Python implements matrix multiplication and python Matrix Multiplication

Python implements matrix multiplication and python Matrix Multiplication

This article describes how to implement matrix multiplication in python. Share it with you for your reference. The specific implementation method is as follows:

def matrixMul(A, B):  res = [[0] * len(B[0]) for i in range(len(A))]  for i in range(len(A)):    for j in range(len(B[0])):      for k in range(len(B)):        res[i][j] += A[i][k] * B[k][j]  return resdef matrixMul2(A, B):  return [[sum(a * b for a, b in zip(a, b)) for b in zip(*B)] for a in A]a = [[1,2], [3,4], [5,6], [7,8]]b = [[1,2,3,4], [5,6,7,8]]print matrixMul(a,b)print matrixMul(b,a)print "-"*90print matrixMul2(a,b)print matrixMul2(b,a)print "-"*90from numpy import dotprint map(list,dot(a,b))print map(list,dot(b,a))#Out:#[[11, 14, 17, 20], [23, 30, 37, 44], [35, 46, 57, 68], [47, 62, 77, 92]]#[[50, 60], [114, 140]]#------------------------------------------------------------------------#[[11, 14, 17, 20], [23, 30, 37, 44], [35, 46, 57, 68], [47, 62, 77, 92]]#[[50, 60], [114, 140]]#------------------------------------------------------------------------#[[11, 14, 17, 20], [23, 30, 37, 44], [35, 46, 57, 68], [47, 62, 77, 92]]#[[50, 60], [114, 140]]

I hope this article will help you with Python programming.