On Thu, 7 Feb 2008, jing hua zhao wrote: > > Dear R list, > > I calculated a two-sided p values according to 2*(1-pnorm(8.104474)), > which gives 4.440892e-16. However, it appears to be 5.30E-16 by a > colleague and 5.2974E-16 from SAS. I tried to get around with mvtnorm > package but it turns out to be using pnorm for univariate case. I should > have missed some earlier discussions, but for the moment is there any > short answer for a higher precision? Somehow these days, statistical > geneticists are infatuated with such tiny p values!
2*pnorm(8.104474, lower=FALSE) You can't find a small number accurately by subtraction: pnorm(8.104474) is being returned as the number the second smaller than one in IEC60559 arithmetic. > > Many thanks in advance, > > > Jing Hua > > _________________________________________________________________ > Telly addicts unite! > > [[alternative HTML version deleted]] > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
