Tks for your help, after investigate in your link, i find there seems three ways can be adoped: 1. is.wholenumber <- function(x, tol = .Machine$double.eps^0.5) abs(x - round(x)) < tol) e.g. is.wholenumber(1) 2. x%%1==0
3. all.equal(a, as.integer(a)) and also included your last suggestion using floor. and also tks for other helpers! -- PO SU mail: desolato...@163.com Majored in Statistics from SJTU At 2014-10-18 22:48:15, "Sergio Fonda" <sergio.fond...@gmail.com> wrote: Sorry for my previous hurry misunderstanding. Try this link: http://stackoverflow.com/questions/3476782/how-to-check-if-the-number-is-integer 2014-10-18 16:25 GMT+02:00 PO SU <rhelpmaill...@163.com>: It's due to that, 1 is a numeric, 1.2 is a numeric, though it's true. but deeply, when i want to know 1 is an integer, there seems no easy way to get the answer. So, is there anyone happen to know it? -- PO SU mail: desolato...@163.com Majored in Statistics from SJTU At 2014-10-18 20:10:09, "S Ellison" <s.elli...@lgcgroup.com> wrote: >> But i use a<-10/b , b is some value ,may be 5, maybe 5.5 >If you do floating point arithmetic on integers you'll usually get floating >point answers, including the 5.0. > >See FAQ 7.31 for the usual floating point problem, and ?all.equal for the >usual answer to it. You could see if a result is close to an integer by,for >example, using all.equal to compare it to itself after rounding. > >S > >******************************************************************* >This email and any attachments are confidential. Any use, copying or >disclosure other than by the intended recipient is unauthorised. If >you have received this message in error, please notify the sender >immediately via +44(0)20 8943 7000 or notify postmas...@lgcgroup.com >and delete this message and any copies from your computer and network. >LGC Limited. Registered in England 2991879. >Registered office: Queens Road, Teddington, Middlesex, TW11 0LY, UK ______________________________________________ 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.