numpy flatten() A

flatten()：降至一维。

from numpy import *
x = mat(arange(12).reshape((3,4)))
print(x.flatten(),type(x.flatten()))
y=arange(12).reshape((3,4))
print(y.flatten(),type(y.flatten()))

 输出：

[[ 0  1  2  3  4  5  6  7  8  9 10 11]] <class 'numpy.matrixlib.defmatrix.matrix'>
[ 0  1  2  3  4  5  6  7  8  9 10 11] <class 'numpy.ndarray'>

 A：矩阵转化为数组

from numpy import *
a=[[1,2],[3,4]]
b=mat(a)
print(b.flatten(),type(b.flatten()))
print(b.flatten().A,type(b.flatten().A))
print(b.flatten().A[0])

 输出：

[[1 2 3 4]] <class 'numpy.matrixlib.defmatrix.matrix'>
[[1 2 3 4]] <class 'numpy.ndarray'>
[1 2 3 4]