many thanks for all the clarifications and for the declaration of intents for fixing qf(). For the sake of completeness I stumbled upon the behaviour of qf when preparing statistical tables with R to be put online for my students. I remained a bit surprised in seeing how much the results vary across textbooks at least for the F.
Kind regards Simone On Thu, Jun 5, 2008 at 5:13 PM, Prof Brian Ripley <[EMAIL PROTECTED]> wrote: > On Thu, 5 Jun 2008, Simone Giannerini wrote: > > Dear all, >> >> I found the following behaviour >> >> rf(5,Inf,Inf) >>> >> [1] 1 1 1 1 1 >> >> but >> >> qf(0.1,Inf,Inf) >>> >> [1] NaN >> Warning messages: >> 1: In qf(0.1, Inf, Inf) : value out of range in 'lgamma' >> 2: In qf(p, df1, df2, lower.tail, log.p) : NaNs produced >> > > Could do better here. > > incidentally, >> >> >> pf(1.00000000000001,Inf,Inf) >>> >> [1] 1 >> >>> pf(1.0000000000000001,Inf,Inf) >>> >> [1] 0.5 >> >> Is this the expected behaviour? >> > > I think so. 1.0000000000000001 is the same as 1 in computer arithmetic, and > pf(1, m, n) = 0.5 for all large m, n. > > >> Thanks >> >> Simone >> >> R.version >>> >> _ >> platform i386-pc-mingw32 >> arch i386 >> os mingw32 >> system i386, mingw32 >> status Patched >> major 2 >> minor 7.0 >> year 2008 >> month 04 >> day 22 >> svn rev 45451 >> language R >> version.string R version 2.7.0 Patched (2008-04-22 r45451) >> >> platform x86_64-unknown-linux-gnu >> arch x86_64 >> os linux-gnu >> system x86_64, linux-gnu >> status Patched >> major 2 >> minor 6.1 >> year 2008 >> month 01 >> day 17 >> svn rev 44036 >> language R >> version.string R version 2.6.1 Patched (2008-01-17 r44036) >> >> ______________________________________________________ >> >> Simone Giannerini >> Dipartimento di Scienze Statistiche "Paolo Fortunati" >> Universita' di Bologna >> Via delle belle arti 41 - 40126 Bologna, ITALY >> Tel: +39 051 2098262 Fax: +39 051 232153 >> http://www2.stat.unibo.it/giannerini/ >> ______________________________________________________ >> >> [[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/<http://www.stats.ox.ac.uk/%7Eripley/> > University of Oxford, Tel: +44 1865 272861 (self) > 1 South Parks Road, +44 1865 272866 (PA) > Oxford OX1 3TG, UK Fax: +44 1865 272595 > -- ______________________________________________________ Simone Giannerini Dipartimento di Scienze Statistiche "Paolo Fortunati" Universita' di Bologna Via delle belle arti 41 - 40126 Bologna, ITALY Tel: +39 051 2098262 Fax: +39 051 232153 http://www2.stat.unibo.it/giannerini/ ______________________________________________________ [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
