Mathematica/AVS modules

PURPOSE
These modules allow communication between Mathematica and AVS.
With them one can transmit geometries and fields from Mathematica
to AVS and fields from AVS to Mathematica.

REQUIREMENTS
Mathematica: V2.1 Mathematica or later.
AVS: Pre-Version 4.0 AVS will need to modify the networks.

TO BUILD
Each directory contains C files, makefiles, a file of
Mathematica code and a txt file.  There are makefiles for
different systems.   The main difference between these is
the command which is used to start a window in which to run 
the Mathematica session.   This is xterm for a SPARC and
dxterm for a DECstation.

PROBLEM
If you use Mathematica V2.1 to build the modules for 
other than the DECstation there is a name conflict for 
string_to_argv which is defined in both the MathLink
and AVS libraries.  This can be simply resolved by editing the
MathLink library with an editor such as emacs and changing the
two instances of string_to_argv with a name of the same length
such as MLring_to_argv.   The MathLink library is called libML.a
and can normally be found in /usr/lib...

TO USE
When each module is invoked a window is started running Mathematica
with the input and output of the window directed to and from the
Mathematica session main loop.  Entering Mathematica commands
into the window will result in the appropriate Mathematica
results.  The session is initialised with a package of Mathematica
commands which have started a MathLink communication channel to AVS.
Other initialisations are made to support the behaviour of the
particular module.

The module will search for the package of Mathematica code, for
example AVSGeometry.m, in the following order

in directory math from the environment variable AVS_PATH
in the environment variable AVS_MATH_PATH
in /usr/avs/math
in ~
in ~/AVS
in ~/AVS/math
in .
in ./AVS
in ./AVS/math

if it fails to find the package in any of these an error will result.
Thus the package should be installed in one of these places.

The txt file is used for the documentation.   This should be placed
in somewhere which is on AVS_HELP_PATH for example in /usr/avs/math/help
Each txt file contains a sample network to build as well as some
sample commands to enter to the Mathematica to make them operate.


TROUBLESHOOTING

If the module does not start up properly or if a Mathematica
session does not appear in a window on the screen the problem
is almost certainly that the Mathematica package has been loaded.
A message will be printed on the terminal from which avs was started.
Follow the instructions in the previous paragraph to rectify the
situation.


COPYRIGHT

You are free to copy and distribute these files. 
Feel free to modify and enhance them.

This work was done at WRI by Tom Wickham-Jones and Oleg Perelet with
help from Ham Lord and Robert Mazaika at AVS.

Comments can be sent to:
	Tom Wickham-Jones twj@wri.com
	Oleg Perelet	  perelet@wri.com