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1355057050 | ||
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47b5945e38 |
+52
-57
@@ -1,7 +1,7 @@
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# function.py
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import numpy as np
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import os
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from scipy.spatial import distance
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"""
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实验说明:
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- 自行编写实现数据加载与 kNN 的手写数字分类算法。
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@@ -25,10 +25,10 @@ import os
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"""
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请在这里填写学号和姓名,不填写即成绩无效。
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"""
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id = "202210423xxx"
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name = "test_name"
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id = "202210423224"
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name = "吴杨洋"
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"""
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参数说明:
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- input_vector (numpy array): 输入待分类的样本。
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@@ -40,8 +40,9 @@ name = "test_name"
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"""
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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=0):
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def classify(input_vector, dataSet, labels, k=3):
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"""
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KNN 分类算法。
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@@ -49,17 +50,33 @@ def classify(input_vector, dataSet, labels, k=0):
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- input_vector (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,请**自行设置默认值**,评测时仅会使用其默认值,不修改默认值将**无法通过**评测,**成绩为零**。
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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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# 计算输入向量与数据集中每个向量的欧氏距离
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distances = [distance.euclidean(input_vector, row) for row in dataSet]
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# 获取距离最近的k个样本的索引
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k_indices = np.argsort(distances)[:k]
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# 获取这些样本对应的标签
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k_nearest_labels = [labels[index] for index in k_indices]
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# 统计每个类别的出现次数
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class_count = {}
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for vote in k_nearest_labels:
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class_count[vote] = class_count.get(vote, 0) + 1
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# 预测的类别是出现次数最多的类别
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predicted_class = max(class_count, key=class_count.get)
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return predicted_class
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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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"""
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从文件夹中加载数据,若不自行正确实现,则无法通过评测,**不记录成绩**。
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从文件夹中加载数据。
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Args:
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- directory (str): 数据文件夹路径。
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@@ -68,13 +85,21 @@ def load_dataset(directory):
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- np.array: 特征数据。
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- np.array: 标签数据。
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"""
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training_file_list = os.listdir(directory)
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training_matrix = []
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training_labels = []
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for file in training_file_list:
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class_num = int(file.split('_')[0])
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vector = img_to_vector(os.path.join(directory, file))
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training_matrix.append(vector)
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training_labels.append(class_num)
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return np.array(training_matrix), np.array(training_labels)
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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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该部分应为 load_dataset 函数的辅助子函数,可单独在这里实现,也可直接集成至 load_dataset 函数中。
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Args:
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- filename (str): 图像文件路径。
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@@ -82,50 +107,20 @@ def img_to_vector(filename):
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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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return_vec = np.zeros((1024,))
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with open(filename) as fr:
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lines = fr.readlines()
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for i in range(32):
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line_str = str(lines[i])
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for j in range(32):
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if line_str[j] == '1':
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return_vec[32*i + j] = 1
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else:
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return_vec[32*i + j] = 0
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return return_vec
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if __name__ == "__main__":
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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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test_data = (
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"00000000000000110000000000000000"
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"00000000000011111000000000000000"
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"00000000000011111100000000000000"
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"00000000001111111110000000000000"
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"00000000001111111110000000000000"
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"00000000001111111100000000000000"
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"00000000011111111000000000000000"
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"00000000111111111000000000000000"
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"00000000111111110000000000000000"
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"00000000111111110000000000000000"
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"00000000111111110000000000000000"
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"00000000111111110000000000000000"
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"00000000111111100000000000000000"
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"00000001111111100000000000000000"
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"00000001111111100000000000000000"
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"00000001111111100000000000000000"
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"00000001111111111111000000000000"
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"00000001111111111111111000000000"
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"00000001111111111111111100000000"
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"00000011111111111111111110000000"
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"00000011111111111111111110000000"
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"00000001111111111111111110000000"
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"00000001111111111111111110000000"
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"00000000111111111100111111100000"
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"00000000111111111000111111100000"
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"00000000011111111001111111100000"
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"00000000011111111111111111000000"
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"00000000001111111111111111000000"
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"00000000000111111111111111000000"
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"00000000000011111111111100000000"
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"00000000000001111111110000000000"
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"00000000000000000111100000000000"
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)
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predicted_label = classify(
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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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train_labels,
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)
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print(f"预测的标签: {predicted_label}")
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this_digit = img_to_vector('testDigits/0_13.txt')
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test_result = classify(this_digit, train_data, train_labels)
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print(test_result)
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@@ -1,2 +1,3 @@
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numpy==2.1.1
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requests==2.32.3
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scipy==1.13.1
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