This brings me to another suggestion for future releases:
The present combination of ATK, Python and Matplotlib is really a nice thing.
However, it may be a good idea to keep up with the Matplolib versions from time to time.
I post this here, because
import pylab
pylab.semilogy([1,2,3])
pylab.show()
throws an error. This is a known and meanwhile fixed bug in Matplotlib.