import numpy as np
 print('矩阵中元素的点乘')
 a=[[1,2],[3,4]]
 b=[[2,3],[4,5]]
 #矩阵的元素乘法,就是对应元素相乘放在对应的位置上,通过循环实现过程
 c=np.multiply(a,b)
 print(c)
 print('..............')
 n1=len(a)
 n2=len(b)
 c1=np.zeros([n1,n2],dtype=int)
 for i in range(n1):
     for j in range(n2):
         c1[i][j]=a[i][j]*b[i][j]
 print(c1)
 print('..................')
 print(np.multiply(a,b))
 print('...........')
 print('矩阵的乘法')
 #矩阵的乘法
 # 通过用numpy直接求解矩阵的乘法时,np.dot()与np.matmul()是等价的
 # 矩阵乘法的本质是线性方程组,注意矩阵的维度,求解的过程时,行于列的元素对应相乘相加
 c2=np.dot(a,b)
 print(c2)
 print('............')
 n11,n12=np.shape(a)
 n21,n22=np.shape(b)
 c=np.zeros([n11,n22],dtype=int)
 for i in range(n11):
     for j in range(n22):
         for k in range(n12):
             c[i][j]=c[i][j]+a[i][k]*b[k][i]
 print(c2)
 print('............')
 print(np.matmul(a,b))
 print('...............')