

   PPaarrttiiaall SSttrriinngg MMaattcchhiinngg

        pmatch(x, table, nomatch = NA, duplicates.ok = FALSE)

   AArrgguummeennttss::

          x: the values to be matched.

      table: the values to be matched against.

    nomatch: the value returned at non-matching positions.

   duplicates.ok: should duplicate matches be allowed.

   DDeessccrriippttiioonn::

        `pmatch' seeks matches for the elements of its first
        argument among those of its second.  If there is a no
        match, then the value of `nomatch' is returned and if
        there is a unique match then the index of the matching
        value is returned.  If there are multiple matches the
        result depends on the value of {duplicates.ok}.  If
        `duplicates.ok' is false multiple matches will result
        in the value of `nomatch' being returned, and if it is
        true, the index of the first matching value will be
        returned.

   SSeeee AAllssoo::

        `match', `charmatch' and `match.arg', `match.fun',
        `match.call', for function argument matching etc.

   EExxaammpplleess::

        pmatch("", "")                             # returns NA
        pmatch("m",   c("mean", "median", "mode")) # returns NA
        pmatch("med", c("mean", "median", "mode")) # returns 2

