On Wed, 2009-03-18 at 11:58 -0400, Yu, Changhong wrote: > Dear all, > > > > I am totally confused by the following R output, but don't have a clue > for it. > > > > > a <- 1 - 0.2 > > > a == 0.8 > > [1] TRUE > > > a <- 1 - 0.8 > > > a == 0.2 > > [1] FALSE
Hi Yu, First of all read FAQ 7.31 (Why doesn't R think these numbers are equal?) Second, in this case, use all.equal a <- 1 - 0.8 a == 0.2 [1] FALSE all.equal(a,0.2) [1] TRUE -- Bernardo Rangel Tura, M.D,MPH,Ph.D National Institute of Cardiology Brazil ______________________________________________ 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.