[Rd] RE: [R] ^ operation much slower in R 1.7.1 than in R 1.7 .0 ???

[Prof Brian Ripley]

So that pretty conclusively nails this as a compiler/runtime difference.
Which versions of the compiler and mingw-runtime did you use?

We'll need to wait until Duncan M returns to find out what he used.

On Tue, 5 Aug 2003, Marsland, John wrote:

> I have both the CRAN binary and my own compiled version of R v1.7.1 on the
> same machine (Dell Pentium III 800 MHz running NT 4)
> 
> Using the example provided earlier:
> 
> > phi <- 1.6180339887498949
> > a <- floor(runif(750000)*1000)
> > system.time(b <- (phi^a - (-phi)^(-a))/sqrt(5))[3]
> 
> I get 10.99 secs on the CRAN binary and 2.09 secs on my own compiled
> version.
> 
> I hope this helps someone ... 
> 
> Regards,
> 
> John Marsland
> 
> > -----Original Message-----
> > From: Prof Brian D Ripley [mailto:ripley at stats.ox.ac.uk]
> > Sent: 05 August 2003 09:03
> > To: Philippe Grosjean
> > Cc: r-devel at stat.math.ethz.ch
> > Subject: [Rd] RE: [R] ^ operation much slower in R 1.7.1 than 
> > in R 1.7.0
> > ???
> > 
> > 
> > On Tue, 5 Aug 2003, Philippe Grosjean wrote:
> > 
> > > I propose to move this thread to R-devel...
> > >
> > > Prof. Brian Ripley wrote:
> > > >And are you able to give an explanation?  For example, did 
> > you compile
> > > >each under the same compiler system?
> > >
> > > I just noticed that behaviour yesterday, and had not much 
> > time yet to
> > > investigate it. I compiled 1.7.0 myself (but compared with 
> > the binary
> > > provided on CRAN; no changes). I used the 1.7.1 binary 
> > provided on CRAN. I
> > > know these binaries are not supported, so we (Windows 
> > users) will have to
> > > look at that by ourselve. Indeed yes, I'll first compile 
> > 1.7.1 with the same
> > > compiler I used for 1.7.0.
> > >
> > > >I doubt if this is worth R-core's time to pursue, so over 
> > to interested
> > > >users to find an explanation and fix.
> > >
> > > OK. But I was wondering if people at R-core team, 
> > especially those who
> > > worked on Windows specific aspects, would have in mind some 
> > changes they did
> > > between 1.7.0 and 1.7.1 than can cause this. Since these 
> > changes are mainly
> > > corrections of bugs, the list is hopefully not so long... 
> > and it could help
> > > a lot to have these hints. Thanks very much.
> > 
> > No idea from me, and the effect is not seen on other platforms.
> > 
> > -- 
> > 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
> > 
> > ______________________________________________
> > R-devel at stat.math.ethz.ch mailing list
> > https://www.stat.math.ethz.ch/mailman/listinfo/r-devel
> > 
> 
> 
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-- 
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