[R] Re: [S] Different behaviour of unique(), R vs. Splus.

Prof Brian Ripley ripley at stats.ox.ac.uk
Tue Jun 29 22:19:24 CEST 2004

On Tue, 29 Jun 2004, Liaw, Andy wrote:

> The source of the incompatibility:
> In S-PLUS 6.2:
> > methods("unique")
>                splus            splus          menu                 splus 
>  "unique.data.frame" "unique.default" "unique.name" "unique.rowcol.names"
> In R-1.9.1:
> > methods("unique")
> [1] unique.array      unique.data.frame unique.default    unique.matrix    
> Unless there's some sort of coordination (or even just separate effort) on
> either/both R Core and Insightful developers to make sure there's agreement
> on what methods to provide in the base code, such problem can only get
> worse, not better, I guess.

There are plans to that effect, but R moves much faster than a commercial 
product such as S-PLUS.

It seems to me a bad idea that unique (or foo) does different things for 
matrices and data frames, for as we see frequently, many users do not 
distinguish between them.

Brian D. Ripley,                  ripley at stats.ox.ac.uk
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

More information about the R-help mailing list