Dear all, as far as my understanding goes, isoMDS uses the Kruskal definition of stress, i.e. : "the square root of the ratio of the sum of squared differences between the input distances and those of the configuration to the sum of configuration distances squared." (as stated in the help files). Now the definition of Kruskal also includes weights. I checked the isoMDS code, but they call to C routines that I can't really read. Anybody an idea about whether or not isoMDS applies those weights? Next to that, "The input distances are allowed a monotonic transformation. " How do I have to see that transformation within isoMDS? Kind regards Joris -- Joris Meys Statistical Consultant Ghent University Faculty of Bioscience Engineering Department of Applied mathematics, biometrics and process control Coupure Links 653 B-9000 Gent tel : +32 9 264 59 87 Joris.Meys@Ugent.be ------------------------------- Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php [[alternative HTML version deleted]]