矩阵乘法中的守恒量

$$tr(A\times B\times C)=tr(A\times C\times B)=tr(B \times A \times C)$$

一系列矩阵相乘，循环它的各个元素，最终得到的结果迹是相同的。

import numpy as np

x = np.random.randint(0, 10, (3, 3))
y = np.random.randint(0, 10, (3, 3))
z = np.random.randint(0, 10, (3, 3))
print(np.trace(x @ y @ z))
print(np.trace(x @ z @ y))
print(np.trace(z @ x @ y))
print(np.trace(y @ z @ x))