[ESS] Choosing between multiple *remote* R versions

[Lasko, Thomas A]

Hi folks,

I am trying to figure out how to set things up so I can choose between multiple versions of R running on a remote server that I access using emacs/ess/tramp. I know how to do this for different local R versions, but the same strategy hasn't worked for different remote versions. I've scoured the web, various manuals, and searched these archives all to no avail. But I have to believe there's a way to do it.

I use emacs tramp mode to edit R files on my remote CentOS machine, and to start R 2.15.0 processes on that machine with M-x R, which just works (amazingly easy). For a specific purpose, I now also have Revolution R 2.13 installed on that machine (under a symlink named Revo64), and I can run it fine from an ssh command line, or I can change the path environment variable so that the Revo R version always starts with M-x R. But I need to be able to selectively run each of these versions via tramp, and I'm having trouble figuring out how to set that up.

I know that at least for local versions, there's a variable ess-r-versions where I can list the prefix of each R version potentially found in my path, such as R-2, R64, R-devel, (and for me now, Revo), etc, and they will be available to ESS as processes that can be run under M-x R64, etc. I can get this working for local versions of R, but not for remote versions. I'm guessing that ESS does a search for the versions at startup, long before the remote connection is made, so they are not detected as possible choices.

Does anybody know how to set things up so that I can choose between multiple R versions on a remote machine when I am using emacs/ESS/tramp mode? Apologies if this is spelled out in documentation or previously answered somewhere - I did try to find it.

My setup: local ESS 12.04, Aquamacs 2.4 (GNU Emacs 23.3.50.1) OS X 10.7.4, remote CentOS 6.0

Tom