Dear R-ers, I am currently running some Wilcoxon tests in R-64. How do I find the degrees of freedom in the output I am receiving?> wilcox.test(good$TRUE, good$x4a, paired=FALSE)Wilcoxon rank sum test with continuity correction data: good$TRUE and good$x4a W = 2455, p-value < 2.2e-16 alternative hypothesis: true location shift is not equal to 0 Thank you, Stephen. University of St Andrews, sm2284 at st-andrews.ac.uk -- View this message in context: http://r.789695.n4.nabble.com/Finding-the-Degrees-of-Freedom-in-a-Wilcoxon-Test-tp4650724.html Sent from the R help mailing list archive at Nabble.com.
On 25.11.2012 13:55, sm2284 wrote:> Dear R-ers, > > I am currently running some Wilcoxon tests in R-64. > > How do I find the degrees of freedom in the output I am receiving?You don't find any number related to degrees of freedom - which seems to be a bit out of context here? Uwe Ligges>> wilcox.test(good$TRUE, good$x4a, paired=FALSE) > > Wilcoxon rank sum test with continuity correction > > data: good$TRUE and good$x4a > W = 2455, p-value < 2.2e-16 > alternative hypothesis: true location shift is not equal to 0 > > > Thank you, > > Stephen. > > University of St Andrews, > sm2284 at st-andrews.ac.uk > > > > -- > View this message in context: http://r.789695.n4.nabble.com/Finding-the-Degrees-of-Freedom-in-a-Wilcoxon-Test-tp4650724.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. >
David Winsemius
2012-Nov-25 20:39 UTC
[R] Finding the Degrees of Freedom in a Wilcoxon Test
On Nov 25, 2012, at 4:55 AM, sm2284 wrote:> Dear R-ers, > > I am currently running some Wilcoxon tests in R-64. > > How do I find the degrees of freedom in the output I am receiving? > >> wilcox.test(good$TRUE, good$x4a, paired=FALSE) > > Wilcoxon rank sum test with continuity correction > > data: good$TRUE and good$x4a > W = 2455, p-value < 2.2e-16 > alternative hypothesis: true location shift is not equal to 0 >When using wilcox.test with two samples, the function passes some version of the Rank-Sum statistic W to the pwilcox function followed by the lengths of the two vectors. So I suppose you could say the sample sizes are the "degrees of freedom". Reasoning informally I would think the smaller of those lengths would be the most important in determining stability of the inference. BTW, methinks it a very questionable practice to name a column 'TRUE'. -- David Winsemius, MD Alameda, CA, USA