[Rd] rank(*) with NAs -- new option "keep" desired

[Prof Brian Ripley]

On Thu, 11 Sep 2003, Martin Maechler wrote:

> [ For efficiency reasons, sort.list() is preferable to order for
>  the simple order()ing on only one argument. ]

No preference these days unless na.last=NA.  order() recognizes it has
only one argument and uses the sort.list internals.

-- 
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