See, e.g. http://en.wikipedia.org/wiki/Double-precision_floating-point_format
Also in ?print.default please note: Large number of digits Note that for large values of digits, currently for digits >= 16, the calculation of the number of significant digits will depend on the platform's internal (C library) implementation of sprintf() functionality. -- Bert On Mon, May 20, 2013 at 6:06 PM, Xiao He <praguewaterme...@gmail.com> wrote: > Dear R-users: > > Hi, I read here ( > http://stackoverflow.com/questions/2287616/controlling-digits-in-r) that R > is only accurate up to the 15th decimal place, despite the fact that if you > choose to display more decimal places, it will. I wonder if R uses the > information beyond the 15th decimal place in actual computation. Thanks! > > > Best, > Xiao > > [[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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.