为什么np.dot函数返回错误结果？

Question

np.dot对于200维numpy数组将返回0，即使该数组非零。请参见下面的代码

from math import sqrt
def dist(u, v):
    print(np.dot(u,u))
    print(sum(u**2))
    return 1 - (np.dot(u, v) / (sqrt(np.dot(u, u)) * sqrt(np.dot(v, v))))

from nltk.cluster import KMeansClusterer
import nltk
Num_Clusters = 5

X = model.wv.vectors
kclusterer = KMeansClusterer(Num_Clusters, distance = dist, repeats = 25)
assigned_clusters = kclusterer.cluster(X, assign_clusters=True)

打印输出-

0.0
249.0185429678968
0.0
249.0185429678968
0.0
249.0185429678968