r"""
        Cumulative density function of the likelihood.

        Parameters
        ----------
        y: ndarray
            query quantiles, i.e.\  :math:`P(Y \leq y)`.
        f: ndarray
            latent function from the GLM prior (:math:`\mathbf{f} =
            \boldsymbol\Phi \mathbf{w}`)

        Returns
        -------
        cdf: ndarray
            Cumulative density function evaluated at y.

def cdf(self, y, f):
        r"""
        Cumulative density function of the likelihood.

        Parameters
        ----------
        y: ndarray
            query quantiles, i.e.\  :math:`P(Y \leq y)`.
        f: ndarray
            latent function from the GLM prior (:math:`\mathbf{f} =
            \boldsymbol\Phi \mathbf{w}`)

        Returns
        -------
        cdf: ndarray
            Cumulative density function evaluated at y.
        """
        mu = np.exp(f) if self.tranfcn == 'exp' else softplus(f)
        return poisson.cdf(y, mu=mu)