diff --git a/function.py b/function.py index b1f8c16..a872187 100644 --- a/function.py +++ b/function.py @@ -1,7 +1,7 @@ # function.py import numpy as np import os - +from scipy.spatial import distance """ 实验说明: - 自行编写实现数据加载与 kNN 的手写数字分类算法。 @@ -25,8 +25,8 @@ import os """ 请在这里填写学号和姓名,不填写即成绩无效。 """ -id = "202210423xxx" -name = "test_name" +id = "202210423224" +name = "吴杨洋" """ @@ -40,8 +40,8 @@ name = "test_name" """ -# 这里写自己的代码实现 -def classify(input_vector, dataSet, labels, k=0): + +def classify(input_vector, dataSet, labels, k=3): """ KNN 分类算法。 @@ -49,17 +49,33 @@ def classify(input_vector, dataSet, labels, k=0): - input_vector (numpy array): 输入待分类的样本。 - dataSet (numpy array): 训练数据集。 - labels (list or numpy array): 训练集对应的标签。 - - 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**。 + - k (int): kNN 算法参数,默认值为3。 Returns: - int: 预测的分类标签。 """ + # 计算输入向量与数据集中每个向量的欧氏距离 + distances = [distance.euclidean(input_vector, row) for row in dataSet] + + # 获取距离最近的k个样本的索引 + k_indices = np.argsort(distances)[:k] + + # 获取这些样本对应的标签 + k_nearest_labels = [labels[index] for index in k_indices] + + # 统计每个类别的出现次数 + class_count = {} + for vote in k_nearest_labels: + class_count[vote] = class_count.get(vote, 0) + 1 + + # 预测的类别是出现次数最多的类别 + predicted_class = max(class_count, key=class_count.get) + + return predicted_class - -# 这里也写自己的代码实现 def load_dataset(directory): """ - 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**。 + 从文件夹中加载数据。 Args: - directory (str): 数据文件夹路径。 @@ -68,13 +84,21 @@ def load_dataset(directory): - np.array: 特征数据。 - np.array: 标签数据。 """ + training_file_list = os.listdir(directory) + training_matrix = [] + training_labels = [] + + for file in training_file_list: + class_num = int(file.split('_')[0]) + vector = img_to_vector(os.path.join(directory, file)) + training_matrix.append(vector) + training_labels.append(class_num) + + return np.array(training_matrix), np.array(training_labels) - -# 这里还写自己的代码实现 def img_to_vector(filename): """ 将二值图像转换为向量。 - 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。 Args: - filename (str): 图像文件路径。 @@ -82,50 +106,20 @@ def img_to_vector(filename): Returns: - np.array: 二值图像向量。 """ - + return_vec = np.zeros((1024,)) + with open(filename) as fr: + lines = fr.readlines() + for i in range(32): + line_str = str(lines[i]) + for j in range(32): + if line_str[j] == '1': + return_vec[32*i + j] = 1 + else: + return_vec[32*i + j] = 0 + return return_vec if __name__ == "__main__": - # 以下代码可用于测试,可自行随意修改 train_data, train_labels = load_dataset("trainingDigits") - - test_data = ( - "00000000000000110000000000000000" - "00000000000011111000000000000000" - "00000000000011111100000000000000" - "00000000001111111110000000000000" - "00000000001111111110000000000000" - "00000000001111111100000000000000" - "00000000011111111000000000000000" - "00000000111111111000000000000000" - "00000000111111110000000000000000" - "00000000111111110000000000000000" - "00000000111111110000000000000000" - "00000000111111110000000000000000" - "00000000111111100000000000000000" - "00000001111111100000000000000000" - "00000001111111100000000000000000" - "00000001111111100000000000000000" - "00000001111111111111000000000000" - "00000001111111111111111000000000" - "00000001111111111111111100000000" - "00000011111111111111111110000000" - "00000011111111111111111110000000" - "00000001111111111111111110000000" - "00000001111111111111111110000000" - "00000000111111111100111111100000" - "00000000111111111000111111100000" - "00000000011111111001111111100000" - "00000000011111111111111111000000" - "00000000001111111111111111000000" - "00000000000111111111111111000000" - "00000000000011111111111100000000" - "00000000000001111111110000000000" - "00000000000000000111100000000000" - ) - predicted_label = classify( - np.array([int(char) for char in test_data]).reshape(1, 1024), - train_data, - train_labels, - ) - - print(f"预测的标签: {predicted_label}") + this_digit = img_to_vector('testDigits/0_13.txt') + test_result = classify(this_digit, train_data, train_labels) + print(test_result)