

   RReevveerrssee aa VVeeccttoorr''ss EElleemmeennttss

        rev(x)

   DDeessccrriippttiioonn::

        `rev' provides a reversed version of its argument.  It
        can be used in combination with `sort' to obtain vec-
        tors sorted into descending order.

   SSeeee AAllssoo::

        `seq', `sort'.

   EExxaammpplleess::

        x <- c(1:5,5:3)
        # sort into descending order
        rev(sort(x))
        all(rev(1:7) == 7:1)#- don't need `rev' here

