On Tue, Oct 20, 2009 at 8:14 AM, Ted Harding <ted.hard...@manchester.ac.uk> wrote: > On 20-Oct-09 13:34:49, Peng Yu wrote: >> fisher.test() gives a very small p-value, which is underflow on my >> machine. However, the log of it should not be underflow. I'm wondering >> if there is a way get log() of a small p-value. An approximation is >> acceptable in this case. Thank you! >> >>> fisher.test(rbind(c(10000,100000),c(100000,10000000)))$p.value >> [1] 0 > > I have not attempted an exact approach (though may do so later), > but the P-value in question is about 1e-15000 so (using log to > base e) > > log(P) approx = -33000 > > In such a case, P=0 is a pretty good approximation! > > Which prompts the question: Why the interest in having the value > of such a very small number?
Is there any existing method that could return a log() of a very small p-value? ______________________________________________ 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.
