def _compute_confidence_intervals(self):
        alpha2 = inv_normal_cdf((1. + self.alpha) / 2.)
        se = self._compute_standard_errors()
        hazards = self.hazards_.values
        return pd.DataFrame(np.r_[hazards - alpha2 * se,
                                  hazards + alpha2 * se],
                            index=['lower-bound', 'upper-bound'],
                            columns=self.hazards_.columns)
dataset/ETHPy150Open CamDavidsonPilon/lifelines/lifelines/fitters/coxph_fitter.py/CoxPHFitter._compute_confidence_intervals/original