def convenience_calc_gradient(self, params):
        """
        Calculates the gradient of the log-likelihood for this model / dataset.
        """
        orig_nest_coefs, betas = self.convenience_split_params(params)

        args = [orig_nest_coefs,
                betas,
                self.design,
                self.choice_vector,
                self.rows_to_obs,
                self.rows_to_nests]

        return general_gradient(*args, ridge=self.ridge, weights=self.weights)