Hi. Easy. Regardless of OS and R version answer is binary representation of fractions.
> (4.2-4.1)>.1 [1] TRUE but > (4.3-4.2)>.1 [1] FALSE > print(4.3-4.2, digits=20) [1] 0.099999999999999645 You can not expect precise results using not precise computers. Use e.g. round > round(4.3-4.2)>.1 [1] FALSE HTH Petr On 1 Nov 2005 at 9:15, [EMAIL PROTECTED] wrote: To: [email protected] From: [EMAIL PROTECTED] Date sent: Tue, 1 Nov 2005 09:15:50 -0700 Subject: [R] Unexpected result from binary greater than operator > Hi All, > > I recently encountered results that I did not expect, exhibited by the > following code snippet: > > test <- function() { > minX <- 4.2 > min0 <- 4.1 > sigmaG <- 0.1 > Diff <- minX-min0 > print(c(Diff=Diff,sigmaG=sigmaG)) > cat("is Diff > sigmaG?:", Diff > sigmaG,"\n") > cat("is (4.2 - 4.1) > 0.1?:",(4.2 - 4.1) > 0.1,"\n") > cat("is 0.1 > 0.1?:", 0.1>0.1,"\n") > } > > When I execute the above function I get the following: > > test() > Diff sigmaG > 0.1 0.1 > is Diff > sigmaG?: TRUE > is (4.2 - 4.1) > 0.1?: TRUE > is 0.1 > 0.1?: FALSE > > Can someone please help me understand why R returns TRUE for (4.2 - > 4.1) > 0.1 ? > > Thanks so much, > Chris > > > I'm running the precompiled R-2.2.0 binary for Windows on WinXP Pro > SP1. > > >Sys.getlocale() > "LC_COLLATE=English_United States.1252;LC_CTYPE=English_United > States.1252;LC_MONETARY=English_United > States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252" > > >version > _ > platform i386-pc-mingw32 > arch i386 > os mingw32 > system i386, mingw32 > status > major 2 > minor 2.0 > year 2005 > month 10 > day 06 > svn rev 35749 > language R > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html Petr Pikal [EMAIL PROTECTED] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
