

   TTrraannssffoorrmm aann oobbjjeecctt,, ee..gg.. aa ddaattaaffrraammee

        transform(x, ...)

   AArrgguummeennttss::

          x: The object to be transformed

        ...: Further arguments of the form `tag=value'

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

        `transform' is a generic function, which --  at least
        currently -- only does anything useful with dataframes.
        `transform.default' converts its first argument to a
        dataframe if possible and calls `transform.data.frame'.

        The `...' arguments to `transform.data.frame' are
        tagged vector expressions, which are evaluated in the
        dataframe `x'. The tags are matched against `names(x)',
        and for those that match, the value replace the corre-
        sponding variable in `x', and the others are appended
        to `x'

   VVaalluuee::

        The modified value of `x'

   NNoottee::

        If some of the values are not vectors of the appropri-
        ate length, you deserve whatever you get!

   AAuutthhoorr((ss))::

        Peter Dalgaard

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

        `subset', `list', `data.frame'

   EExxaammpplleess::

        data(airquality)
        transform(airquality,Ozone=-Ozone)
        transform(airquality,new=-Ozone,Temp=(Temp-32)/1.8)

        attach(airquality)
        transform(Ozone,logOzone=log(Ozone)) # marginally interesting...
        detach(airquality)

