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
