sage: load('animate_decay.py')
sage: plt.savefig('foo.png')
The file, foo.png, contained an empty Cartesian plane. I also typed in the code verbatim into the Sage interpreter and had the same results. I am running Sage Version 5.5, Release Date: 2012-12-22 on Ubuntu 12.04.1 LTS. Any suggestions would be greatly appreciated!