Linux or OS X on Macbook Pro Retina?
Where does a Maccer get the 'brew' command from? Reading these docs: http://mxcl.github.io/homebrew/ seems to imply you first need Ruby. Is that installed on every Mac?
Yes, you just run: ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go)" all macs have ruby on them already.
does that brew command require an rgdal 'formula' somewhere? I cant find one here: https://github.com/mxcl/homebrew/blob/master/Library/Formula
You want rgdal from brew, and then rgdal from CRAN.
or is it a case of installing R from homebrew and then 'gdal' for the
libraries and then the rgdal package via install.packages from source?
1. install Ruby
2. install homebrew
3. start a Terminal
3.1 brew install r
3.2 brew install gdal
4. run R
4.1 install.packages("rgdal",type="source")
Yes, except I usually just install the binary R distro from CRAN (and 3 needs to come before 1). Hadley -- Chief Scientist, RStudio http://had.co.nz/