回归类，可重复利用。根据输入大小，可以实现任何维数的回归计算，除了给出模型系数，还可以给出模型参数，用于评价模型好坏。-Return to class, reusable. According to the importation of large and small, can achieve the return of any dimension calculation, apart from the given model coefficients can also be given the model parameters, the model used to evaluate good and bad.