Dear R project,
I am a doctoral student in Zhejiang university in China, I am using lme function in nlme package and learning the function by Package 'nlme' document. I am writing this email for some help to build a lme model.
My goal was to include two non-nested random effects in the lme model. the document described how to write the random effects while I found it difficult for me to understand. My problem are as below:
In these model, site and year were considered as non nested effects. I want to set the structure in lme model the same as lmer model(the 1st model below), and I used the structure "random=list(site=~1,year=~1)"(the 2nd model below) . According to the result, the lme model was obviously wrong, for the R2 and AIC were different from that of lmer model. I want to know to get the same result as lmer model, how should I set the random argument?
Below is the model and results in R,
################################################################1. lmer function
lmer<-lmer(data, y~x1+x2+x3+(1|site)+(1|year))
r2(lmer)##58.8%?29.7%
r.squaredGLMM(lmer)##58.8%; 29.72%;AIC=462.4
###################################################################2. lme1
lme1<-lme(data, y~x1+x2+x3,random = list(site=~1,year=~1))
r2(lme1)## NA(can't get the result)
r.squaredGLMM(lme1)##92.4%; 30.89%;AIC=533
I will be appreciated for your help.
Yours sincerely,
Juan Liu
Juan Liu
PhD candidate
College of Life Sciences, Zhejiang University
866 Yuhangtang Road, Hangzhou
Zhejiang 310058, P.R.China
21707095 at zju.edu.cn? liujuan_1994 at outlook.com