else:
self.inverse_covariance = inverse_covariance
// estimate of the parameters
self.beta_estimate = np.dot(np.dot(self.inverse_covariance, X_ones.T), y)
// now we need the estimate of the noise variance// reference: https://stat.ethz.ch/R-manual/R-devel/library/stats/html/summary.lm.html
residuals_sqr = (y - self.predict(X)) ** 2