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. 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 > >> > >> > > > > > > ______________________________________________ [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
