# Revision history [back]

sage: find_fit?
<snip>
ALGORITHM:

Uses scipy.optimize.leastsq which in turn uses MINPACK's lmdif and
lmder algorithms.


So my best guess is that something changed with Scipy. I do find it odd that there is that much of a regression, and that the second exp is so tiny in the 6.5 version.

I tried it in Sage 5.13, and not only did I get a strange error

scipy/optimize/minpack.py:402: RuntimeWarning: Number of calls to function has reached maxfev = 1400.


but also I got another picture, this one with error 9.8. In Sage 5.2, though, the solution is the same as the one you get with Sage 6.5! That makes no sense but at any rate it seems like perhaps Scipy optimize might be a little wonky.