[R] weights in nls

[Douglas Bates]

ben at zoo.ufl.edu writes:

>   Does the nls package actually allow for weighted nonlinear regression?
> (i.e., I have data with individual variances associated, I'd like to use
> 1/var to weight the points.)  The "nls" function does have a weights
> argument, but it doesn't seem to do anything as far as I can tell ...

Hmm.  You're right.  The weights argument is supposed to do something
but it does not appear to be functional.  I'll look at it.

In the meantime, you can use the approach that John Chambers and I
describe in chapter 10 of "Statistical Models in S" (a.k.a. the white
book) and write the model as a one sided formula giving the weighted
residual.
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