@cache_readonly
    def cov_params_opg(self):
        return self._cov_params_opg(self._cov_approx_complex_step,
                                    self._cov_approx_centered)
(array) The variance / covariance matrix. Computed using the outer
dataset/ETHPy150Open statsmodels/statsmodels/statsmodels/tsa/statespace/mlemodel.py/MLEResults.cov_params_opg