On Tue, Jul 31, 2012 at 03:45:14PM -0400, Jie wrote: > Dear All, > > I am running a r code on 32bit win, involving absolutely small numbers. > Although I tried sth like the ratio of numers like 10^(-100) and did not > have issue to get the correct answer, > but still a little concerned about it. > Could anyone give some suggestion or have any experience?
Hi. Numbers of the order 10^(-100) are still relatively far from the lower limit and are represented with full precision, which is 53 bits. The smallest number representable in full precision is 2^-1022 = 2.225074e-308 and the smallest representable number (in limited precision) is 2^-1074 = 4.940656e-324. See http://en.wikipedia.org/wiki/Double_precision_floating-point_format for more detail. Hope this helps. Petr Savicky. ______________________________________________ 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.
