This depends on what else is going on. My guess is that you are running
the Aqua GUI, and it is servicing the GUI which is taking the time, not R
itself.
On all of Linux, Solaris and Windows (RGui or Rterm) Sys.sleep() does use
very close to zero resources at the beginning of a session, but things may
be different if e.g. tcltk widgets are in use.
On Fri, 29 Jul 2005, Don MacQueen wrote:
> I done something very similar -- have R watch a file, and whenever
> new data is added to the file, read the new data from the file. In my
> case, new data was arriving once per minute, so I needed to have R
> wait about a minute before looking for new data.
>
> On my unix-based system, I found that if I usd
I don't think your system IS `unix-based' (Unix is a trademark, and MacOS
X is based on a rather different kernel). It is quite possible that it is
behaving differently from the POSIX description of Unix system calls on
which R is based for Unix-alikes.
> Sys.sleep( N )
> then cpu usage immediately went up drastically. If the the system is
> otherwise fairly idle, cpu usage goes up to nearly 100%. A cpu
> monitor shows that R is using the cpu cycles.
>
> If I use instead
> system('sleep N')
> cpu usage does not go up.
Does that freeze the GUI? It certainly freezes tcltk widgets on Unix.
> (where N is the number of seconds to sleep)
>
>> version
> _
> platform powerpc-apple-darwin7.9.0
> arch powerpc
> os darwin7.9.0
> system powerpc, darwin7.9.0
> status
> major 2
> minor 1.1
> year 2005
> month 06
> day 20
> language R
>
>
> At 12:13 PM -0700 7/29/05, Tae-Hoon Chung wrote:
>> Hi, All;
>>
>> I have a question. In R, what is the best way to make R idle for a while and
>> try something again later? For example, suppose there is an R job which
>> accesses a file that may be shared with other active jobs. So when the file
>> is being accessed by other job, your job will not be able to access the file
>> and your job will crash because of that. To avoid this, you want your job to
>> try to access the file repeatedly with some time interval, say every 10
>> seconds or something like that. Which is the best way to do this in R?
--
Brian D. Ripley, [EMAIL PROTECTED]
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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