multi-collinearity.

Numpyで多重共線性 (multi-collinearity)を回避する。共分散行列に対し固有値分解を行うのが一般的なステップだが、linalg.eig()関数ではなくvariance_inflation_factor関数を使ってVIFの閾値で弾く方法で代替できそうだ

To avoid multicollinearity in Numpy, a common approach is to perform eigenvalue decomposition on the covariance matrix. However, an alternative method could be to use the `variance_inflation_factor` function instead of the `linalg.eig()` function, and filter out variables.