Note: this procedure assumes that all clusters have the same covariance matrix.
albyn On Wed, Mar 03, 2010 at 01:23:37PM -0800, Phil Spector wrote: > The manhattan distance and the Mahalanobis distances are quite different. > One of the main differences is that a covariance matrix is necessary to > calculate the Mahalanobis > distance, so it's not easily accomodated by dist. There is a function in > base R which does calculate the Mahalanobis > distance -- mahalanobis(). So if you pass a distance matrix > calculated by mahalanobis() to the clustering function, you'll > get what you want. > - Phil Spector > Statistical Computing Facility > Department of Statistics > UC Berkeley > spec...@stat.berkeley.edu > > > On Wed, 3 Mar 2010, Tal Galili wrote: > >> when you create the distance function to put into the hclust, use: >> >> dist(x, method = "manhattan") >> >> >> Tal >> >> >> >> ----------------Contact >> Details:------------------------------------------------------- >> Contact me: tal.gal...@gmail.com | 972-52-7275845 >> Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | >> www.r-statistics.com (English) >> ---------------------------------------------------------------------------------------------- >> >> >> >> >> On Wed, Mar 3, 2010 at 9:14 PM, naama <nw...@technion.ac.il> wrote: >> >>> >>> How can I perform cluster analysis using the mahalanobis distance instead >>> of >>> the euclidean distance? >>> thank you >>> Naama Wolf >>> >>> -- >>> View this message in context: >>> http://n4.nabble.com/cluster-with-mahalanobis-distance-tp1577038p1577038.html >>> Sent from the R help mailing list archive at Nabble.com. >>> >>> ______________________________________________ >>> 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. >>> >> >> [[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. >> > > ______________________________________________ > 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. > ______________________________________________ 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.
