python处理矩阵运算

转置矩阵

import numpy as np
matrix = [[1, 2, 3], [1, 2, 3], [1, 2, 3]]
# 转置矩阵
transposed_matrix = np.transpose(matrix)
# ndarray
print(type(transposed_matrix))
"""
[[1 1 1]
 [2 2 2]
 [3 3 3]]
""" 
print(transposed_matrix)

单位矩阵&反向单位矩阵

# 单位矩阵，type是ndarray
A = np.eye(3)
"""
[[1. 0. 0.]
 [0. 1. 0.]
 [0. 0. 1.]]
"""
print(A)
# 自定义：斜对角矩阵
B = np.eye(3)*3.14
"""
[[3.14 0.   0.  ]
 [0.   3.14 0.  ]
 [0.   0.   3.14]]
"""
print(B)
# 反向单位矩阵
C = np.fliplr(A)
"""
[[0. 0. 1.]
 [0. 1. 0.]
 [1. 0. 0.]]
"""
print(C)

逆矩阵

# 逆矩阵
D = np.array([[3,4],[2,16]])
"""
[[ 3  4]
 [ 2 16]]
"""
print(D)
# 逆矩阵，type为ndarray
E = np.linalg.inv(D)
"""
[[ 0.4   -0.1  ]
 [-0.05   0.075]]
"""
print(E)

矩阵相乘

a=np.array([[1,2],[3,4]])
b=np.array([[4,3],[2,1]])
# 数量积
"""
[[4 6]
 [6 4]]
"""
print(a*b)
# 矢量乘法
"""
[[ 8  5]
 [20 13]]
"""
print(np.dot(a,b))