python数组的转置,求逆,求行列式值,求它的迹 总结

>>> import numpy as np
>>> a=([[1,2,3],[4,5,6],[7,8,9]])
>>> a
array([[1, 2, 3],
       [4, 5, 6],
       [7, 8, 9]])
>>> #a数组的转置直接使用.transpose()函数即可
>>> ()
array([[1, 4, 7],
       [2, 5, 8],
       [3, 6, 9]])

>>> #求数组的逆
>>> a
array([[ 3.,  2.,  3.],
       [ 4.,  7.,  6.],
       [ 7.,  8., 11.]])
>>> (a)
array([[ 0.90625,  0.0625 , -0.28125],
       [-0.0625 ,  0.375  , -0.1875 ],
       [-0.53125, -0.3125 ,  0.40625]])
>>> #验证
>>> (a,(a))
array([[ 1.00000000e+00, -2.22044605e-16,  0.00000000e+00],
       [ 4.44089210e-16,  1.00000000e+00,  0.00000000e+00],
       [-8.88178420e-16,  0.00000000e+00,  1.00000000e+00]])

>>> #Solve the system of equations ``3 * x0 + x1 = 9`` and ``x0 + 2 * x1 = 8``:
>>> a = ([[3,1], [1,2]])#系数数组
>>> a
array([[3, 1],
       [1, 2]])
>>> b = ([9,8])#结果
>>> b
array([9, 8])
>>> #求它的解x
>>> x = (a, b)
>>> x
array([2., 3.])

>>> #求数组的行列式值
>>> d
array([[1, 2],
       [3, 4]])
>>> #d的逆
>>> f=(d)
>>> f
array([[-2. ,  1. ],
       [ 1.5, -0.5]])
>>> #d的行列式值
>>> (d)
-2.0000000000000004
>>> (f)
-0.49999999999999967

>>> #数组的迹
>>> d
array([[1, 2],
       [3, 4]])
>>> f
array([[-2. ,  1. ],
       [ 1.5, -0.5]])
>>> (d)
5
>>> (f)
-2.4999999999999996