[R] R doesn't recognize R_HOME value
Prof Brian Ripley
ripley at stats.ox.ac.uk
Wed Jul 25 07:58:15 CEST 2012
On 24/07/2012 21:57, Kirk Fleming wrote:
> Windows 7 is where I'm seeing the problem.
> The root problem: while I have R_HOME legitimately specified within Windows
> 7, and issuing 'set R_HOME' from the command line returns exactly the path
> I've specified, doing a Sys.getenv('R_HOME') from R returns a completely
> different path.
> I ask, "What would cause a Sys.getenv() call to return a different value
> than the OS does?"
A different process and hence a different environment ... this is why
they are called 'environment variables' and are specific to a process.
'The command line' is actually a shell process, not the OS itself.
Setting environment variables in a shell affects only that shell and
those which inherit from it.
See ?R_HOME in R, which tells you that is the R process 'is normally set
on startup'. 'Normally' because there are many ways to start R
(embedded, for example: see 'Writing R Extensions'), and you have not
actually told us how you started R. But Rgui.exe and Rterm.exe do
always set R_HOME.
Brian D. Ripley, ripley at stats.ox.ac.uk
Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/
University of Oxford, Tel: +44 1865 272861 (self)
1 South Parks Road, +44 1865 272866 (PA)
Oxford OX1 3TG, UK Fax: +44 1865 272595
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