Dear all,

lmer: is it possible to
1) first fit an lmer with usual syntax,
2) then  change the Zt matrix by
   hand and fit this changed model?

Especially; I want to fit e model
 y_gi= mu + e_g +  e_gi  for g=1,2
and for g=3 leave out the e_3:
 y_3i= mu       +  e_gi


#As an example:
# creating a simple data set with  three id's on
# which 2 repated measures are taken
id<-1:3
rep<-1:2
dat<-expand.grid(rep=rep,id=id)
e<-rnorm(id,sd=20)
names(e)<-as.character(id)
e.id<-e[as.character(dat$id)]
dat$y<-e.id+ rnorm(nrow(dat))
 #fit the model with all three e_g:
mod<-lmer(y~1 + (1|id),doFit=T,data=dat)
#
#I would like to fit a model where
# mod@Zt[3,]<-0<mailto:mod@Zt[3,]<-0>


Kind regards,

Ulrich Halekoh
University of Aarhus, Department of Genetics and Bioinformatics
ulrich.halekoh@agrsci.dk<mailto:ulrich.halekoh@agrsci.dk>



	[[alternative HTML version deleted]]


