There is a documented bug in R 2.15.2 and R 2.15.3. The developers decided not to fix this with an update, but it has been fixed with R 3.0.0 (perhaps also with R 3.0.1, which I have not tried myself). So, upgrading R should take care of this problem.
HTH, Ranjan On Sun, 19 May 2013 16:17:30 +0200 Luca Nanetti <luca.nane...@gmail.com> wrote: > Dear Simon, > > I respectfully disagree with you, when you say that it is NOT a bug. Empty > clusters can only happen if one provides a set of centers; if one enters > something like k=4, it cannot happen, so it must be a bug. Which one is > your case? > >From the help: > > "Except for the Lloyd-Forgy method, k clusters will always be returned if a > number is specified. If an initial matrix of centres is supplied, it is > possible that no point will be closest to one or more centres, which is > currently an error for the Hartigan-Wong method" > > This having been said, I suspect that there is a bug in the current > implementation of kmeans. I get the "empty cluster: try ..." answer even > when I enter a number of clusters, but only with R 2.15. I never had it > with R 2.14. Didn't try with R 3, yet. > I posted this problem on the list twice, at no avail (unless I forgot to > find the answer in the mailing list, of course). > > Kind regards, > Luca > > > Hello all, > > > k-means algorithms can at times fail because one of the cluster become > > emmpty. In this case, the kmeans R function returns: > >"empty cluster: try a better set of initial centers" > > > This has been discussed several times on several R-lists, and is NOT a > > bug, but can be annoying when using k-means in complex simulation where > > this error brings everything to a stop. One can use try() or tryCatch() > > to avoid this, but this is just a programming trick. > > -- > ______________ > > Luca Nanetti, MSc, MRI > University Medical Center Groningen > Neuroimaging Center Groningen > Groningen, The Netherlands > Tel: +31 50 363 4733 > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Important Notice: This mailbox is ignored: e-mails are set to be deleted on receipt. For those needing to send personal or professional e-mail, please use appropriate addresses. ____________________________________________________________ FREE 3D EARTH SCREENSAVER - Watch the Earth right on your desktop! ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.