diff --git a/function.py b/function.py index bef94d8..95ac2ac 100644 --- a/function.py +++ b/function.py @@ -1,96 +1,70 @@ # function.py -import numpy as np +import numpy as np from sklearn.preprocessing import StandardScaler -from sklearn.metrics import accuracy_score -""" -实验说明: -- 自行编写实现数据加载与预测病马死亡的对率回归算法。 +from sklearn.metrics import accuracy_score -注意事项: -- 在 function.py 中实现对率回归算法。 -- 可以自行导入其他库,需要在 requirements.txt 添加依赖,若未在 requirements.txt 中添加使用到的依赖,则无法自动评测,成绩为零。 -- 自动评测脚本仅会加载 train_logreg、predict_logreg 和 load_data 函数,请勿修改函数名。 +# 学号和姓名 +id = "202210423223" +name = "李顺潮" -测评环境: -- CPU: Intel Xeon(R) CPU E3-1231 v3 @ 3.40GHz -- OS: Ubuntu 22.04.4 LTS -- Python: 3.10.12 -- numpy: 2.1.1 -""" - - -""" -请在这里填写学号和姓名,不填写即成绩无效 -""" -id = "202210423223" -name = "李顺潮" - - -# 这里写自己的代码实现 -def train_logreg(X, y, learning_rate=0.01, iterations=1000, lambda_reg=0.1): +def train_logreg(X, y, learning_rate=0.01, iterations=1000, lambda_reg=0.1): m, n = X.shape weights = np.zeros(n) bias = 0 - + for _ in range(iterations): linear_output = np.dot(X, weights) + bias y_predicted = 1 / (1 + np.exp(-linear_output)) - + # 计算梯度(包括正则化项) dw = (1 / m) * np.dot(X.T, (y_predicted - y)) + (lambda_reg / m) * weights db = (1 / m) * np.sum(y_predicted - y) - + # 更新权重和偏置 weights -= learning_rate * dw bias -= learning_rate * db - + return weights, bias -def predict_logreg(inX, weights, bias): +def predict_logreg(inX, weights, bias): linear_output = np.dot(inX, weights) + bias - y_predicted = 1 if linear_output >= 0 else 0 # 简化阈值判断,因为已经通过sigmoid函数输出 - # 注意:这里为了与原始代码保持一致,使用了0.5作为阈值,但实际上由于sigmoid输出范围在(0,1),可以直接比较linear_output和0 - # return 1 if y_predicted >= 0.5 else 0 # 等价于上面的判断,但多余计算了sigmoid - return y_predicted + y_predicted = 1 if linear_output >= 0 else 0 + return y_predicted -# 这里也写自己的代码实现 -def load_data(filepath): +def load_data(filepath): data = [] with open(filepath, 'r') as file: for line in file: parts = line.strip().split() - # 将缺失值'?'替换为np.nan,然后使用0填充(或选择其他适当的填充策略) features = [float(part) if part != '?' else np.nan for part in parts[:-1]] - # 填充NaN值(这里选择0,但也可以考虑使用均值、中位数等) features = np.nan_to_num(features, nan=0.0) - # 将标签从2转换为1(如果原始标签是1和2的话),这里假设标签已经是0和1 - label = int(parts[-1]) # 假设标签已经是0和1,无需转换 + label = int(parts[-1]) data.append(features + [label]) - + data_array = np.array(data) X = data_array[:, :-1] y = data_array[:, -1] - - # 特征缩放(标准化) + + # 特征缩放 scaler = StandardScaler() X_scaled = scaler.fit_transform(X) - - return X_scaled, y + + return X_scaled, y -if __name__ == "__main__": +if __name__ == "__main__": # 加载训练集和测试集 X_train, y_train = load_data("./data/horse-colic.data") X_test, y_test = load_data("./data/horse-colic.test") - - # 训练对率回归模型 + + # 训练模型 weights, bias = train_logreg(X_train, y_train, learning_rate=0.01, iterations=1000, lambda_reg=0.1) - + # 测试模型并评估性能 y_pred = [predict_logreg(x, weights, bias) for x in X_test] accuracy = accuracy_score(y_test, y_pred) print(f"模型准确率: {accuracy}") - - # 打印单个测试样本的预测结果和实际结果(示例) - # 注意:索引11可能需要根据实际测试集调整,这里仅作为示例 - sample_index = 11 # 假设要测试的样本索引是11(注意:索引可能需要根据实际数据调整) - print(f"预测结果: {y_pred[sample_index]}, 实际结果: {y_test[sample_index]}") \ No newline at end of file + + # 如果测试样本有效 + if len(y_test) > 11: + sample_index = 11 + print(f"预测结果: {y_pred[sample_index]}, 实际结果: {y_test[sample_index]}") \ No newline at end of file