[R] Crossed random effects in lme

[Douglas Bates]

Søren Højsgaard <sorenh at agrsci.dk> writes:

> Dear all,
> In the SASmixed package there is an example of an analysis of a split-plot experiment. The model is
> 
>   fm1Semi <- lme( resistance ~ ET * position, data = Semiconductor, random = ~ 1 | Grp)
> 
> where Grp in the Semiconductor dataset is defined as ET*Wafer. Is it possible to specify the grouping directly some way, e.g. like 
> 
>   fm1Semi <- lme( resistance ~ ET * position, data = Semiconductor, random = ~ 1 | ET*Wafer)

Actually that does work with lme from the as-yet-unreleased version
0.6-1 of the lme4 package.  See the slides from my presentation at
useR!2004
 http://www.ci.tuwien.ac.at/Conferences/useR-2004/Keynotes/Bates.pdf

I'm back at my home now and will endeavor to get lme4_0.6-1 released
as soon as possible.

-- 
Douglas Bates                            bates at stat.wisc.edu
Statistics Department                    608/262-2598
University of Wisconsin - Madison        http://www.stat.wisc.edu/~bates/