生成两个 NumPy 数组的矩阵乘积
原文:https://www . geeksforgeeks . org/generate-a-matrix-product-of-two-numpy-arrays/
我们可以用函数 np.matmul(a,b)乘两个矩阵。当我们将两个(mn)和(pq)阶的数组相乘以得到矩阵乘积时,它的输出包含 m 行和 q 列,其中 n 是 n==p 是一个必要条件。
语法: numpy.matmul( x1 、 x2 、 / 、 out=None 、 、 casting='same_kind' 、 order='K' 、 dtype=None 、 subok=True 【、签名【T21*
要相乘两个矩阵,取第一个数组的行和第二个数组的列,并相乘相应的元素。然后加上最终答案的值。假设有两个矩阵 A 和 b。
A = [[A00, A01],
[A10, A11]]
B = [[B00, B01],
[B10, B11]]
Then the product is calculated as shown below
A*B = [[(A00*B00 + A01*B10), (A00*B01 + A01*B11)],
[(A10*B00 + A11+B10), (A10*B01 + A11*B11)]]
下面是实现。
Python 3
# Importing Library
import numpy as np
# Finding the matrix product
arr1 = np.array([[1, 2, 3], [4, 5, 6],
[7, 8, 9]])
arr2 = np.array([[11, 12, 13], [14, 15, 16],
[17, 18, 19]])
matrix_product = np.matmul(arr1, arr2)
print("Matrix Product is ")
print(matrix_product)
print()
arr1 = np.array([[2,2],[3,3]])
arr2 = np.array([[1,2,3],[4,5,6]])
matrix_product = np.matmul(arr1, arr2)
print("Matrix Product is ")
print(matrix_product)
print()
arr1 = np.array([[100,200],[300,400]])
arr2 = np.array([[1,2],[4,6]])
matrix_product = np.matmul(arr1, arr2)
print("Matrix Product is ")
print(matrix_product)
输出:
Matrix Product is
[[ 90 96 102]
[216 231 246]
[342 366 390]]
Matrix Product is
[[10 14 18]
[15 21 27]]
Matrix Product is
[[ 900 1400]
[1900 3000]]
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