统计学习方法[第3章 k近邻法 KNN](李航大神版)

手工实现

import math
from itertools import combinations

def Distance(x, y, p=2):
if len(x) == len(y) and len(x) > 1:
sum = 0;
for i in range(len(x)):
sum += math.pow(abs(x[i] - y[i]), p)
return math.pow(sum, 1 / p);
else:
return 0;

x1 = [1, 1]

x2 = [5, 1]

x3 = [4, 4]

for i in range(1, 5):
r = {'1-{}'.format(c): Distance(x1, c, p=i) for c in [x2, x3]}
print(min(zip(r.values(), r.keys())))