Updates for the diffusion tensor optimization sample script.
The problem was identified (for sample script "dasha.py")
by Shantanu Bhattacharyya <shantanu01 att cmu dott edu> in the post at
https://mail.gna.org/public/relax-users/2011-05/msg00018.html (Message-id:
<7a068ac7a9e90b8e8d374b334a20d4be.squirrel@...>).
