		Python connection to ds9 via XPA

The XPA messaging system (http://hea-www.harvard.edu/saord/xpa) provides 
seamless communication between many kinds of Unix programs, including Tcl/Tk
programs such as ds9. The pyds9 module uses a Python interface to XPA to 
communicate with ds9. It supports communication with all of ds9's XPA access
points. See http://hea-www.harvard.edu/saord/ds9/ref/xpa.html for more info.

To install:

	# unpack the source tar file and change to the source pyds9 directory
	> gunzip -c pyds9-1.4.tar.gz | tar xf -
	> cd pyds9-1.4

	# install in default system directory
	> python setup.py install

or
	# install in specified directory
	> python setup.py install --prefix=<install-dir>
	> setenv PYTHONPATH <install-dir>lib/python2.x/site-packages 

To run:

	# start up python
	> python
        ... (startup messages) ...
	>>> from ds9 import *
	>>> print ds9_targets()
	>>> d = ds9()

etc.

The setup.py install will build and install both the XPA shared library and 
the xpans name server. By default, the code generated for the shared object
will match the address size of the host machine, i.e. 32-bit or 64-bit
as the case may be. But on 64-bit Intel machines, the XPA build also will check
whether python itself is 64-bit. If not, will add the "-m32" switch to the
compile options to build a 32-bit shared object. This check can be overridden
by defining the CFLAGS environment variable (which can be anything sensible,
including an empty string).

For Linux, the X Window System libraries and header files must be available.
On some versions of Linux (e.g., debian), the development libraries must be
installed explicitly. If you have problems, please let us know.

Contact saord@cfa.harvard.edu for help.

Eric Mandel
