[R] bug in lme4?

[Peter Dalgaard]

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
>  
> Antonio Gasparrini
> Public and Environmental Health Research Unit (PEHRU)
> London School of Hygiene & Tropical Medicine
> Keppel Street, London WC1E 7HT, UK
> Office: 0044 (0)20 79272406 - Mobile: 0044 (0)79 64925523
> http://www.lshtm.ac.uk/people/gasparrini.antonio ( http://www.lshtm.ac.uk/pehru/ )
>   
>
> ------------------------------------------------------------------------
>
> Subject:
> bug?
> From:
> <Antonio.Gasparrini at lshtm.ac.uk>
> Date:
> Wed, 20 Aug 2008 02:49:10 +0100
> To:
> <r-sig-mixed-models at r-project.org>
>
> To:
> <r-sig-mixed-models at r-project.org>
>
>
> 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.
>   
In which sense is this a bug in lme4?? I'd say that aod has the problem. 
You can't write an R package so that it is guaranteed not be clobbered 
by something loaded subsequently.

-- 
   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
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