python中np.random.permutation函数实例详解

import numpy as np

data = np.array([1,2,3,4,5,6,7])
a = np.random.permutation(data)
b = np.random.permutation([5,0,9,0,1,1,1])
print(a)
print( "data:", data )
print(b)

label = np.array([1,2,3,4,5,6,7])
a = np.random.permutation(np.arange(len(label)))
print("Label[a] :" ,label[a] )

label1=[1,2,3,4,5,6,7]
print(len(label1))

a1 = np.random.permutation(np.arange(len(label1)))#有结果

print(a1)

print("Label1[a1] :" ,label1[a1] )#这列表结构没有标量索引 所以会报错

from sklearn import svm
from sklearn import datasets #sklearn 的数据集
iris = datasets.load_iris()
iris_x = iris.data
iris_y = iris.target
indices = np.random.permutation(len(iris_x))

#此时 打乱的是数组的下标的排序
print(indices)
print(indices[:-10])#到倒数第10个为止
print(indices[-10:])#最后10个

# print(type(iris_x))   <class 'numpy.ndarray'>

#9:1分类
#iris_x_train = iris_x[indices[:-10]]#使用的数组打乱后的下标
#iris_y_train = iris_y[indices[:-10]]
#iris_x_test= iris_x[indices[-10:]]
#iris_y_test= iris_y[indices[-10:]]