Install Scipy through pip install in mac os x

When canopy visual environment has been installed, you might find your can't install Scipy to /usr/local/lib/python2.7/ anymore, or you might encounter pip "DistributionNotFound" Error. The solution is to reinstall python like this, using the soft way. Then pip install scipy.

Python package "intonation" needs Scipy.

Plot histogram of a recording object might cause float error in mac os backend.  Try to use:

import matplotlib
matplotlib.use("Qt4Agg")

before import anything from pylab.