glaporta <glaporta <at> freeweb.org> writes: > > Dear list, > I read the SOM package manual but I don't understand how to perform (for > example) 1) the SOM analysis on Iris data 2) with a visualization similar to > that of figure 7 in > http://www.cis.hut.fi/projects/somtoolbox/package/papers/techrep.pdf
In R, I used the following calls to create SOM maps similar to the ones in the literature (I don't find the SOM toolbox figures particularly inspiring): ---- library("class") data(iris) n <- 10 sg <- somgrid(n, n, "rectangular") df.som <- batchSOM(df, sg, c(4,4,3,3,2,2,1,1)) windows(record=TRUE) for (i in 1:ncol(df)) { xy <- matrix(df.som$codes[,i], n, n) image(xy) contour(xy, add=T) grid(col="gray") } ---- Of course, there are not enough Iris data to generate a reasonable SOM grid. At least n <- 30 is needed for a nice graph, and that means at least 1000 data points. Using a Binhex grid instead of a rectangular one will result in diagrams similar to those from the SOM toolbox. But then the 'image' call has to be a bit prepared for this. Regards, Hans Werner > Any suggestion? Thanks in advance, > Gianandrea ______________________________________________ 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.