This is XGraph, an X11 plotting programme. Originally by David Harrison, further
development by R.J.V. Bertin (RJVB) into a data exploration/processing tool.
Currently known to work on Mac OS X 10.6, Linux and Cygwin - which probably means
it'll run on anything "*n*xy" with an X11 server.

Here's what my resumé says about XGraph:
After acquiring data, one typically wants to visualise/explore, often process and usually
analyse them. In the early nineties, during my PhD work, I found a Unix/X11 application
that allowed to do this to a rather basic extent, and that came with its own GUI toolkit.
Over the years, I expanded this tool according to my needs, rather than starting from
scratch or resort to using (expensive) commercial solutions. Today it is a tool that
allows the rapid import and visualisation of large bodies of data and to explore them
interactively and programatically, using multiple windows if necessary. It allows to
generate figures (plots) that can be exported for printing, PDF conversion or editing in
applications like Adobe Illustrator. Data can be cross-associated or tagged with meta-data
and there is an API to write import plugins for novel file formats. It has its own
embedded language (complete with "JIT" byte compiler) that evolved from one of my
Patchworks modules and that can be extended via plugins. It can also interface to Python
via a plugin, adding support for embedded execution of Python code and extending the
internal functions to Python. Data processing, filtering and generation are possible at
several levels (offline or at various phases of the rendering chain) using the own
embedded language or Python. The integration with Python also gives access to a vast
quantity of extensions for scientific and statistic applications, for instance for data
import/export (Matlab's .mat files) or for interfacing with the statistics and signal
processing environment R (www.r-project.org). This is the tool that I used to process and
analyse the data (including the neurophysiological data) from my studies on simulator
sickness, but also to generate trajectories for driving simulator studies. XGraph still
works under Unix/X11 but nowadays that includes Mac OS X, Linux and Cygwin on MS Windows.


Please, have a look at the other README files, especially README.INSTALL that contains
detailed (I hope) instructions on building and installing. Sorry for the old-fashioned
manual way in which this must be done, but I myself prefer to work that way :)
Alternatively, if you have Linux running on (probably) at least a Pentium class processor,
try the xgraph binary that *may* be provided together with the source distribution.

This distribution changes often, whenever I find a bug, or need some new functionality.
The only trustworthy indication of the version, revision etc. is the date of the distribution
archive itself, and of the files contained within.

I attach a lot of importance to backward compatibility, so something that once worked should
continue to work. If not, drop me a note!

Above, before and during it all, have fun using it. It has been and still is my programme
of choice for anything from quickly looking at data to complicated processing. I am not trained
as a professional programmer (just a nearly full-time one :)), nor a computer scientist. The
original programme had many "hackery-kludgy" solutions for seemingly trivial problems like
determining the correct printing width of a string. I am improving on many of these, but in
many cases with a good solution of a similar nature (to stick with the example, those widths
are now determined by invoking gs [ghostscript] with the string in question... Yes, I know,
I could do these things with the T1lib, but see the TODOHIST file for some thoughts on that).

This programme is freeware. You may use it for your own use, (re)distribute it, etc, as
long as you keep the original copyright notice (from David Harrison) intact, as well
as my own.

If you find bugs, implement improvements or additional features (have a look at TODOHIST),
PLEASE let me know about them!

(C) R.J.V. Bertin, 1990, 2001, 2012, 2013 (this README)