On Aug 23, 2011, at 12:21 PM, Jim Silverton wrote: > Hi everyone, > I have the following problem. I have some small p-values but when I use > > qnorm(1-4e-30) > I get an error. > Is there anyway to get around this?
Here is a hint: > qnorm(1 - 4e-30) [1] Inf > qnorm(1) [1] Inf # See ?all.equal > all.equal(1 - 4e-30, 1) [1] TRUE # See ?.Machine for more information > .Machine$double.eps [1] 2.220446e-16 Since 4e-30 is smaller than the above, you are essentially passing 1 to qnorm(). Try this: > qnorm(4e-30, lower.tail = FALSE) [1] 11.34337 See ?qnorm and avoid using the '1 - x' approach. HTH, Marc Schwartz ______________________________________________ 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.
