difference?" (The fact that various people chimed in to say they could reproduce the behavior that bothered you, but didn't bother dig deeper suggests it didn't bother them that much, which further suggests that you are the person most motivated by this and thus the best candidate for investigating it further...)
-- Tony Plate
At Wednesday 05:07 PM 9/15/2004, Francisco Chamu wrote:
I am sorry to insist, but we have three other people that were able to reproduce the behavior I mentioned. I have also installed R 1.9.1 from the CRAN binaries on a different Windows machine and again I see the differents signs as mentioned before. What would be causing the difference?
-Francisco
On Tue, 14 Sep 2004 11:04:29 -0600, Tony Plate
<[EMAIL PROTECTED]> wrote:
> FWIW, I see the same behavior as Francisco on my Windows machine (also an
> installation of the windows binary without trying to install any special
> BLAS libraries):
>
> > library(MASS)
> > data(painters)
> > pca.painters <- princomp(painters[ ,1:4])
> > loadings(pca.painters)
>
> Loadings:
> Comp.1 Comp.2 Comp.3 Comp.4
> Composition 0.484 -0.376 0.784 -0.101
> Drawing 0.424 0.187 -0.280 -0.841
> Colour -0.381 -0.845 -0.211 -0.310
> Expression 0.664 -0.330 -0.513 0.432
>
> Comp.1 Comp.2 Comp.3 Comp.4
> SS loadings 1.00 1.00 1.00 1.00
> Proportion Var 0.25 0.25 0.25 0.25
> Cumulative Var 0.25 0.50 0.75 1.00
> > pca.painters <- princomp(painters[ ,1:4])
> > loadings(pca.painters)
>
> Loadings:
> Comp.1 Comp.2 Comp.3 Comp.4
> Composition -0.484 -0.376 0.784 -0.101
> Drawing -0.424 0.187 -0.280 -0.841
> Colour 0.381 -0.845 -0.211 -0.310
> Expression -0.664 -0.330 -0.513 0.432
>
> Comp.1 Comp.2 Comp.3 Comp.4
> SS loadings 1.00 1.00 1.00 1.00
> Proportion Var 0.25 0.25 0.25 0.25
> Cumulative Var 0.25 0.50 0.75 1.00
> > R.version
> _
> platform i386-pc-mingw32
> arch i386
> os mingw32
> system i386, mingw32
> status
> major 1
> minor 9.1
> year 2004
> month 06
> day 21
> language R
> >
>
> My machine is a dual-processor hp xw8000.
>
> I also get the same results with R 2.0.0 dev as in
> > R.version
> _
> platform i386-pc-mingw32
> arch i386
> os mingw32
> system i386, mingw32
> status Under development (unstable)
> major 2
> minor 0.0
> year 2004
> month 09
> day 13
> language R
> >
>
> -- Tony Plate
>
>
>
> At Tuesday 10:25 AM 9/14/2004, Prof Brian Ripley wrote:
> >On Tue, 14 Sep 2004, Francisco Chamu wrote:
> >
> > > I have run this on both Windows 2000 and XP. All I did was install
> > > the binaries from CRAN so I think I am using the standard Rblas.dll.
> > >
> > > To reproduce what I see you must run the code at the beginning of the
> > > R session.
> >
> >We did, as you said `start a clean session'.
> >
> >I think to reproduce what you see we have to be using your account on your
> >computer.
> >
> > > After the second run, all subsequent runs give the same
> > > result as the second set.
> > >
> > > Thanks,
> > > Francisco
> > >
> > >
> > > On Tue, 14 Sep 2004 08:29:25 +0200, Uwe Ligges
> > > <[EMAIL PROTECTED]> wrote:
> > > > Prof Brian Ripley wrote:
> > > > > I get the second set each time, on Windows, using the build from CRAN.
> > > > > Which BLAS are you using?
> > > >
> > > >
> > > > Works also well for me with a self compiled R-1.9.1 (both with standard
> > > > Rblas as well as with the Rblas.dll for Athlon CPU from CRAN).
