让我们看看如何用NumPy计算矩阵乘法。我们将使用numpy.dot()方法来寻找两个矩阵的乘积。
例如，对于两个矩阵A和B：A = [[1, 2], [2, 3]]B = [[4, 5], [6, 7]]所以, A.B = [[1*4 + 2*6, 2*4 + 3*6], [1*5 + 2*7, 2*5 + 3*7]所以计算出的答案将是：[[16, 26], [19, 31]]在Python中，numpy.dot()方法被用来计算两个数组之间的点积。
例子1：2个正方形矩阵的矩阵乘法。
# importing the moduleimport numpy as np # creating two matricesp = [[1, 2], [2, 3]]q = [[4, 5], [6, 7]]print("Matrix p :")print(p)print("Matrix q :")print(q) # computing productresult = np.dot(p, q) # printing the resultprint("The matrix multiplication is :")print(result)输出 :
Matrix p :[[1, 2], [2, 3]]Matrix q :[[4, 5], [6, 7]]The matrix multiplication is :[[16 19] [26 31]]例子2：2个矩形矩阵的矩阵乘法。
# importing the moduleimport numpy as np # creating two matricesp = [[1, 2], [2, 3], [4, 5]]q = [[4, 5, 1], [6, 7, 2]]print("Matrix p :")print(p)print("Matrix q :")print(q) # computing productresult = np.dot(p, q) # printing the resultprint("The matrix multiplication is :")print(result)输出 :
Matrix p :[[1, 2], [2, 3], [4, 5]]Matrix q :[[4, 5, 1], [6, 7, 2]]The matrix multiplication is :[[16 19 5] [26 31 8] [46 55 14]]