[R] gnls or nlme : how to obtain confidence intervals of fitted values
montpied at nancy.inra.fr
Fri Oct 1 09:48:56 CEST 2004
I use gnls to fit non linear models of the form y = alpha * x**beta
(alpha and beta being linear functions of a 2nd regressor z i.e.
alpha=a1+a2*z and beta=b1+b2*z) with variance function
varPower(fitted(.)) which sounds correct for the data set I use.
My purpose is to use the fitted models for predictions with other sets
of regressors x, z than those used in fitting. I therefore need to
estimate y with (95%) confidence intervals.
Does any body knows how to do this with R ?
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