[R-SIG-Mac] How to start two different versions of R on a Mac (in emacs)?

[Hofert Jan Marius]

Dear expeRts,

I recently switched to emacs (aquamacs) and I am amazed by its capabilities. I used to use RSwitch to switch between R-2.13 and R-2.14. Since I am now able to start R in different frames of emacs, I was wondering if I can simply start R-2.13 in one frame and R-2.14 in another frame. 

On experimenting, the first thing I realized was that in a terminal, I only have "R", "R32" and "R64" available; so no "R-2.13.32bit", "R-2.14.32bit", "R-2.13.64bit", "R-2.14.64bit" [or similar]. If I start "R", it starts the version that RSwitch has selected. But that means I can't start different R versions at the same time... However, I know that it works on Linux, so is there a Mac solution, too? It would be nice if one is not required to use RSwitch but can simply choose in emacs which R version should be started. 

The first step seems to be to locate the different installed R versions, which should probably be in /Library/Frameworks/R.framework/Versions/2.13/Resources and /Library/Frameworks/R.framework/Versions/2.14/Resources. But if RSwitch points to R-2.14 and I start the R version in the former directory (so R-2.13), it starts R-2.14 anyway... 

Cheers,

Marius