[R-sig-ME] a problem with lme4_0.999375-0?

vito muggeo vmuggeo at dssm.unipa.it
Thu Jan 17 12:39:35 CET 2008

Dear all,

I'm running data from "Gelman&Hill Data Analysis Using regression.. 
pag259-261" (you can get data by running the code below). In particular 
I'm interested in getting variances of the predictions of the random 
intercepts. I get "right" (as compared with those from the book) results 
  using lme 0.99875-9 (downloaded from CRAN).

However using the latest lme4_0.999375-0 obtained via

install.packages("lme4", repos = "http://r-forge.r-project.org")

the variances of the predictions are wrong..(they are constant 
regardless of different cluster sizes. You can check this running the 
code below..

Many thanks,

srrs2 <- 
    header=T, sep=",")

mn <- srrs2$state=="MN"
radon <- srrs2$activity[mn]
log.radon <- log (ifelse (radon==0, .1, radon))
floor <- srrs2$floor[mn]       # 0 for basement, 1 for first floor
n <- length(radon)
y <- log.radon
x <- floor
# get county index variable
county.name <- as.vector(srrs2$county[mn])
uniq <- unique(county.name)
J <- length(uniq)
county <- rep (NA, J)
for (i in 1:J){
   county[county.name==uniq[i]] <- i

ranef(M1)[[1]][1:10,] #OK

se.ranef(M1)[[1]][1:10,] #wrong results: they are constant!!!??!!!

 > sessionInfo()
R version 2.6.1 (2007-11-26)


attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base

other attached packages:
[1] foreign_0.8-23    car_1.2-7         arm_1.1-1 
R2WinBUGS_2.1-6   coda_0.13-1       lme4_0.999375-0   Matrix_0.999375-4 
[9] MASS_7.2-38

loaded via a namespace (and not attached):
[1] grid_2.6.1

Vito M.R. Muggeo
Dip.to Sc Statist e Matem `Vianelli'
Università di Palermo
viale delle Scienze, edificio 13
90128 Palermo - ITALY
tel: 091 6626240
fax: 091 485726/485612

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