xplot.man for details on how the options work.

HISTORY:

Xplot (version 1) was created as a result of the frustration of one of
the authors (Arthur Smith) with the only other X-windows "plot" possibility,
the Tek window that comes with each xterm. Version 2 fixed some bugs but
otherwise had no enhancements. This version was then taken by the gnuplot
people and modified to be used as their X-window plotting surface. It
was also donated to the FSF and modified by Rich Murphey to be a little
more portable, and to take some of the GNU plot extensions (this is where
the ChangeLog begins).

The original xplot couldn't do much more than a Tektronix screen, but
with the GNU plot extensions, line colors and fonts (and filling) are
now changeable from within the plot file.  Xplot is now able to accept
input from several files on the command line, producing a new plot window
for each.

Xplot originally used Athena widgets, but (1) They changed with R4,
(2) They are not available on various machines that do use X (IBM
workstations, Silicon Graphics machines), and (3) they made the
executable about 5 times larger than it needed to be. Thus, xplot
now uses only Xlib calls, and has been compiled (using the simple
Makefile, though you can use the IMakefile if you really want) and
tested on the following:

	Sun 3/50 running SunOS 3.5 and X11R4
	NeXTstation running 2.1 and X-mouse (a port of R4)
	Sun Sparc 1 and 2 running SunOS 4.1.1, both with R4 and R5
		-also partially tested under OpenWindows 2
		(it seems to crash the OpenWindows server when asked
		 to plot too many files at once. Don't know why.)
	Silicon Graphics IRIX Sys V Release 3.3.2 and R3 libraries etc.
	IBM RS 6000 running AIX 3.1.5, with vendor libraries, etc.

If you have something different running X and you got xplot to
compile and run with no problems, or if you had to make some changes, please
send e-mail to:

	asmith@icose.msd.anl.gov

FUTURE:

The C-callable libraries and a named-pipe form for xplot should be
available with the next release of GNU Graphics.
