On Jun 28, 2012, at 22:49 , <michael.bau...@contrib.scilab.org> <michael.bau...@contrib.scilab.org> wrote:
> Hi, > > With R version 2.10.0 (2009-10-26) on Windows, I computed the p=1.e-20 > quantile of the geometric distribution with parameter prob=0.1. > >> qgeom(1.e-20,0.1) > [1] -1 > > But this is not possible, since X=0,1,2,... > > I guess that this might be a bug in the quantile function, which should use > the log1p function, instead of the naive formula. > > Am I correct ? Nope. (The source is availably, you know....). The problem is that a slight fuzz is subtracted inside ceil(....), but there's no check that the result is positive. qnbinom(...., size=1) is equivalent and does get right, by the way. -pd > > Best regards, > > Michaël > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
