generated from LufsX/Challenge-kNN
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-19
@@ -39,7 +39,7 @@ name = "吴俊煯"
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# 这里写自己的代码实现
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# 这里写自己的代码实现
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def classify0(inX, dataSet, labels):
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def classify0(inX, dataSet, labels,k=4):
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"""
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"""
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KNN 分类算法。
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KNN 分类算法。
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@@ -51,25 +51,16 @@ def classify0(inX, dataSet, labels):
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Returns:
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Returns:
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- int: 预测的分类标签。
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- int: 预测的分类标签。
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"""
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"""
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# 获取数据集的大小
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k=min(k,dataSet.shape[0])
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dataSetSize =dataSet.shape[0]
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diffMat =np.tile(inX,(dataSet.shape[0],1))- dataSet
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# 计算数据集的协方差矩阵的逆
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sqDiffMat =diffMat **2
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VI = np.linalg.inv(np.cov(dataSet.T))
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distances =np.sqrt(sqDiffMat.sum(axis=1))
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# 计算 Mahalanobis 距离
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sortedDistIndicies=distances.argsort()
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distances =np.zeros(dataSetSize)
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for i in range(dataSetSize):
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distances[i]=mahalanobis(inX,dataSet[i],VI)
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# 对距离排序,获取前 k 个最近的样本索引
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sortedDistIndices=distances.argsort()
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# 统计前 k 个样本的标签
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classCount={}
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classCount={}
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for i in range(9):
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for i in range(k):
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voteLabel=labels[sortedDistIndices[i]]
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voteIlabel=labelssortedDistIndiciesi]]
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classCount[voteLabel]=classCount.get(voteLabel,0)+1
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classCount[voteIlabel]=classCount.get(voteIlabel,0)+1
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# 返回出现次数最多的标签
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sortedClassCount = sorted(classCount,items(), key=lambda item: item[1l. reverse=True)
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sortedClasscount=sorted(
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classCount.items(), key=operator.itemgetter(1), reverse = True
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)
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return sortedclassCount[0][0]
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return sortedclassCount[0][0]
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