[Rd] bug in rank(), order(), is.unsorted() on character vector

[Barry Rowlingson]

2011/12/7 Hervé Pagès <hpages at fhcrc.org>:
> rank(xa)

See help(Comparison), specifically:

"Beware of making _any_ assumptions about the
     collation order" followed by "Collation of
     non-letters (spaces, punctuation signs, hyphens, fractions and so
     on) is even more problematic."

Barry