[EMAIL PROTECTED] writes: > Hello, > > Does anyone know if the cor function, when method = "spearman", returns a > correlation coefficient corrected for any ties in the ranks of the data? I > have data with quite a few ties and am thinking that I should use a > calculation of the coefficient corrected for ties, but before I try and code > this calculation myself, I thought I should check whether or not cor() > automatically does this. > > Thank you! > Joanna McGarvie
The tie-corrected spearman correlation is the correlation of the tie-corrected ranks, so yes, it does do that. Previous versions of R had an issue with p-values in cor.test, where it used the exact distribution of the test for non-tied data, even when ties were present. This was straightened out in 2.2.0, where it now uses an asymptotic formula instead. -- O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
