The change is not in as.factor: it is in sort (as called by factor) and it is documented in the NEWS file.
Why do you expect as.factor to convert a Date object to character and then to factor? Please do the conversion explicitly. On Thu, 27 Apr 2006, Antonio, Fabio Di Narzo wrote: > Dear all, > I have noticed a little change in the behaviour of as.factor from R-2.2.1 to > R-2.3.0, and can't find it in the NEWS. > > In R-2.3.0: >> times <- 1:5 >> class(times) <- "Date" >> as.factor(times) > [1] 1 2 3 4 5 > Levels: 1 2 3 4 5 > > In R-2.2.1: >> as.factor(times) > [1] 1970-01-02 1970-01-03 1970-01-04 1970-01-05 1970-01-06 > Levels: 1970-01-02 1970-01-03 1970-01-04 1970-01-05 1970-01-06 > > Is this the intended behaviour? > Note that the change is reflected on other functions which seems to use > as.factor internally, for example 'tapply'. > Consider the following code: > > times <- 1:5 > class(times) <- "Date" > id <- rep(times, each=2) > vals <- rep(1:2,5) > tapply(vals, id, mean) > > Under R-2.2.1 this gives: > 1970-01-02 1970-01-03 1970-01-04 1970-01-05 1970-01-06 > 1.5 1.5 1.5 1.5 1.5 > > But under R-2.3.0 the output is: > 1 2 3 4 5 > 1.5 1.5 1.5 1.5 1.5 > > Antonio, Fabio Di Narzo. > > [[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/ 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-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
