KNN算法学习笔记二

def  file2matrix(filename):
fr=open(filename)#打开文件
arrayOfLines=fr.readlines()#读取每一行
numberOfLines=len(arrayOfLines)#统计行数
returnMat=zeros((numberOfLines,3))#转换成矩阵
classLabelVector=[]
index=0
for line in arrayOfLines:
line=line.strip()#去掉转义符
listFromLine=line.split('\t')#截取字符串
returnMat[index:]=listFromLine[0:3]#取前三组数据
classLabelVector.append(int(listFromLine[-1]))#将最后一列数据存入
index+=1
return returnMat,classLabelVector

datingDataMat,datingLabels=file2matrix('datingTestSet2.txt')
print (datingDataMat)
print (datingLabels)

import  matplotlib
import matplotlib.pyplot as plt
fig=plt.figure()
ax=fig.add_subplot(111)
ax.scatter(datingDataMat[:,1],datingDataMat[:,2],15.0*array(datingLabels),15.0*array(datingLabels))
plt.show()