Something strange in cor.test in R-1.8.0 (PR#4718)
Peter Dalgaard writes:
Kurt Hornik <Kurt.Hornik@wu-wien.ac.at> writes:
maechler writes:
"Duncan" == Duncan Murdoch <dmurdoch@pair.com>
on Wed, 22 Oct 2003 08:17:32 -0400 writes:
Duncan> I've now tried the code
set.seed(1) x <- rnorm(50) y <- rnorm(50) cor.test(x,y,method="spearman") x <- rnorm(50) y <- rnorm(50) cor.test(x,y,method="spearman")
Duncan> in r-patched (which gives apparently correct results), and r-devel, Duncan> which gives the first result correct, the second incorrect; when Duncan> repeated, both are bad.
Hmm, funny.
I get repeatable results in in R 1.7.1 , 1.8.0, R-patched and R-devel (all on Linux),
with an (ugly but convenient) 1-liner :
set.seed(1); for(k in 1:2){x <- rnorm(50);y <- rnorm(50);print(unlist(cor.test(x,y,method="spearman")[1:4]))}
statistic.S p.value estimate.rho 23640.0000000 0.3482088 -0.1351741 statistic.S p.value estimate.rho 1.724800e+04 2.322263e-01 1.717647e-01
I get the same on Debian GNU/Linux. Where do we stand on this? Windows-specific?
Probably, but of a nasty kind which I think we need to get to the bottom of. As I see it there are two possible causes
1. A bug in a Windows library or compiler. Potentially that could affect everything else. 2. A bug in ctest that just happens only to cause visible damage on Windows, but perhaps invisible damage elsewhere.
Either way, I think we need to investigate.
As Brian had written earlier in this thread, we need a reproducible example. If Duncan's example can be reproduced on Windows but not on Linux (and I cannot), odds are in favor of the problem being Windows specific. -k