[R] Coefficients and standard errors in lme

[Andrew Robinson]

Sebastian,

you might take a look at the function "estimable" in the package gregmisc.  
We've had a lot of luck with that.

Andrew

On Tuesday 23 March 2004 09:36, Sebastian Luque wrote:
> Hello,
>
> I have been searching for ways to obtain these for combinations of fixed
> factors and levels other than the 'baseline' group (contrasts coded all
> 0's) from a mixed-effects model in lme. I've modelled the continuous
> variable y as a function of a continuous covariate x, and fixed factors
> A, B, and C. The fixed factors have two levels each and I'd like to know
> whether the relationship between y and x varies between levels of the
> factors, and whether there are any interactions between these factors.
> I've therefore setup the model as this:
>
> lme.fit <- lme(y ~ x*A*B*C, data=df, random=~x | subjectID)
>
> The contrasts are default ("contr.treatment" and "contr.poly"). As
> usual, the summary provides the coefficients for the 'baseline' group.
> The rest of coefficients correspond to *differences* and their standard
> error with respect to this group. One can calculate the coefficients for
> any combination of factor levels by adding the appropriate coefficients
> in the results. However, I don't understand how to obtain the standard
> errors for these from the summary report. Can someone please let me know
> how to obtain these?
>
> Cheers,
> Sebastian
>
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