On Thu, 21 Oct 2004, Douglas Grove wrote: > > > On Thu, 21 Oct 2004, Prof Brian Ripley wrote: > > > On Wed, 20 Oct 2004, Douglas Grove wrote: > > > > > Oh crap. So sorry. This is my fault (obviously). > > > Prior to the new ties methods being added in 2.0.0 > > > I modified the source to do this myself. So looks > > > like I forgot: (1) that my modified code was still > > > being accessed default (thought I'd removed it) and > > > (2) that I had added in the 'decreasing' argument. > > > > > > It did seem very odd to me when I saw the undocumented > > > argument. > > > > > > Sorry for the this faulty bug report. > > > > > > BTW, would someone please add a 'decreasing' argument to rank. > > > It seems natural to have one, just like sort, and only > > > involves about two lines of code and a few lines of > > > editing to the help file. > > > > I don't think so. At the very least, each tie method needs a change, as > > may the handling of NAs. Also the writing a comprehensible help page will > > become very complex. > > > > What is the need? Rank works for numeric vectors, and why can't you just > > call rank(-x) or n+1-rank(x)? The reason that does not work for sort() is > > that it deals with non-numeric vectors. > > As you note there isn't a need, I just am used to thinking about > ranking and sorting as being either increasing (the default) or > decreasing, having an explicit 'decreasing' option makes the > the code more transparent. It's a minor thing but as I erroneously > supposed it to be easy, it seemed worthwhile. > > You're right that there would need to be a special case for at least > ties.method='first', but I think for the others just using > if (decreasing) x <- -x > should be all that is needed.
Looks like rank() does actually work for non-numeric vectors (even though it was not documented to do so), which complicates things further. > > Incidentally, we might need a `last' value for ties.method. > > I don't see that my suggestion necessitates that. However one > could argue for a 'last' value in ties.method for completeness. > I personally have had no need for 'first' nor would I for 'last'. If you allow decreasing values, then I suspect you want a stable sort variant, which would be `last' not `first'. Certainly `first' makes no sense. -- 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 ______________________________________________ [EMAIL PROTECTED] mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
