On Fri, Oct 27, 2006 at 11:14:25AM +0200, Jens Oehlschl?gel wrote: > rather, but in fact NAs seem to be always treated ties.method = > "first". I have no idea in which situation one could desire > e.g. ties.method = "average" except for NAs!?
Interesting. I was aware of the S-Plus vs. R difference, but I didn't realize that it appears to be because R rank() ignores ties.method="average" for NA values. > I am aware that the prototype behaves like this and R ever since > behaves like this, however to me this appears very unfortunate. In > order not to 'break' existing code, what about adding ties.methods If you only care about ranking integers and floating point numbers, it's pretty straghtforward to take the S-Plus implementation of rank(), call it to my.rank(), and use it in both R and S-Plus. (Since the R rank() makes calls to .Internal(), you can't re-use its implementation in S-Plus.) Note though that the S-Plus-style my.rank() will still sort strings differently in R than in S-Plus. I never looked into why. Some old notes I have on this issue: R and S-Plus rank() treat NAs differently (which can magnifiy other floating point differences): # S-Plus 6.2.1: # R 2.1.0: > rank(1:5) > rank(1:5) [1] 1 2 3 4 5 [1] 1 2 3 4 5 > rank(c(1,2,NA,4,NA)) > rank(c(1,2,NA,4,NA)) [1] 1.0 2.0 4.5 3.0 4.5 [1] 1 2 4 3 5 > rank(c(1,NA,3,4,NA)) > rank(c(1,NA,3,4,NA)) [1] 1.0 4.5 2.0 3.0 4.5 [1] 1 4 2 3 5 > rank(c(1,NA,3)) > rank(c(1,NA,3)) [1] 1 3 2 [1] 1 3 2 > rank(c(NA,NA,3)) > rank(c(NA,NA,3)) [1] 2.5 2.5 1.0 [1] 2 3 1 -- Andrew Piskorski <[EMAIL PROTECTED]> http://www.piskorski.com/ ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel