How to upgrade R on windows XP – another strategy (and the R code to do it)

Update: This post has a follow-up for how to upgrade R on windows 7 explaining how to deal with permission issues.

Background – how I heard that there is more then one way to upgrade R

If you didn’t hear it by now – R 2.11.0 is out with a bunch of new features.

After Andrew Gelman recently lamented the lack of an easy upgrade process for R, a Stackoverflow thread (by JD Long) invited R users to share their strategies for easily upgrading R.

Upgrading strategy – moving to a global R library

In that thread, Dirk Eddelbuettel suggested another idea for upgrading R. His idea is of using a folder for R’s packages which is outside the standard directory tree of the installation (a different strategy then the one offered on the R FAQ).

The idea of this upgrading strategy is to save us steps in upgrading. So when you wish to upgrade R, instead of doing the following three steps:

  • download new R and install
  • copy the “library” content from the old R to the new R
  • upgrade all of the packages (in the library folder) to the new version of R.

You could instead just have steps 1 and 3, and skip step 2 (thus, saving us time…).

For example, under windows XP, you might have R installed on:
C:Program FilesRR-2.11.0
But (in this alternative model for upgrading) you will have your packages library on a “global library folder” (global in the sense of independent of a specific R version):
C:Program FilesRlibrary

So in order to use this strategy, you will need to do the following steps (all of them are performed in an R code provided later in the post)-

  1. In the OLD R installation (in the first time you move to the new system of managing the upgrade):
    1. Create a new global library folder (if it doesn’t exist)
    2. Copy to the new “global library folder” all of your packages from the old R installation
    3. After you move to this system – the steps 1 and 2 would not need to be repeated. (hence the advantage)
  2. In the NEW R installation:
    1. Create a new global library folder (if it doesn’t exist – in case this is your first R installation)
    2. Premenantly point to the Global library folder whenever R starts
    3. (Optional) Delete from the “Global library folder” all the packages that already exist in the local library folder of the new R install (no need to have doubles)
    4. Update all packages. (notice that you picked a mirror where the packages are up-to-date, you sometimes need to choose another mirror)

Thanks to help from Dirk, David Winsemius and Uwe Ligges, I was able to write the following R code to perform all the tasks I described :-)

So first you will need to run the following code:
Continue reading How to upgrade R on windows XP – another strategy (and the R code to do it)