[r] How do I change the default library path for R packages

Facing the very same problem (avoiding the default path in a network) I came up to this solution with the hints given in other answers.

The solution is editing the Rprofile file to overwrite the variable R_LIBS_USER which by default points to the home directory.

Here the steps:

1. Create the target destination folder for the libraries, e.g., ~\target.
2. Find the Rprofile file. In my case it was at C:\Program Files\R\R-3.3.3\library\base\R\Rprofile.
3. Edit the file and change the definition the variable R_LIBS_USER. In my case, I replaced the this line file.path(Sys.getenv("R_USER"), "R", with file.path("~\target", "R",.

The documentation that support this solution is here

Original file with:

 if(!nzchar(Sys.getenv("R_LIBS_USER")))
     Sys.setenv(R_LIBS_USER=
                file.path(Sys.getenv("R_USER"), "R",
                          "win-library",
                          paste(R.version$major,
                                sub("\\..*$", "", R.version$minor),
                                sep=".")
                          )) 

Modified file:

if(!nzchar(Sys.getenv("R_LIBS_USER")))
     Sys.setenv(R_LIBS_USER=
                file.path("~\target", "R",
                          "win-library",
                          paste(R.version$major,
                                sub("\\..*$", "", R.version$minor),
                                sep=".")
                          ))