On Tue, Oct 26, 2010 at 3:28 PM, Pauli Virtanen <p...@iki.fi> wrote: > Tue, 26 Oct 2010 12:16:53 -0700, Nicolai Heitz wrote: >> I am not sure if you are the right persons to contact but if not I would >> appreciate a short notice and maybe an address where I can find help. I >> already posted this this message in an other python mailing list and >> they forwarded me to this list and told me that I might find help here. > > Some comments: > > 1) General advice: When doing numerics, it's generally a good idea to use > units natural for the problem, and not SI ones. The numbers the computer > sees should be of order 1. Not all numerical algorithms are scale > invariant.
I also think it will be difficult to get good numbers by numerical differenttiation with this scaling. > > 2) The scipy-user list might be even more appropriate: > > http://mail.scipy.org/mailman/listinfo/scipy-user > > 3) The numdifftools authors might be more knowledgeable about their > software: > > http://code.google.com/p/numdifftools/ > > If you are sure it's a bug in numdifftools, click the issues tab and > write a report. Be sure to include simple test case (like the one you > attached). Per might be reading this or scipy-user. My guess would be that it is not a bug but numerical precision problems in a difficult use case. The question is however useful, because I haven't seen much discussion yet about a robust use of numdifftools. Josef > > -- > Pauli Virtanen > > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion > _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
