[R] Fitting exponential curve to data points

Dieter Menne dieter.menne at menne-biomed.de
Tue Jul 24 17:59:29 CEST 2007

Andrew Clegg <andrew.clegg <at> gmail.com> writes:

> ... If I want to demonstrate that a non-linear curve fits
> better than an exponential, what's the best measure for that? Given
> that neither of nls() or optim() provide R-squared. 

To supplement Karl's comment, try Douglas Bates' (author of nls) comments on the


Short summary:
    * ... "the lack of automatic ANOVA, R^2 and adj. R^2 from nls is a feature,
not a bug :-)"
    * My best advice regarding R^2 statistics with nonlinear models is, as Nancy
Reagan suggested, "Just say no."


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