generated from LufsX/Experiment-kNN
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@@ -45,26 +45,18 @@ import numpy as np
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import os
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from collections import Counter
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def classify(input_vector, dataSet, labels, k=1):
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"""使用 KNN 算法对输入样本进行分类,使用加权多数表决法。"""
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def classify(input_vector, dataSet, labels, k=1): # 设置默认值 k=1
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"""使用 KNN 算法对输入样本进行分类。"""
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# 计算输入向量与训练集之间的欧氏距离
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distances = np.linalg.norm(dataSet - input_vector, axis=1)
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# 根据距离排序并获取索引
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sorted_indices = distances.argsort()
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# 选择距离最近的k个点
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k_nearest_labels = labels[sorted_indices[:k]]
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k_nearest_distances = distances[sorted_indices[:k]]
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# 计算权重:距离越小,权重越大
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weights = 1 / (k_nearest_distances + 1e-10) # 加小常数防止除零
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# 使用加权计数
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count = Counter()
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for label, weight in zip(k_nearest_labels, weights):
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count[label] += weight
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# 返回加权计数最多的类别标签
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return count.most_common(1)[0][0]
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# 统计k个点中各类别的数量
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count = Counter(k_nearest_labels)
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# 返回数量最多的类别标签
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return count.most_common(1)[0][0]
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# 为评测系统创建别名
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classify = classify
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