thanks for your reply but, I am still confused what kind of centroids the 3x4 matrix represents. In fact, I passed that 3x4 centers matrix as the initial centers to kkmeans method and I am getting the error "Error in crossprod(x[vgr[[i]], vgr[[i]], drop = FALSE], w[vgr[[i]]]) : object 'vgr' not found"
--ahmed On Wed, Apr 3, 2013 at 10:30 AM, Pascal Oettli <kri...@ymail.com> wrote: > Hi, > > The output of the provided example shows you which kind of matrix you need > for cluster centers. In the example, 3 centers per variable (4) are > defined. Thus, the initial cluster centers are defined by a 3x4 matrix. > > HTH, > Pascal > > ------------------------------ > *De :* Ahmed Elgohary <aagoh...@gmail.com> > *À :* r-help@r-project.org > *Cc :* Pascal Oettli <kri...@ymail.com> > *Envoyé le :* Mercredi 3 avril 2013 22h53 > *Objet :* Re: [R] kernlab::kkmeans initial centers > > I am not asking about k-means. I am asking about passing initial > assignments to the kernel k means algorithm. In kernel k-means, centroids > are not defined explicitly. I tried passing initial centroids in the > original feature space though. But, it did not work. The provided example > just sets the number of clusters and lets the method assigns random cluster > memberships. I am also wondering about the output centers. Are they the > centers in the eigenvectors space? If so, what kind of initial centers I am > supposed to pass to the method? > > --ahmed > > On Wed, Apr 3, 2013 at 12:54 AM, Pascal Oettli <kri...@ymail.com> wrote: > > Hi, > > I would say that if you know what k-means algorithm is, you know the > meaning of "initial cluster centers". > > You can also check the output of the provided example. > > Regards, > Pascal > > > On 04/03/2013 09:27 AM, Ahmed Elgohary wrote: > > Hi, > > I am trying to pass initial cluster assignments to the kkmeans > method<http://rss.acs.unt.edu/**Rdoc/library/kernlab/html/**kkmeans.html<http://rss.acs.unt.edu/Rdoc/library/kernlab/html/kkmeans.html> > >of > > kernlab. It is not clear to me how I can set the parameter > *centers* with "initial cluster centers" as stated in the documentation? > > thanks, > > --ahmed > > [[alternative HTML version deleted]] > > ______________________________**________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/**listinfo/r-help<https://stat.ethz.ch/mailman/listinfo/r-help> > PLEASE do read the posting guide http://www.R-project.org/** > posting-guide.html <http://www.r-project.org/posting-guide.html> > and provide commented, minimal, self-contained, reproducible code. > > > > > [[alternative HTML version deleted]]
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