### You can run this ``from anywhere'' via
### source("ftp://stat.ethz.ch/U/maechler/R/mltloc-ex.R", echo = TRUE)
### ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

## From: Mark Lyman <mlyman@byu.edu>
## To: r-help@stat.math.ethz.ch
## Subject: [R] Bug in lmer?
## Date: Thu, 29 Sep 2005 14:44:38 -0600

## I am relatively new to R so I am not confident enough in what I am doing
## to be certain this is a bug. I am running R 2.1.1 on a Windows XP
## machine and the lme4 package version 0.98-1. The following code fits the
## model I want using the nlme package version 3.1-60.

if(FALSE)
mltloc <- read.table("~/R/MM/Pkg-ex/lme4/mltloc.tab", header=TRUE)
mltloc <- read.table("ftp://stat.ethz.ch/U/maechler/R/mltloc.tab", header=TRUE)

## not needed: mltloc$loc <- factor(mltloc$loc)
mltloc$block <- factor(mltloc$block)
mltloc$trt   <- factor(mltloc$trt)

str(mltloc)
## is completely 'balanced' :
with(mltloc, ftable(table(block, trt, loc)))

library(nlme) ; packageDescription("nlme")

Mltloc <- groupedData(adg ~ trt | loc, mltloc)
plot(Mltloc)
plot(Mltloc, outer=~trt)

m1 <- lme(adg ~ trt, random =
          pdBlocked(list(pdIdent(~1), pdIdent(~block-1), pdIdent(~trt-1))),
          data = Mltloc)
summary(m1)

## The problem is that when I try fitting the model using the lmer function
## with the following code:

library(lme4) ; packageDescription("lme4") ; packageDescription("Matrix")

m2 <- lmer(adg ~ trt + (1|loc)+ (1|block:loc)+ (1|loc:trt),mltloc)

##- I get this message from Windows and R closes.

## >> R for Windows GUI front-end has encountered a problem and needs to
## >> close.  We are sorry for the inconvenience.

##- This same code works on a Macintosh. So it doesn't seem that I have made
##- an error in my code. Also if anyone of the random effect terms is
##- removed there is no problem. Is this something that is being looked at?
##- Or I have I made a mistake somewhere?

summary(m2) # shows similar things as 'm1' above