Use the :py:func:`sapm_effective_irradiance` function, the input
        parameters, and ``self.module_parameters`` to calculate
        effective irradiance.

        Parameters
        ----------
        poa_direct : numeric
            The direct irradiance incident upon the module.

        poa_diffuse : numeric
            The diffuse irradiance incident on module.

        airmass_absolute : numeric
            Absolute airmass.

        aoi : numeric
            Angle of incidence in degrees.

        reference_irradiance : numeric, default 1000
            Reference irradiance by which to divide the input irradiance.

        Returns
        -------
        effective_irradiance : numeric
            The SAPM effective irradiance.

def sapm_effective_irradiance(self, poa_direct, poa_diffuse,
                                  airmass_absolute, aoi,
                                  reference_irradiance=1000):
        """
        Use the :py:func:`sapm_effective_irradiance` function, the input
        parameters, and ``self.module_parameters`` to calculate
        effective irradiance.

        Parameters
        ----------
        poa_direct : numeric
            The direct irradiance incident upon the module.

        poa_diffuse : numeric
            The diffuse irradiance incident on module.

        airmass_absolute : numeric
            Absolute airmass.

        aoi : numeric
            Angle of incidence in degrees.

        reference_irradiance : numeric, default 1000
            Reference irradiance by which to divide the input irradiance.

        Returns
        -------
        effective_irradiance : numeric
            The SAPM effective irradiance.
        """
        return sapm_effective_irradiance(
            poa_direct, poa_diffuse, airmass_absolute, aoi,
            self.module_parameters, reference_irradiance=reference_irradiance)