Hello, we have a large data set of water quality data and want to identify influence variables or *why* different groups of data are different (in an explorative sense). We consider to use biplots, however there are only the common PCA-Biplots available in R (biplot.princomp). We consider to use transformations (log-type, x^a, Box-Cox), but are seeking for alternatives. Are there experiences or comments about using something like a * PCA with rank-transformed data, * other transformations, or does anybody have * R-code to produce a biplot with MDS-like methods * or a suggestion for a "global alternative" method? Thank you in advance! Thomas Petzoldt -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._