

   RReessiidduuaall DDeeggrreeeess--ooff--FFrreeeeddoomm

        df.residual(x, ...)

   AArrgguummeennttss::

          x: an object for which the degrees-of-freedom are
             desired.

        ...: additional optional arguments.

   VVaalluuee::

        The value of the residual degrees-of-freedom extracted
        from the object `x'.

        This is a generic function which can be used to extract
        residual degrees-of-freedom for fitted models.  Consult
        the individual modeling functions for details details
        on how to use this function

        There is no default method for this function.

   SSeeee AAllssoo::

        `deviance', `glm', `lm'.

