To install:

1. If not alread installed, download and install the following packages:

	a. The numpy python library - provides fast floating-point array 
		operations in python. Versions earlier than 1.6 may not work.
		(http://numpy.scipy.org/)

	b. The Cython python package - provides a variant of python that 
		compiles into C code that can itself be compiled and is faster (but
        less flexible) than ordinary python. Versions earlier than 0.17
		may not work. 
		(http://www.cython.org/)

	c. The matplotlib package for 2-d plotting. This is optional
		unless you want to make pictures of the vegas grid
		(see the documentation on How vegas Works).

	c. The gvar module which handles Gaussian random variables. This is not 
	    strictly required but greatly improves postprocessing of vegas results,
	    especially when integrating array-valued integrands. gvar is can be
	    installed as part of the lsqfit distribution (pip install lsqfit) or
	    it can be installed by itself (pip install gvar).
		(http://https://github.com/gplepage/lsqfit.git or use pip)

	The first three of these libraries are usually included in 3rd-party
	distributions of python. 

	The vegas code works for Python 2.7 and 3.3. It has not been tested
	for earlier versions.

2. Use 'make install'. This will build the vegas packages, and 
	then copy it into a standard directory in the user's space that
	Python knows about. A list of the installed files is stored in file
	files-vegas.python (in case, for example, you want to uninstall them).
	
	N.B. Rather than using make and the makefile, one can instead use 
	standard distutils commands: eg, 'python setup.py install --user'
	
	N.B. If you have previously installed older versions of vegas,
	consider removing the earlier modules to make sure that the new ones are 
	used by Python. This will not be a problem if the new modules overwrite
	the older ones, but could cause trouble if the new modules are written 
	to a different place. Find out where the older modules are stored by
	using 'pydoc vegas' before installing the new software
	(pydoc lists the location of the module under "FILE").
	
	N.B. To install vegas for an alternative version of python, say python3 
	for example, use 'make PYTHON=python3 install'. Python's standard 
	directories are structured in such a way that it is necessary to do 
	a separate installation for each python version that will be used for 
	vegas.
		
3. (Optional) Run 'make tests' to test your installation of vegas. 
	The tests have been successful if the output ends with "OK". 
	Some tests involve random numbers and so may occasionally --- less than 
	1 in 100 runs --- fail due to rare multi-sigma fluctuations; rerun the 
	tests if they do fail. Contact g.p.lepage@cornell.edu if there are 
	persistent, frequent failures.
	
	N.B. The tests can also be run directly using Python's unittest module:
	"python -m unittest discover".

4. (Optional) Change to subdirectory examples/ and look at some of the 
 	sample .py files given there that use vegas. Run them one by one --- 
	"python simple.py" etc --- or all at once using "make run".
	
5. (Optional) Use 'make clean' to erase work files/directories.


To uninstall:

1. 'make uninstall' (probably) uninstalls most of what was installed. It 
	relies upon files with names like "files-vegas.python" that were 
	created during installation.


Problems:

	Contact Peter Lepage: g.p.lepage@cornell.edu


# Created by G. Peter Lepage (Cornell University) in 12/2013.
# Copyright (c) 2013-14 G. Peter Lepage. 
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# any later version (see <http://www.gnu.org/licenses/>).
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.


