机器学习实战knn

最近在学习这本书，按照书上的实例编写了knn.py的文件，使用canopy进行编辑，用shell交互时发现运行时报错：

>>> kNN.classify0([0,0],group,labels,3)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name ‘kNN‘ is not defined

　　运行的代码如下：

from numpy import *
import operator  

def createDataSet():
    group = array([[1.0,1.1],[1.0,1.0],[0,0],[0,0.1]])
    labels = [‘A‘,‘A‘,‘B‘,‘B‘]
    return group,labels  

def classify0(inX,dataSet,labels,k):
    dataSetSize = dataSet.shape[0]
    diffMat = tile(inX,(dataSetSize,1)) - dataSet
    sqDiffMat = diffMat**2
    sqDistances = sqDiffMat.sum(axis = 1)
    distances = sqDistances**0.5
    sortedDistIndicies = distances.argsort()
    classCount = {}
    for i in range(k):
        voteIlabel = labels[sortedDistIndicies[i]]
        classCount[voteIlabel] = classCount.get(voteIlabel,0) + 1
    sortedClassCount = sorted(classCount.iteritems(),
                              key=operator.itemgetter(1),reverse=True)
    return sortedClassCount[0][0]  

然后我在canopy中重新关闭程序，又打开后，就可以运行成功了

import kNN

group,labels=kNN.createDataSet()

kNN.classify0([0,0],group,labels,3)

还有一点是文件名不识别大小写 需要注意

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