Here is what I get on a Windows with r2.71 > x <- 0.55 > 100*x - 55 [1] 7.105427e-15 > y <- 2.55 > 100*y - 255 [1] -2.842171e-14 > round(x,1) [1] 0.6 > round(y,1) [1] 2.5 >
On Thu, Jul 10, 2008 at 9:10 PM, Moshe Olshansky <[EMAIL PROTECTED]> wrote: > Actually, your result is strange, since if x = 0.55 then a hexadecimal > representation of x*100 is 404B8000 00000001 which is above 55, meaning that > x is above 0.55 and should have been rounded to 0.6, while if x = 2.55 then > the hexadecimal representation of x*100 is 406FDFFF FFFFFFFF which is below > 255, so that x is less than 2.55 and should have been rounded to 2.5. > > > --- On Fri, 11/7/08, Moshe Olshansky <[EMAIL PROTECTED]> wrote: > >> From: Moshe Olshansky <[EMAIL PROTECTED]> >> Subject: Re: [R] rounding >> To: [EMAIL PROTECTED], "Korn, Ed (NIH/NCI) [E]" <[EMAIL PROTECTED]> >> Received: Friday, 11 July, 2008, 10:39 AM >> The problem is that neither 0.55 nor 2.55 are exact machine >> numbers (the computer uses binary representation), so it >> may happen that the machine representation of 0.55 is >> slightly less than 0.55 while the machine representation of >> 2.55 is slightly above 2.55. >> >> >> --- On Fri, 11/7/08, Korn, Ed (NIH/NCI) [E] >> <[EMAIL PROTECTED]> wrote: >> >> > From: Korn, Ed (NIH/NCI) [E] >> <[EMAIL PROTECTED]> >> > Subject: [R] rounding >> > To: [EMAIL PROTECTED] >> > Received: Friday, 11 July, 2008, 6:07 AM >> > Hi, >> > >> > Round(0.55,1)=0.5 >> > >> > Round(2.55,1)=2.6 >> > >> > Can this be right? >> > >> > Thanks, >> > >> > Ed >> > >> > [[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. >> >> ______________________________________________ >> 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. > -- Jim Holtman Cincinnati, OH +1 513 646 9390 What is the problem you are trying to solve? ______________________________________________ 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.
