Thank you, will be fixed in the next release of nlme (not yet scheduled, as everythign is code frozen for the release of R 2.5.1 tomorrow).
On Tue, 26 Jun 2007, Andrzej Galecki wrote: > > Two attachments: > > 1. getVarCovBugReport.R - Rcode with an example illustrating the problem and > how to fix it > 2. getVarCovBugReportSession.txt contains code and R session results. > > Thank you > > Andrzej Galecki > > > > Prof Brian Ripley wrote: > >> On Mon, 25 Jun 2007, [EMAIL PROTECTED] wrote: >> >>> I am using R2.5 under Windows. >> >> >> I presume you mean 2.5.0 (there is no R2.5: see the posting guide). But >> which version of nlme, which is the relevant fact here? The R posting >> guide suggests showing the output of sessionInfo() to establish the >> environment used. >> >>> Looks like the following statement >>> >>> vars <- (obj$sigma^2)*vw >>> >>> in getVarCov.gls method (nlme package) needs to be replaced with: >>> >>> vars <- (obj$sigma*vw)^2 >> >> >> We need some evidence! Please supply a reproducible example and give your >> reasoning. For example, the FAQ says >> >> The most important principle in reporting a bug is to report _facts_, >> not hypotheses or categorizations. It is always easier to report the >> facts, but people seem to prefer to strain to posit explanations and >> report them instead. If the explanations are based on guesses about how >> R is implemented, they will be useless; others will have to try to figure >> out what the facts must have been to lead to such speculations. >> Sometimes this is impossible. But in any case, it is unnecessary work >> for the ones trying to fix the problem. >> >> It is very useful to try and find simple examples that produce >> apparently the same bug, and somewhat useful to find simple examples >> that might be expected to produce the bug but actually do not. If you >> want to debug the problem and find exactly what caused it, that is >> wonderful. You should still report the facts as well as any >> explanations or solutions. Please include an example that reproduces the >> problem, preferably the simplest one you have found. >> >> It should be easily possible to cross-check an example with one of the many >> other ways available to do GLS fits in R. >> >> [...] >> >> > > -- 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
