generated from LufsX/Challenge-kNN
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@@ -46,8 +46,19 @@ name = "陈瑞琪祥"
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def classify0(inX, dataSet, labels, k):
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def classify0(inX, dataSet, labels, k=3):
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result = classify0(test_data[i], train_data, train_labels, k=3) # 假设 k=3 是你选择的值
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"""
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KNN 分类算法。
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Args:
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- inX (numpy array): 输入待分类的样本。
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- dataSet (numpy array): 训练数据集。
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- labels (list or numpy array): 训练集对应的标签。
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- k (int): kNN 算法参数,默认值为 3。
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Returns:
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- int: 预测的分类标签。
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"""
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diffMat = np.tile(inX, (dataSet.shape[0], 1)) - dataSet
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diffMat = np.tile(inX, (dataSet.shape[0], 1)) - dataSet
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sqDiffMat = diffMat**2
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sqDiffMat = diffMat**2
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sqDistances = sqDiffMat.sum(axis=1)
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sqDistances = sqDiffMat.sum(axis=1)
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@@ -61,26 +72,15 @@ def classify0(inX, dataSet, labels, k):
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return sortedClassCount[0][0]
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return sortedClassCount[0][0]
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def load_data(file_path):
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def load_data(file_path):
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"""
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加载 TSV 格式数据文件,并进行标准化处理。
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"""
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data = np.loadtxt(file_path, delimiter="\t")
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data = np.loadtxt(file_path, delimiter="\t")
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features = data[:, :-1]
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features = data[:, :-1]
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labels = data[:, -1].astype(int)
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labels = data[:, -1].astype(int)
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features = (features - np.mean(features, axis=0)) / np.std(features, axis=0)
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features = (features - np.mean(features, axis=0)) / np.std(features, axis=0)
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return features, labels
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return features, labels
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def find_best_k(train_data, train_labels):
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best_accuracy = 0
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best_k = 1
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for k in range(1, 26, 2): # 尝试奇数的 k 值,从 1 到 25
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correct_count = 0
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for i in range(train_data.shape[0]):
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if classify0(train_data[i], train_data, train_labels, k) == train_labels[i]:
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correct_count += 1
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accuracy = correct_count / train_data.shape[0]
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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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return best_k
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def preprocess_data(features):
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def preprocess_data(features):
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# 简单的异常值处理
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# 简单的异常值处理
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Q1 = np.percentile(features, 25, axis=0)
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Q1 = np.percentile(features, 25, axis=0)
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@@ -99,11 +99,9 @@ if __name__ == "__main__":
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train_data = preprocess_data(train_data)
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train_data = preprocess_data(train_data)
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test_data = preprocess_data(test_data)
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test_data = preprocess_data(test_data)
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best_k = find_best_k(train_data, train_labels)
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correct_count = 0
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correct_count = 0
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for i in range(test_data.shape[0]):
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for i in range(test_data.shape[0]):
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if classify0(test_data[i], train_data, train_labels, best_k) == test_labels[i]:
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if classify0(test_data[i], train_data, train_labels, k=3) == test_labels[i]:
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correct_count += 1
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correct_count += 1
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print(f"Accuracy with best k = {best_k}: {correct_count / test_data.shape[0] * 100:.2f}%")
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print(f"Accuracy: {correct_count / test_data.shape[0] * 100:.2f}%")
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