I find it helpful to explain to my colleagues from non-mathematical background that in classification the classes are predefined and in clustering the classes (and sometimes the number of classes) are not.
I prefer the use of the term "class discovery" over clustering when people try to cluster samples in order to derive meaningful classes. Regards, Adai On Wed, 2006-03-29 at 18:52 -0500, Liaw, Andy wrote: > In addition to Brian's comment, Gordon's book, already in 2nd edition, is > all about clustering, but the title is simply `Classification'. > > Andy > > From: Sean Davis > > > > We have to be careful here. Classification (which is the > > terminology that the original poster used) is NOT the same as > > clustering, although the two are often confused. If the > > original poster wants to do clustering and examine the > > results for the presence of three clusters, that is fine and > > there are many methods for clustering that could be used. > > However, classification will require a different set of > > tools. If the clustering tools already pointed out are not > > doing what is needed (that is, that Cao actually is > > interested in clustering and not classification), then > > perhaps a further explanation of what the problem would help clarify. > > > > Sean > > > > > > On 3/29/06 1:46 AM, "Jacques VESLOT" <[EMAIL PROTECTED]> wrote: > > > > > try this (suppose mat is your matrix): > > > > > > hc <- hclust(dist(mat,"manhattan"), "ward") > > > plot(hc, hang=-1) > > > (x <- identify(hc)) # rightclick to stop > > > cutree(hc, 3) > > > > > > km<- kmeans(mat, 3) > > > km$cluster > > > km$centers > > > > > > pam(daisy(mat, metric = "manhattan"), k=3, diss=T)$clust > > > > > > > > > > > > Baoqiang Cao a écrit : > > > > > >> Thanks! > > >> I tried kmeans, the results is not very positive. Anyway, thanks > > >> Jacques! Please let me know if you have any other thoughts! > > >> > > >> Best regards, > > >> Baoqiang Cao > > >> > > >> ======= At 2006-03-29, 00:08:44 you wrote: ======= > > >> > > >> > > >> > > >>> if you want to classify rows or columns, read: > > >>> ?hclust > > >>> ?kmeans > > >>> library(cluster) > > >>> ?pam > > >>> > > >>> > > >>> Baoqiang Cao a écrit : > > >>> > > >>> > > >>> > > >>>> Dear All, > > >>>> > > >>>> I have a data, suppose it is an N*M matrix data. All I > > want is to > > >>>> classify it into, let see, 3 classes. Which method(s) do > > you think > > >>>> is(are) appropriate for this purpose? Any reference will be > > >>>> welcome! Thanks! > > >>>> > > >>>> Best, > > >>>> Baoqiang Cao > > >>>> > > >>>> > > >>>> > > >>>> > > ------------------------------------------------------------------- > > >>>> ----- > > >>>> > > >>>> ______________________________________________ > > >>>> R-help@stat.math.ethz.ch mailing list > > >>>> https://stat.ethz.ch/mailman/listinfo/r-help > > >>>> PLEASE do read the posting guide! > > >>>> http://www.R-project.org/posting-guide.html > > >>>> > > >>>> > > >>>> > > >>> . > > >>> > > >>> > > >> > > >> = = = = = = = = = = = = = = = = = = = = > > >> > > >> Baoqiang Cao > > >> [EMAIL PROTECTED] > > >> 2006-03-29 > > >> > > >> > > >> > > >> > > > > > > ______________________________________________ > > > R-help@stat.math.ethz.ch mailing list > > > https://stat.ethz.ch/mailman/listinfo/r-help > > > PLEASE do read the posting guide! > > > http://www.R-project.org/posting-guide.html > > > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > > > > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html