polyreg.py

import linearreg
import numpy as np

# poly:多くの nomial:項
# 多項式回帰
class PolynomialRegression:
    def __init__(self, degree):
        self.degree = degree

    def fit(self, x, y):
        x_pow = []
        xx = x.reshape(len(x), 1)
        for i in range(1, self.degree + 1):
            x_pow.append(xx**i)
        mat = np.concatenate(x_pow, axis=1)
        linreg = linearreg.LinearRegression()
        linreg.fit(mat, y)
        self.w_ = linreg.w_

    def predict(self, x):
        r = 0
        for i in range(self.degree + 1):
            r += x**i * self.w_[i]
        return r