First of all, kmeans doesn't work on distance matrices. On Mon, 7 Aug 2006, Ffenics wrote:
> Hi there > I have been using R to perform kmeans on a dataset. The data is fed in using > read.table and then a matrix (x) is created > > i.e: > > [ > mat <- matrix(0, nlevels(DF$V1), nlevels(DF$V2), > dimnames = list(levels(DF$V1), levels(DF$V2))) > mat[cbind(DF$V1, DF$V2)] <- DF$V3 > This matrix is then taken and a distance matrix (y) created using dist() > before performing the kmeans clustering. > > My query is this: not all the data for the initial matrix (x) exists and > therefore the matrix is not fully populated - empty cells are populated with > '0's. > > Could someone please tell me how this may affect the result from the dist() > command - because a '0' in a distance matrix means that the two variables are > identical doesnt it(?) - but I dont want tthings clustered together simply > because there was no information. > > Is this a problem and are there ways to circumnavigate them? Thanks > > [[alternative HTML version deleted]] > > ______________________________________________ > [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 > and provide commented, minimal, self-contained, reproducible code. > *** --- *** Christian Hennig University College London, Department of Statistical Science Gower St., London WC1E 6BT, phone +44 207 679 1698 [EMAIL PROTECTED], www.homepages.ucl.ac.uk/~ucakche ______________________________________________ [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 and provide commented, minimal, self-contained, reproducible code.
