Dear R-users, I have a two - dimensional data set which needs to be clustered into groups: I'm searching for groups of points which show a positive correlation (in a twodimensional plot of the data set), but I do not have any knowledge about how many groups there might be. Do you know of a clustering algorithm in R (or in general) which can use a-priori information about the cluster's shape, in particular that the points of a given cluster should lie on a line? The "EMclust" algorithm does allow to chose a general shape, such as "elliptical" for example. However, this method proved not to be successful. Thank you very much, Yours sincererly Philip
clustering
2 messages · EdwardSeelefant@aol.com, Christian Hennig
Dear Philip, as you have already suggested, mclust would be the first choice. Did you try to run EMclust with emModelNames="VEV"? If you send me the data, I can take a look at it and see what went wrong. There is also methodology for clusterwise linear regression (CLR), where the points of a cluster lie on a line, but there is a distinction between dependent and independent variable, which may or may not be what you want. As far as I know, there is nothing for CLR on CRAN, but my R-package fpc contains a function fixreg for linear regression fixed point clusters (reference Hennig, Journal of Classification 19, 249-276 (2002)). It can be obtained under http://www.math.uni-hamburg.de/home/hennig/fixreg/fixreg.html Furthermore I have a program for ML-estimation of linear regression mixtures (reference deSarbo and Cron, Journal of Classification 5, 249-282 (1988)), but undocumented and for private use. Ask me if you are interested. Best, Christian
On Wed, 23 Apr 2003 EdwardSeelefant at aol.com wrote:
Dear R-users, I have a two - dimensional data set which needs to be clustered into groups: I'm searching for groups of points which show a positive correlation (in a twodimensional plot of the data set), but I do not have any knowledge about how many groups there might be. Do you know of a clustering algorithm in R (or in general) which can use a-priori information about the cluster's shape, in particular that the points of a given cluster should lie on a line? The "EMclust" algorithm does allow to chose a general shape, such as "elliptical" for example. However, this method proved not to be successful. Thank you very much, Yours sincererly Philip
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*********************************************************************** Christian Hennig Seminar fuer Statistik, ETH-Zentrum (LEO), CH-8092 Zuerich (currently) and Fachbereich Mathematik-SPST/ZMS, Universitaet Hamburg hennig at stat.math.ethz.ch, http://stat.ethz.ch/~hennig/ hennig at math.uni-hamburg.de, http://www.math.uni-hamburg.de/home/hennig/ ####################################################################### ich empfehle www.boag.de