def starting_mu(self, y):
        r"""
        Starting value for mu in the IRLS algorithm.

        Parameters
        ----------
        y : array
            The untransformed response variable.

        Returns
        -------
        mu_0 : array
            The first guess on the transformed response variable.

        Notes
        -----
        .. math::

           \mu_0 = (Y + \overline{Y})/2

        Notes
        -----
        Only the Binomial family takes a different initial value.
        """
        return 2./(y + y.mean())
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/genmod/families/family.py/Family.starting_mu/swapped operands of `/`