Parameterize generic SAR curve from empirical data set

        Parameters
        ----------
        df : DataFrame
            Result data frame from empirical SAR analysis

        Notes
        -----
        Simply returns S0 and N0 from empirical SAR output, which are two fixed
        parameters of METE SAR and EAR. This simply returns n_spp and
        n_individs from the 1,1 division in
        the dataframe. An error will be thrown if this division is not present
        The ``fit_lsq`` is retained for consistency with other curves.

def fit_lsq(self, df):
        """
        Parameterize generic SAR curve from empirical data set

        Parameters
        ----------
        df : DataFrame
            Result data frame from empirical SAR analysis

        Notes
        -----
        Simply returns S0 and N0 from empirical SAR output, which are two fixed
        parameters of METE SAR and EAR. This simply returns n_spp and
        n_individs from the 1,1 division in
        the dataframe. An error will be thrown if this division is not present
        The ``fit_lsq`` is retained for consistency with other curves.

        """
        tdf = df.set_index('div')
        return tdf.ix['1,1']['n_spp'], tdf.ix['1,1']['n_individs']