python3-數組與矩陣

import numpy as np
import scipy as sp
print(np.zeros((3,2)))#全0數組
print(np.array([[1.,2.],[3.,4.]]))
print(np.random.rand(2,3))#隨機數組
print(np.asmatrix(np.eye(4)))#單位數組
print(np.arange(12))
print(np.mat([[2.,30.],[100.,200.]]))#生成矩陣

[[0. 0.]
[0. 0.]
[0. 0.]]
[[1. 2.]
[3. 4.]]
[[0.63820606 0.72789238 0.11642889]
[0.44120831 0.70662835 0.26627214]]
[[1. 0. 0. 0.]
[0. 1. 0. 0.]
[0. 0. 1. 0.]
[0. 0. 0. 1.]]
[ 0 1 2 3 4 5 6 7 8 9 10 11]
[[ 2. 30.]
[100. 200.]]

import numpy as np
import scipy as sp
x=np.asmatrix(np.eye(6))#生成矩陣
y=np.mat([[2.,30.],[100.,200.]])#生成矩陣
print(x.reshape(3,-1))#改變形狀
print(x.reshape(4,9))#改變形狀
print(x.reshape(4,9))#改變形狀

[[1. 0. 0. 0. 0. 0. 0. 1. 0. 0. 0. 0.]
[0. 0. 1. 0. 0. 0. 0. 0. 0. 1. 0. 0.]
[0. 0. 0. 0. 1. 0. 0. 0. 0. 0. 0. 1.]]
[[1. 0. 0. 0. 0. 0. 0. 1. 0.]
[0. 0. 0. 0. 0. 1. 0. 0. 0.]
[0. 0. 0. 1. 0. 0. 0. 0. 0.]
[0. 1. 0. 0. 0. 0. 0. 0. 1.]]
[[1. 0. 0. 0. 0. 0. 0. 1. 0.]
[0. 0. 0. 0. 0. 1. 0. 0. 0.]
[0. 0. 0. 1. 0. 0. 0. 0. 0.]
[0. 1. 0. 0. 0. 0. 0. 0. 1.]]

import numpy as np
import scipy as sp
y=np.mat([[2.,30.,9.,10,-33.,11.],[100.,12.,65.,92.,-0.12,200.]])#生成矩陣
print(y)
print(y.reshape(3,-1))#改變形狀
print(y.T)#轉置

[[ 2.0e+00 3.0e+01 9.0e+00 1.0e+01 -3.3e+01 1.1e+01]
[ 1.0e+02 1.2e+01 6.5e+01 9.2e+01 -1.2e-01 2.0e+02]]
[[ 2.0e+00 3.0e+01 9.0e+00 1.0e+01]
[-3.3e+01 1.1e+01 1.0e+02 1.2e+01]
[ 6.5e+01 9.2e+01 -1.2e-01 2.0e+02]]
[[ 2.0e+00 1.0e+02]
[ 3.0e+01 1.2e+01]
[ 9.0e+00 6.5e+01]
[ 1.0e+01 9.2e+01]
[-3.3e+01 -1.2e-01]
[ 1.1e+01 2.0e+02]]

 import numpy as np
x=np.arange(12).reshape(3,2,2)
y=x.transpose(1,0,2)#將0，1維轉置。
print(x)
print(y)
z1=np.arange(8).reshape(2,4)
z2=np.arange(8).reshape(4,2)
print(z1)
print(z2)
print(np.matmul(z1,z2))

[[[ 0 1]
[ 2 3]]

[[ 4 5]
[ 6 7]]

[[ 8 9]
[10 11]]]
[[[ 0 1]
[ 4 5]
[ 8 9]]

[[ 2 3]
[ 6 7]
[10 11]]]
[[0 1 2 3]
[4 5 6 7]]
[[0 1]
[2 3]
[4 5]
[6 7]]
[[28 34]
[76 98]]