Ummm... I think the "problem" is with _your_ inadequate understanding.
Consider: identical( (4.1 * 100 ) %/% 1 , 409 ) > 4.1*100 < 410 [1] TRUE So, due to finite precision, 4.1*100 is slightly less than 410. Whence the largest integer 1 can be divided into it is 409. i.e. > (4.1*100) %/% 1 [1] 409 ?"%/%" Bert Gunter Genentech Nonclinical Statistics -----Original Message----- From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On Behalf Of JustinNabble Sent: Tuesday, April 06, 2010 2:27 PM To: r-help@r-project.org Subject: Re: [R] Odd results with %% and conserving memory Thanks for the response. I read through the Inferno and there's a lot of useful stuff in there. However I think you may have missed something. Having some experience with other languages, I know that floating point numbers aren't represented exactly, the issue is that R is off by much more than would be expected. On my computer, cell 9,2 of (mat * 100) %% 1 is larger than .99 and the correct result is 0. That difference seems too large to be a problem with representing floating point numbers. Likewise, identical( (4.1 * 100 ) %/% 1 , 409 ) returns TRUE on my computer, so the result is off by exactly 1, too larger to be explained by floating point error. I think there's a problem with how the %% and %/% operators are getting their results. -- View this message in context: http://n4.nabble.com/Odd-results-with-and-conserving-memory-tp1692845p175354 0.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
