It looks like an example of FAQ 7.31 Why doesn't R think these numbers are equal?
John Kane Kingston ON Canada > -----Original Message----- > From: tomasb...@gmail.com > Sent: Wed, 15 Aug 2012 22:37:17 +1000 > To: r-help@r-project.org > Subject: [R] which() function not finding certain numbers > > Hi, > > I am using 32-bit R v 2.15.1, on Mac OsX v 10.6.8 with R GUI 1.52 Leopard > build 32-bit (6188). I have also replicated this error on R 2.13.2 on a > windows 7 machine. > > In some sequences of numbers, I am unable to use the which() function to > index certain values. It seems to be primarily numbers with a 3 in the > decimal. > For example: > >> S=seq(0,4,0.01) > >> which(S==2.02) > > [1] 203 > >> which(S==2.03) > > integer(0) > >> which(S==2.04) > > [1] 205 > >> which(S==2.04) > > [1] 205 > >> which(S==3.03) > > integer(0) > >> which(S==3.3) > > integer(0) > >> which(S==3.) > > [1] 301 > >> which(S==3.5) > > [1] 351 > >> > > I'm not even sure if this is a bug, or just some misunderstanding of the > seq() or which() functions, but any thoughts would be appreciated. > > TB > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ____________________________________________________________ FREE 3D MARINE AQUARIUM SCREENSAVER - Watch dolphins, sharks & orcas on your desktop! ______________________________________________ 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.
