generated from LufsX/Experiment-kNN
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# function.py
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# function.py
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import numpy as np
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import numpy as np
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import os
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import os
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from collections import Counter
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"""
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"""
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实验说明:
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实验说明:
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@@ -41,41 +40,90 @@ name = "邓龙树"
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"""
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"""
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# KNN 分类算法
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# 这里写自己的代码实现
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def classify(input_vector, dataSet, labels, k=3):
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import numpy as np
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# 计算输入向量与训练集中每个样本的距离
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import os
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distances = [np.linalg.norm(input_vector - data) for data in dataSet]
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from collections import Counter
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# 根据距离排序并获取前 k 个标签
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k_indices = np.argsort(distances)[:k]
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k_labels = [labels[index] for index in k_indices]
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# 对 k 个标签进行投票,返回出现次数最多的标签
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vote = Counter(k_labels).most_common(1)[0][0]
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return vote
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# 这里写自己的代码实现
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def classify(input_vector, dataSet, labels, k=3):
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"""
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使用 KNN 算法对输入样本进行分类。
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参数:
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- input_vector (numpy array): 输入待分类的样本(1xN)。
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- dataSet (numpy array): 训练数据集(MxN)。
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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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返回:
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- int: 预测的分类标签。
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"""
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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.sum((input_vector - dataSet) ** 2, axis=1) ** 0.5
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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]].tolist() # 将 NumPy 数组转换为列表
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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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# 从文件夹中加载数据
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# 这里也写自己的代码实现
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def load_dataset(directory):
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def load_dataset(directory):
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"""
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加载数据集中的图像,并将其转换为特征向量和标签。
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参数:
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- directory (str): 数据文件夹路径。
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返回:
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- np.array: 特征数据(Mx1024)。
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- np.array: 标签数据(Mx1)。
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"""
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# 初始化特征数据列表和标签列表
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feature_list = []
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feature_list = []
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label_list = []
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label_list = []
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# 遍历目录中的所有文件
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for file in os.listdir(directory):
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for file in os.listdir(directory):
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# 获取文件的完整路径
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file_path = os.path.join(directory, file)
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file_path = os.path.join(directory, file)
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feature = img_to_vector(file_path)
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# 将图像文件转换为向量
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label = int(file.split('_')[0])
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feature_vector = img_to_vector(file_path)
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feature_list.append(feature)
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# 将特征向量添加到列表中
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label_list.append(label)
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feature_list.append(feature_vector)
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return np.array(feature_list), np.array(label_list)
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# 获取文件名中的标签并添加到标签列表中
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label_list.append(int(file.split('_')[0]))
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# 将特征列表和标签列表转换为numpy数组
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# 将二值图像转换为向量
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feature_matrix = np.array(feature_list)
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def img_to_vector(filename):
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label_array = np.array(label_list)
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with open(filename, 'r') as f:
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return feature_matrix, label_array
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return np.array([int(char) for char in f.read().strip()])
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# 这里还写自己的代码实现
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def img_to_vector(filename):
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"""
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将二值图像转换为向量。
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Args:
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- filename (str): 图像文件路径。
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Returns:
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- np.array: 二值图像向量。
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"""
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# 初始化向量
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vector = np.zeros((1024,)) # 创建一个一维数组
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# 打开文件并逐行读取
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with open(filename) as file:
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for i, line in enumerate(file):
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# 将每行的数字字符转换为整数并存储到向量中
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vector[i*32:i*32+32] = np.array([int(char) for char in line.strip()])
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return vector
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if __name__ == "__main__":
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if __name__ == "__main__":
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#加载训练数据
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# 以下代码可用于测试,可自行随意修改
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train_data, train_labels = load_dataset("trainingDigits")
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train_data, train_labels = load_dataset("trainingDigits")
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#测试数据
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test_data = (
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test_data = (
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"00000000000000110000000000000000"
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"00000000000000110000000000000000"
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"00000000000011111000000000000000"
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"00000000000011111000000000000000"
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@@ -110,9 +158,11 @@ if __name__ == "__main__":
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"00000000000001111111110000000000"
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"00000000000001111111110000000000"
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"00000000000000000111100000000000"
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"00000000000000000111100000000000"
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)
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)
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# 将测试数据转换为向量
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predicted_label = classify(
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test_vector = np.array([int(char) for char in test_data]).reshape(1, 1024)
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np.array([int(char) for char in test_data]).reshape(1, 1024),
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train_data,
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# 进行分类预测
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train_labels,
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predicted_label = classify(test_vector, train_data, train_labels)
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)
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print(f"预测的标签: {predicted_label}")
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print(f"预测的标签: {predicted_label}")
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