Andrew Yee wrote: > Pardon my ignorance, but is there a difference in cor.test between > exact=FALSE and exact=NULL when method=spearman? > > Take for example: > > x<-c(1,2,2,3,4,5) > y<-c(1,2,2,10,11,12) > cor.test(x,y, method="spearman", exact=NULL) > > This gives an error message, > Warning message: Cannot compute exact p-values with ties in: > cor.test.default(x, y, method = "spearman", exact = NULL) > > However, when exact is changed to FALSE, this seems to run okay. > > cor.test(x,y, method="spearman", exact=FALSE) > > Question: should this be exact = FALSE in the documentation and/or the code? > > No. The default is indeed NULL.
This implies that calculation of exact p-values will be attempted, and when there are ties you get a warning (NB: not error) message. Setting exact=FALSE, no attempt is made and no warning is given. > Thanks, > Andrew > MGH Cancer Center > > ______________________________________________ > 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 > and provide commented, minimal, self-contained, reproducible code. > -- 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 and provide commented, minimal, self-contained, reproducible code.
