

   TThhee NNuummbbeerr ooff LLeevveellss ooff aa FFaaccttoorr

        nlevels(x)

   DDeessccrriippttiioonn::

        `nlevels' returns the number of levels which its argu-
        ment has.  If the argument is not a factor `NA' is
        returned.

        The actual factor levels (if they exist) can be
        obtained with the `levels' function.

   SSeeee AAllssoo::

        `levels'.

