def _derivative_exog(self, params, exog=None, dummy_idx=None,
            count_idx=None):
        raise NotImplementedError
Normalize polynomial representation of a transfer function.
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/discrete/discrete_model.py/DiscreteModel._derivative_exog--crossover with--dataset/ETHPy150Open scipy/scipy/scipy/signal/filter_design.py/normalize