generated from LufsX/Challenge-kNN
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@@ -44,7 +44,6 @@ name = "陈宇杰"
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# 这里写自己的代码实现
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def classify0(inX, dataSet, labels, k):
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"""
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KNN 分类函数
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@@ -80,36 +79,29 @@ def main():
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scaler = StandardScaler() # 创建标准化对象
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train_data = scaler.fit_transform(train_data) # 对训练数据进行标准化
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# 使用交叉验证选择最佳 k 值
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k_values = range(1, 31) # 定义 k 值范围
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best_k = 1
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best_accuracy = 0
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# 设置 K 值
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k = 1 # 直接定义 K 值为 1
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for k in k_values:
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# 通过手动实现 KNN 分类计算准确率
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correct_predictions = 0
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for i in range(len(train_data)):
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# 留出一条数据作为测试集,其余作为训练集
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test_sample = train_data[i]
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train_subset = np.delete(train_data, i, axis=0)
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train_labels_subset = np.delete(train_labels, i)
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# 手动实现 KNN 分类计算准确率
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correct_predictions = 0
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for i in range(len(train_data)):
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# 留出一条数据作为测试集,其余作为训练集
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test_sample = train_data[i]
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train_subset = np.delete(train_data, i, axis=0)
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train_labels_subset = np.delete(train_labels, i)
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# 使用 KNN 分类器预测
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predicted_label = classify0(test_sample, train_subset, train_labels_subset, k)
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if predicted_label == train_labels[i]:
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correct_predictions += 1
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# 使用 KNN 分类器预测
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predicted_label = classify0(test_sample, train_subset, train_labels_subset, k)
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if predicted_label == train_labels[i]:
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correct_predictions += 1
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accuracy = correct_predictions / len(train_data) # 计算准确性
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if accuracy > best_accuracy:
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best_accuracy = accuracy
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best_k = k
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print(f"最佳 k 值: {best_k},准确率: {best_accuracy:.4f}")
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accuracy = correct_predictions / len(train_data) # 计算准确性
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print(f"使用 K 值 {k} 的准确率: {accuracy:.4f}")
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# 测试分类
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test_sample = [65915, 3.868359, 0.128078] # 测试样本
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test_sample = scaler.transform([test_sample]) # 对测试样本进行相同的缩放
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predicted_label = classify0(test_sample[0], train_data, train_labels, best_k) # 分类
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predicted_label = classify0(test_sample[0], train_data, train_labels, k) # 分类
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print(f"测试样本 {test_sample[0]} 的预测分类标签为: {predicted_label}")
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