Message-ID: <Pine.LNX.4.44.0305151712340.1110-100000@gannet.stats>
Date: 2003-05-15T16:18:05Z
From: Brian Ripley
Subject: R as 64 bit application
In-Reply-To: <Pine.A41.4.44.0305150902550.23588-100000@homer36.u.washington.edu>
On Thu, 15 May 2003, Thomas Lumley wrote:
> On Thu, 15 May 2003, Paul Gilbert wrote:
>
> > In a package test I have a problem that needs over 4G of memory. This
> > requires that I use R compiled as a 64 bit application. Is there a way
> > within R to test if R has been compile as a 64 bit application? This
> > would allow me to automatically skip the test when I know it is going to
> > fail.
> >
>
> I don't think so. You could use a simple C function
>
>
> void is64bit (int *sizeptr){
> *sizeptr = sizeof sizeptr ==8;
> return;
> }
>
>
> is64bit<-function(){
> .C("is64bit",logical(1))[[1]]
> }
>
You could call object.size:
> object.size(numeric(0)) #32-bit
[1] 28
> object.size(numeric(0)) #64-bit
[1] 56
or you could look at the results of gc():
> foo <- gc()
> foo[1,4]/foo[1,3]*2^20
[1] 56.05374
and it's about 28 on a 32-bit system.
--
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