bug?

Antonio.Gasparrini at lshtm.ac.uk wrote:

Dear all,

I found a problem with 'lme4'. Basically, once you load the package 'aod' (Analysis of Overdispersed Data), the functions 'lmer' and 'glmer' don't work anymore:

library(lme4)
(fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy))
(gm1 <- glmer(cbind(incidence, size - incidence) ~ period + (1 | herd),
              family = binomial, data = cbpp))
install.packages("aod")
library(aod)
(fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy))
(gm1 <- glmer(cbind(incidence, size - incidence) ~ period + (1 | herd),
              family = binomial, data = cbpp))

Taking into account that this package is used to perform similar analyses, this could be a problem.

All the best

 It looks like you already posted this to r-help and got some answers
(i.e., this is a problem with aod changing the S4 method for "AIC").

 For convenience, I sometimes use functions like this

load_lme4 <- function() {
 try(detach("package:nlme"),silent=TRUE)
 library(lme4)
}

load_nlme <- function() {
 try(detach("package:lme4"),silent=TRUE)
 library(nlme)
}

 to switch back and forth between lme4 and nlme (which also
don't play all that nicely with each other) -- you could do
the same sort of thing if you are going to use lme4 and aod
in the same R session.

 Ben Bolker