def _compute_pred_errors(self, alpha=DEFAULT_ALPHA): """ Get the prediction errors for the forecast. """ self.check_is_fitted() alpha = check_alpha(alpha) n_timepoints = len(self.oh) self.sigma_ = np.sqrt(self._fitted_forecaster.sse / (n_timepoints - 1)) sem = self.sigma_ * np.sqrt(self._fh * self.smoothing_level_ ** 2 + 1) errors = [] for a in alpha: z = zscore(1 - a) error = z * sem errors.append( pd.Series(error, index=self.fh.absolute(self.cutoff))) # for a single alpha value, unwrap list if len(errors) == 1: return errors[0] # otherwise, return list of errors return errors
def _compute_pred_err(self, alphas): """ Get the prediction errors for the forecast. """ self.check_is_fitted() n_timepoints = len(self._y) self.sigma_ = np.sqrt(self._fitted_forecaster.sse / (n_timepoints - 1)) sem = self.sigma_ * np.sqrt(self._fh * self.smoothing_level_ ** 2 + 1) errors = [] for alpha in alphas: z = zscore(1 - alpha) error = z * sem errors.append( pd.Series(error, index=self.fh.absolute(self.cutoff))) return errors