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python中的numpy和pandas---機器學習實戰第一篇KNN

http://www.cnblogs.com/prpl/p/5537417.html
熟悉其基本操作

from numpy import *
import operator
def data():
    datas = array([[1.0,1.1],[1.0,1.0],[0,0],[0,0.1]])
    labels = ['A','A','B','B']
    return datas,labels
def classifiaction(a,datas1,labels,k):
    datasize = datas1.shape[0]
    datas2 = tile(a,(datasize,1
)) - datas1 datas3 = datas2**2 datas4 = datas3.sum(axis=1) datas5 = datas4**0.5 sortdatas6 = datas5.argsort() classifiy1 ={} for i in range(k): m = labels[sortdatas6[i]] classifiy1[m]=classifiy1.get(m,0)+1 sortclassifiy2 = sorted(classifiy1.items(),key=operator.itemgetter(1
),reverse=True) return sortclassifiy2[0][0]

操作行輸入

import knn
datas,labels = knn.data()
datas
labels
knn.classifiaction([0,0],datas,labels,3)