[R] Make installed packages available to new R version

[Mike Prager]

Roy Robertson <jroyrobertson at comcast.net> wrote:

> After installing a new version of R, how do I make the packages that I 
> have already installed and use on the old version available to the new 
> version?

Here is my solution. It has worked over many releases of R,
though it will probably require one initial re-installation of
packages.

Set environment variable R_LIBS to some permanent directory
before installing a version of R. (That is, NOT a directory
under the tree of your current R version.) When you subsequently
install packages, they will go into that location and won't need
re-installation with each new version of R. 

It's still necessary to run update.packages() periodically --
such as after installing a new R version -- to keep the
installed packages current.

-- 
Mike Prager, NOAA, Beaufort, NC
* Opinions expressed are personal and not represented otherwise.
* Any use of tradenames does not constitute a NOAA endorsement.