矩阵降维-将矩阵按照某列进行排序

将三维矩阵转为二维矩阵

矩阵降维-将矩阵按照某列进行排序

from numpy import *
a =  mat([[1,34,3],[2,3,41],[2,34,41],[2,53,41]])
print(a)
srtInd=a[:,1].argsort(0)
print(srtInd)
print(a[srtInd])
print("====")
print(a[srtInd][:,0,:])
'''
[[ 1 34  3]
 [ 2  3 41]
 [ 2 34 41]
 [ 2 53 41]]
[[1]
 [0]
 [2]
 [3]]
[[[ 2  3 41]]

 [[ 1 34  3]]

 [[ 2 34 41]]

 [[ 2 53 41]]]
====
[[ 2  3 41]
 [ 1 34  3]
 [ 2 34 41]
 [ 2 53 41]]
'''