[R] lme library

[Ben Bolker]

 <roberta_varriale <at> ds.unifi.it> writes:

> I’m able to estimate a null model.
> For example, using SAS data, I can estimate the model:
> lme(y ~ 1, data = Mississippi, random = ~ 1|influent, method="ML")
> 
> As suggested in the literature I want to “test” the significance of the
> second level variance. So, I would like also to estimate a linear model
> without random effects. Is it possible with your library?
> In the description of the function lme I found that the random part is
> optional, but I don't know how to remove it.


  In general, linear models without random effects are fit with
lm() , which is part of base R.  If you need other fancy things
(heteroscedasticity, spatial autocorrelation etc.) you can use
gls in the nlme package.

  Ben Bolker