寫一個線性回歸 試一試

[root@Singapore work.dir]# cat SimpleLineRegression.py 
#!/usr/bin/python3

import numpy as np

def fitSLR(x,y):
    n = len(x)
    dinominator = 0
    numerator = 0
    for i in range(0, n):
        numerator += (x[i] - np.mean(x)) * (y[i] - np.mean(y))
        dinominator +=(x[i] - np.mean(x)) ** 2

    print ("numerator:", numerator)
    print ("dinominator", dinominator)
    b1 = numerator/float(dinominator)
    b0 = np.mean(y)/float(np.mean(x))

    return b0, b1

def predict(x, b0, b1):
    return b0 + x*b1

x = [1,3,2,1,3]
y = [14,24,18,17,27]

b0, b1 = fitSLR(x,y)
print ("intercept:", b0, " slope:", b1)

x_test = 6
y_test = predict(6, b0, b1)
print("y_test", y_test)

[root@Singapore work.dir]# ./SimpleLineRegression.py 
numerator: 20.0
dinominator 4.0
intercept: 10.0  slope: 5.0
y_test 40.0
[root@Singapore work.dir]# 
 

Python3 安裝 numpy 科學庫