Re: [R] Way to make R idle for some time and try something again later

From: Don MacQueen <>
Date: Tue 16 Aug 2005 - 01:34:09 EST

At 6:44 AM +0100 7/30/05, Prof Brian Ripley wrote:
>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.

Actually, no, I am not using the Aqua GUI. Not even a "framework" build:

    ../source/configure --enable-R-shlib --with-blas=-framework vecLib --with-lapack --enable-R-framework=no

>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.

I've never tried it while using tcltk widgets.

(and apologies for the delay; I've been away from the office for two weeks)

>>(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
>>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,
>Professor of Applied Statistics,
>University of Oxford, Tel: +44 1865 272861 (self)
>1 South Parks Road, +44 1865 272866 (PA)
>Oxford OX1 3TG, UK Fax: +44 1865 272595

Don MacQueen
Environmental Protection Department
Lawrence Livermore National Laboratory
Livermore, CA, USA

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Received on Tue Aug 16 01:48:53 2005

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