On Tue, 2010-07-20 at 23:35 +0300, Jari Oksanen wrote: > On 20/07/10 22:42 PM, "Gavin Simpson" <gavin.simp...@ucl.ac.uk> wrote: > > > On Tue, 2010-07-20 at 12:12 -0700, Dragos Zaharescu wrote: > >> I would much appreciate if someone would enlighten me on how to calculate a > >> distance matrix based on correlation coefficient (Spearman)? The simple > >> correlation matrix seems not to work. > > > > >> 1 - cor(dat) ## dissimilarity > > > Actually the canonical transformation to distance is sqrt(2-2*cor(dat)). > > Cheers, Jari Oksanen
Of course, thanks Jari. That 1 - bit was total rubbish, not even acknowledging that cor could be negative. Not sure what came over me; I blame the heat here in London ;-) Hangs head in shame. G -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% _______________________________________________ R-sig-ecology mailing list R-sig-ecology@r-project.org https://stat.ethz.ch/mailman/listinfo/r-sig-ecology