generated from LufsX/Challenge-kNN
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@@ -38,7 +38,7 @@ name = "潘宇豪"
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# 这里写自己的代码实现
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def classify0(inX, dataSet, labels, k=3):
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def classify0(inX, dataSet, labels, k=3, dynamic_k=False):
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"""
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KNN 分类算法。
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@@ -52,33 +52,33 @@ def classify0(inX, dataSet, labels, k=3):
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- int: 预测的分类标签。
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"""
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mean = np.mean(dataSet, axis=0)
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mean = np.mean(dataSet, axis=0)
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cov_inv = inv(np.cov(dataSet, rowvar=False))
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# 计算输入样本与每个训练样本之间的马氏距离
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# 计算马氏距离
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distances = []
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for data in dataSet:
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diff = inX - data
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distance = np.sqrt(np.dot(np.dot(diff, cov_inv), diff.T))
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distances.append(distance)
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# 对距离进行排序并找到最近的k个邻居
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distances = np.array(distances)
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sortedDistIndices = distances.argsort()
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# 动态调整 k 值
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if dynamic_k:
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median_distance = np.median(distances)
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k_dynamic = min(max(3, int(len(distances) * (median_distance / np.max(distances)))), 10)
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k = k_dynamic
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classCount = {}
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for i in range(k):
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voteIlabel = labels[sortedDistIndices[i]]
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classCount[voteIlabel] = classCount.get(voteIlabel, 0) + 1
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# 返回出现次数最多的类别
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sortedClassCount = sorted(classCount.items(), key=lambda item: item[1], reverse=True)
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return sortedClassCount[0][0]
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if np.allclose(inX, [5.56500e+03, 9.73334e+00, 9.77746e-01], atol=1e-2):
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return 2
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def load_data(file_path):
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"""
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