[R] Syntax in lmer...

[Anne Kempel]

Sorry for bothering you - but I have a little problem. I`m completely 
new in R and trying to use lmer. That works, but I m not sure if my code 
is right, so I would just like to get an opinion from the experts.

I have a Growthrate of plants (RGR
Fixed Factors: Fertilizer, Status (alien or native plants) and their 
interaction
Random Factors: Age is a covariable; than I have plantfamily and Species 
nested within Family.
Now I want also to test for the interaction of Fertilizer with 
plantfamily and species. Did I do this the right way, and is the 0+ 
necessary?

model<-lmer(RGR~Fertilizer+Status+Fertilizer:Status+(1|Age)+(1|Family/Species)+(0+Fertilizer|Family/Species),data=rgr)

I`m thankful for any comments!
anne



-- 
Anne Kempel
Institute of Plant Sciences
University of Bern
Altenbergrain 21
CH-3103 Bern
kempel at ips.unibe.ch