Randomization tests, grouped data

Tom Backer Johnsen <backer at psych.uib.no> [Fri, Jan 11, 2008 at 06:57:41PM CET]:
[...]

Are there something that can handle this in R?

Have you considered the coin package?

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.

Johannes H?sing               There is something fascinating about science. 
                              One gets such wholesale returns of conjecture 
mailto:johannes at huesing.name  from such a trifling investment of fact.                
http://derwisch.wikidot.com         (Mark Twain, "Life on the Mississippi")