On Mon, 30 Jan 2006, Jacques VESLOT wrote: > sorry if it has already been discussed but i can't understand this: > > > seq(0.1,1,by=0.1) > [1] 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 > > match(0.1,seq(0.1,1,by=0.1)) > [1] 1 > > match(0.2,seq(0.1,1,by=0.1)) > [1] 2 > > match(0.3,seq(0.1,1,by=0.1)) > [1] NA > > match(0.4,seq(0.1,1,by=0.1)) > [1] 4
FAQ 7.31 http://cran.r-project.org/doc/FAQ/R-FAQ.html#Why-doesn_0027t-R-think-these-numbers-are-equal_003f > print(seq(0.1,1,by=0.1), digits=20) [1] 0.10000000000000000555 0.20000000000000001110 0.30000000000000004441 [4] 0.40000000000000002220 0.50000000000000000000 0.59999999999999997780 [7] 0.70000000000000006661 0.80000000000000004441 0.90000000000000002220 [10] 1.00000000000000000000 > match(c(0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9), seq(0.1,1,by=0.1)) [1] 1 2 NA 4 5 6 NA 8 9 > all.equal(c(0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0), seq(0.1,1,by=0.1), + tolerance = .Machine$double.eps ^ 2) [1] "Mean relative difference: 1.665335e-16" > all.equal(c(0.1,0.2,0.3,0.4,0.5,0.6,0.7,0.8,0.9,1.0), seq(0.1,1,by=0.1)) [1] TRUE > > > R.version > _ > platform i386-pc-mingw32 > arch i386 > os mingw32 > system i386, mingw32 > status > major 2 > minor 2.1 > year 2005 > month 12 > day 20 > svn rev 36812 > language R > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > -- Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 95 43 e-mail: [EMAIL PROTECTED] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html