Dear R members,

I tried to fit an lme model and to use the glht function of multcomp.  
However, the glht function gives me some errors when using  
weights=varPower().
The glht error makes sense as glht needs factor levels and the model  
works fine without weights=. Does anyone know a solution so I do not  
have to change the lme model?

Thanks
Sibylle

--> works fine
ME$Diversity=factor(ME$Diversity)
H08_lme<-lme(log(Height2005_mean)~Diversity, data=ME, random=~1|Plot/ 
SubPlot, na.action=na.omit, subset=ME$Species=="Pse_men", method="ML")
summary(H08_lme)
anova(H08_lme)
g_H08_lme<-glht(H08_lme, linfct=mcp(Diversity="Tukey"))
print(summary(g_H08_lme))

--> using lme with weights I changed the order of factor() and  
introduced as.factor in the model

H08_lme<-lme(log(Height2008_mean)~as.factor(Diversity), data=ME,  
random=~1|Plot/SubPlot, weights=varPower(form=~Diversity),  
na.action=na.omit, subset=ME$Species=="Ace_pse", method="ML")
summary(H08_lme)
anova(H08_lme)
ME$Diversity=factor(ME$Diversity)
g_H08_lme<-glht(H08_lme, linfct=mcp(Diversity="Tukey"))

Error in mcp2matrix(model, linfct = linfct) :
   Variable(s) ‘Diversity’ have been specified in ‘linfct’ but cannot  
be found in ‘model’! 
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