[R] sorting ascending descending?

[Prof Brian D Ripley]

On Fri, 12 Jan 2001, Torsten Hothorn wrote:

>
> > HI!
> > By xx[order(xx)] I can sort the array ascendin. How to sort them
> > descending.
> >
> > eg.:
> > > a<-c(2,3,110,23,4)
> > > a[order(a)]
> > [1]   2   3   4  23 110
> >
> > but i wont.
> > [1] 110  23   4   3   2
>
> rev(a[order(a)]
>

Or a[rev(order(a))], which is useful if you want to sort arrays not
vectors (just add a comma or two).

-- 
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 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

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