On Fri, 4 Nov 2005, Ben Bolker wrote: > > There's an apparent inconsistency between the > behavior of d(pqr)gamma and other distribution > functions for "bad" parameter values. Specifically, > most distributions give NaN and a warning for bad > parameters (e.g. probabilities <0 or >1). In contrast, > d(pqr)gamma actually gives an error and stops when shape<0. > I don't see why it has to be this way -- the internal > C code is set up to detect shape<0 (or scale<0) and > return NaN and a warning, and none of the other > distribution functions in that bit of the code have > similar behavior. > > It would seem more consistent (and would be more > convenient for me -- the error-instead-of-warning > is making me have to jump through additional hoops) > if dgamma just returned NaN and a warning. > > Any thoughts?
No one has come up with any, so let us remove the errors in R-devel. Note that rgamma is not protected at C level: try rgamma(10, -2), or (worse) rgamma(10, -20) after removing the stop() call. -- 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