> > > > Is this a NT-based version of Windows (NT, 2k, XP)?
> > > >
> > > > Uwe
> > > >
> > > >
> > > >
> > > >
> > > > > On Tue, 14 Sep 2004, Francisco Chamu wrote:
> > > > >
> > > > >
> > > > >>I start a clean session of R 1.9.1 on Windows and I run the
> > following code:
> > > > >>
> > > > >>
> > > > >>>library(MASS)
> > > > >>>data(painters)
> > > > >>>pca.painters <- princomp(painters[ ,1:4])
> > > > >>>loadings(pca.painters)
> > > > >>
> > > > >>Loadings:
> > > > >> Comp.1 Comp.2 Comp.3 Comp.4
> > > > >>Composition 0.484 -0.376 0.784 -0.101
> > > > >>Drawing 0.424 0.187 -0.280 -0.841
> > > > >>Colour -0.381 -0.845 -0.211 -0.310
> > > > >>Expression 0.664 -0.330 -0.513 0.432
> > > > >>
> > > > >> Comp.1 Comp.2 Comp.3 Comp.4
> > > > >>SS loadings 1.00 1.00 1.00 1.00
> > > > >>Proportion Var 0.25 0.25 0.25 0.25
> > > > >>Cumulative Var 0.25 0.50 0.75 1.00
> > > > >>
> > > > >>However, if I rerun the same analysis, the loadings of the first
> > > > >>component have the opposite sign (see below), why is that? I have
> > > > >>read the note
> > > > >>in the princomp help that says
> > > > >>
> > > > >> "The signs of the columns of the loadings and scores are arbitrary,
> > > > >> and so may differ between different programs for PCA, and even
> > > > >> between different builds of R."
> > > > >>
> > > > >>However, I still would expect the same signs for two runs in the
> > same session.
> > > > >>
> > > > >>
> > > > >>>pca.painters <- princomp(painters[ ,1:4])
> > > > >>>loadings(pca.painters)
> > > > >>
> > > > >>Loadings:
> > > > >> Comp.1 Comp.2 Comp.3 Comp.4
> > > > >>Composition -0.484 -0.376 0.784 -0.101
> > > > >>Drawing -0.424 0.187 -0.280 -0.841
> > > > >>Colour 0.381 -0.845 -0.211 -0.310
> > > > >>Expression -0.664 -0.330 -0.513 0.432
> > > > >>
> > > > >> Comp.1 Comp.2 Comp.3 Comp.4
> > > > >>SS loadings 1.00 1.00 1.00 1.00
> > > > >>Proportion Var 0.25 0.25 0.25 0.25
> > > > >>Cumulative Var 0.25 0.50 0.75 1.00
> > > > >>
> > > > >>>R.version
> > > > >>
> > > > >> _
> > > > >>platform i386-pc-mingw32
> > > > >>arch i386
> > > > >>os mingw32
> > > > >>system i386, mingw32
> > > > >>status
> > > > >>major 1
> > > > >>minor 9.1
> > > > >>year 2004
> > > > >>month 06
> > > > >>day 21
> > > > >>language R
> > > > >>
> > > > >>BTW, I have tried the same in R 1.9.1 on Debian and I can't reproduce
> > > > >>what I see
> > > > >>on Windows. In fact all the runs give the same as the second run
> > on Windows.
> > > > >>
> > > > >>-Francisco
> > > > >>
> > > > >>______________________________________________
> > > > >>[EMAIL PROTECTED] mailing list
> > > > >>https://stat.ethz.ch/mailman/listinfo/r-help
> > > > >>PLEASE do read the posting guide!
> > http://www.R-project.org/posting-guide.html
> > > > >>
> > > > >>
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >--
> >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
> >
> >______________________________________________
>
>
> >[EMAIL PROTECTED] mailing list
> >https://stat.ethz.ch/mailman/listinfo/r-help
> >PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
>
>
______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
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