Try reading the man page, which says: Details
When ties.method = "random", as per default, ties are broken at random. In this case, the determination of a tie assumes that the entries are probabilities: there is a relative tolerance of 1e-5, relative to the largest (in magnitude, omitting infinity) entry in the row. Bert Gunter Genentech Nonclinical Biostatistics -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of Daryl Morris Sent: Thursday, May 28, 2009 1:47 PM To: r-help@r-project.org Subject: [R] max.col weirdness Hi, I think there's some rounding issue with returning the max column. (running 2.9.0 on an Apple, but my buddy found it on his PC) > x <- matrix(c(1234.568,1234.569,1234.567),1) > max.col(x) [1] 2 > x <- matrix(c(12345.568,12345.569,12345.567),1) > max.col(x) [1] 3 > x <- matrix(c(112345.568,112345.569,112345.567),1) > max.col(x) [1] 3 > max.col(-x) [1] 1 Thanks, Daryl ______________________________________________ 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. ______________________________________________ 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.
