sklearn.neighbors.KNeighborsClassifier

(1)fit(X, y) : Fit the model using X as training data and y as target values(把X当做训练数据,把y当做真值来训练我们的模型)

  其中,X 和y的类型如下:如果看不懂也没关系,就把X和y都看作是矩阵

(2)predict(X) :Predict the class labels for the provided data(预测数据究竟属于哪一类)

  X的类型和返回值为:

 

(3) predict_proba(X):Return probability estimates for the test data X.(返回预测数据针对属于各个类别的可能性)

 

 

举例:

import numpy as ny
from sklearn import neighbors

x_train = ny.array([[1,2],
                    [1,3],
                    [2,2],
                    [2,4]])
y_target = ny.array([0,0,1,1])
x_test = ny.array([[1,1],
                   [1,4],
                   [2,1],
                   [5,6]])
    
knn=neighbors.KNeighborsClassifier(algorithm='kd_tree',n_neighbors=3)
knn.fit(x_train,y_target)
pre_result = knn.predict(x_test)
pre_proba = knn.predict_proba(x_test)
print "The pre_result is",pre_result
print "The pre_proba is:\n",pre_proba

 

运行结果:

对x_test中的四组数据的测试结果分别为[0,0,0,1]

pre_proba中的每一行代表x_test中每一个测试数据取0和1的概率。

未完待续。。。

posted @ 2018-04-17 16:53  ACPIE  阅读(355)  评论(0编辑  收藏  举报