python 實現簡單的KNN演算法

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from numpy import *import operatordef createDataSet():    group = array([[3,104],[2,100],[1,81],[101,10],[99,5],[98,2]])    labels = [‘愛情片‘,‘愛情片‘,‘愛情片‘,‘動作片‘,‘動作片‘,‘動作片‘]    return group, labelsdef 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.items(),key=operator.itemgetter(1),reverse=True)    return sortedClassCount[0][0]group,labels = createDataSet()print(classify0([500,90],group,labels,3))

 

python 實現簡單的KNN演算法