Hi Sarah, sorry for the lack of details..hope now my dilemma will be clearer: so, I have my dataset, represented by a matrix:100 subjects and 20 variables, expressed as 1(presence) and 0 (absence) I then tried to obtain a dissimilarity m. using the jaccard() command. To perform a NMDS, I used the isoMDS() command from the vegan package, specifying k=2 dimensions.
The returned error sentence says that I have "0 or negative" distance between some subjects (and that's true, a lot have an identical expression of each variable). adding zerodist="ignore" in isoMDS does not solve the problem: same message. So: this is the blind alley. thanks for any feedback marco -- View this message in context: http://r.789695.n4.nabble.com/Dichotomous-variables-tp3721550p3724639.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.
