[R] Nonlinear weighted least squares estimation

[Robert Brown FM CEFAS]

Hi there,

I'm trying to fit a growth curve to some data and need to use a weighted least squares estimator to account for heteroscedasticity in the data.  A weights argument is available in nls that would appear to be appropriate for this purpose, but it is listed as 'not yet implemented'. Is there another package which could implement this procedure?

Regards,

Robert Brown