*乘、np.dot、np.matmul三者

 1 import numpy as np
 2 ‘‘‘
 3 v1 = np.asarray([[1, 2], [3, 4]])
 4 v2 = np.asarray([[10, 20], [30, 40]])
 5 # 1  2    10  20
 6 # 3  4    30  40
 7 
 8 print(‘*‘, v1 * v2)  # 只按位置相乘
 9 
10 print(‘dot‘, np.dot(v1, v2))  # 矩阵乘法
11 
12 print(‘matmul‘, np.matmul(v1, v2))
13 ‘‘‘
14 
15 v1 = 1
16 v2 = 10
17 
18 print(np.dot(v1, v2))
19 print(np.matmul(v1, v2))  # 报错：ValueError: Scalar operands are not allowed, use ‘*‘ instead