python - core dumped


I try to do something with py-scipy but I have a problem with Segmentation fault (core dumped).
I did try one "example" file but it is the same problem. It calculated but doesn't show picture:
One-dimensional Schrodinger equation - time evolution
Wavepacket energy:    0.0124932555014
Potential type:       step
Potential height V0:  0.01
Barrier thickness:    15
Segmentation fault (core dumped)

Here is the link of the example:
http://scipy-cookbook.readthedocs.i....html?highlight=quantum mechanical simulation

Any idea what is wrong on my FreeBSD 11-RELEASE (amd64) and Python27, please?