Johannes Hüsing wrote: > Tom Backer Johnsen <[EMAIL PROTECTED]> [Fri, Jan 11, 2008 at 06:57:41PM CET]: > [...] >>> Are there something that can handle this in R? > > Have you considered the coin package?
I'll have a look at it. > >> After a few hours thinking on and off about the problem, I suspect >> that the question may be stupid or silly (or both). If that is the >> case, I would very much like to know why. >> > > I am not quite clear in my thinking anymore, but there are 2^2n > permutations, of which (2n choose n) happen to yield the same > effect. These cases are "part of life" and should be counted in > the permutation test just as well. You might save a little bit of > computation time by singling these group-preserving permutations > out, but this is not worth the while at all. ' Sure, but the question is simply: Do the permutations that only shuffle things within groups introduce some kind of a bias? I have a feeling that this is worse if the groups are not equally large. Tom > -- +----------------------------------------------------------------+ | Tom Backer Johnsen, Psychometrics Unit, Faculty of Psychology | | University of Bergen, Christies gt. 12, N-5015 Bergen, NORWAY | | Tel : +47-5558-9185 Fax : +47-5558-9879 | | Email : [EMAIL PROTECTED] URL : http://www.galton.uib.no/ | +----------------------------------------------------------------+ ______________________________________________ R-help@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.
