On Sat, 27 Aug 2005, Peter Dalgaard wrote: > Prof Brian Ripley <[EMAIL PROTECTED]> writes: > >> Check your versions of MASS. The Windows one appears to be an outdated >> version, and does different things. > > Forgetting to run tools/rsync-recommended during build will do that > sort of thing to you, but it would seem that Berwin used a binary > download. But of course he might be picking up an older version of the > package from a private library.
I think it is a case of the version released with 2.1.0 vs an update (possibly one post 2.1.1). >> As for the problem, yes it probably is a bug in L-BFGS-B. Fancy debugging >> the code? > > B. might just be capable of it, but this is certainly some of the more > impenetrable code in R. While he (or anyone else) is in there, there > seems to be another problem in that the Hessian calculations refuse to > stay within the bounds (which is pretty annoying when the objective > function is undefined outside of them). Try for instance > > f <- function(p) sum(ifelse(p>=-1e-4,p,Inf)^2) > optim(f, lower=c(0,0), par=c(5,5), method="L-BFGS-B") > optim(f, lower=c(0,0), par=c(5,5), method="L-BFGS-B", hess=T) I think you will find that is as documented: see the return value stated. Could be fixed though. ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
