[R-SIG-Mac] R Versioning and Packages

[Duncan Murdoch]

On 17/04/2015 5:54 AM, Roy Mendelssohn - NOAA Federal wrote:
> Hi All:
>
> Since R 3.2 has been released and the Mac version should be available shortly, I always forget how the R versioning system and updates relate to installed packages. Some updates work with what you have installed, some do not.  I know if the update was to R version 4.x I would likely have to re-install packages.  Will this require reinstallation, and in general at what level of update is this the case.

In version x.y.z, you probably won't need to update if only z changes, 
but you will if x or y changes, so you should update in this case.

An easy way to do this is to copy all the packages to the new 
installation, then run

update.packages(checkBuilt = TRUE)

This will reinstall any packages that were built under an earlier 
version of R. (I believe it ignores z in this choice.) The only 
disadvantage to doing this is that you will go to the latest version of 
all packages, and you might have been postponing that due to 
incompatible changes.

Duncan Murdoch