[R-sig-ME] Update: Easiest way to install lme4 on Mac OS X

[Daniel Myall]

Hi,

I've had several off-list emails inquiring about installing lme4 on Mac 
OS X and the progress in determining the cause of the non-deterministic 
behaviour. Hence, a quick update:


Easiest way of installing lme4:

The package is available from R-forge as package checks are not run for 
Mac OS X on R-forge (hence the non-deterministic behaviour under Mac 
isn't flagged). However, I would only run lme4 under R 64 bit on Mac 
(where no issues have been observed).

Download and install gfortran from 
http://cran.r-project.org/bin/macosx/tools/ (available as a dmg which 
installs the required libraries for the builds from R-forge into 
/usr/local/)

In R run: install.packages(c("Matrix","lme4"), 
repos="http://R-Forge.R-project.org")


Summary of clues to what may be the cause of non-deterministic results 
of identical calls:

* I've only observed it with slightly-pathological cases and not with 
real experimental data (there will of course be real experimental data 
where the bug is exposed).
* Has only been observed in 32 bit R and not 64 bit R.
* Occurs with both vecLib and R BLAS on 10.5.8 but only with vecLib BLAS 
on 10.6.4.
* Occurs with all versions of lme4/Matrix in the past two years when run 
on R 2.11.1.
* lme4a has a slightly different behaviour in that, instead of only two 
potential results, every run has a different result.


When I have some more time I'll dig deeper into debugging each run to 
try to figure out exactly where the non-deterministic behaviour is 
creeping in. I want to get this resolved so that the package appears on 
CRAN again.

Cheers,
Daniel