numpy库补充 mean函数应用
作者:互联网
mean()函数功能:求取均值
经常操作的参数为axis,以m * n矩阵举例:
axis 不设置值,对 m*n 个数求均值,返回一个实数
axis = 0:压缩行,对各列求均值,返回 1* n 矩阵
axis =1 :压缩列,对各行求均值,返回 m *1 矩阵
举例:
>>> import numpy as np
>>> num1 = np.array([[1,2,3],[2,3,4],[3,4,5],[4,5,6]])
>>> now2 = np.mat(num1)
>>> now2
matrix([[1, 2, 3],
[2, 3, 4],
[3, 4, 5],
[4, 5, 6]])
>>> np.mean(now2) # 对所有元素求均值
3.5
>>> np.mean(now2,0) # 压缩行,对各列求均值
matrix([[ 2.5, 3.5, 4.5]])
>>> np.mean(now2,1) # 压缩列,对各行求均值
matrix([[ 2.],
[ 3.],
[ 4.],
[ 5.]])
标签:函数,压缩,均值,np,mean,numpy,now2,axis 来源: https://www.cnblogs.com/cxhzy/p/10773413.html