diff --git a/function.py b/function.py index 1b74ab2..6a84b05 100644 --- a/function.py +++ b/function.py @@ -26,104 +26,49 @@ name = "黎世浩" def load_data(filepath): - """ - 从文件中加载数据,若不自行正确实现,则无法通过评测,**不记录成绩**。 - - Args: - - filepath (str): 数据文件路径。 - - Returns: - - np.array: 特征数据。 - - np.array: 标签数据。 - """ - # 读取数据,将非数值转换为NaN data = np.genfromtxt(filepath, delimiter=' ', dtype=float, missing_values='?') - - # 分离特征和标签 X = data[:, :-1] y = data[:, -1] - + # 将缺失值填充为每列的平均值 for i in range(X.shape[1]): - X[:, i] = np.where(np.isnan(X[:, i]), np.nanmean(X[:, i]), X[:, i]) - + X[:, i] = np.where(np.isnan(X[:, i]), np.mean(X[:, i]), X[:, i]) + return X, y.astype(int) def scale_features(X): - """ - 对特征进行标准化处理。 - - Args: - - X (numpy array): 特征数据。 - - Returns: - - numpy array: 标准化后的特征数据。 - """ mean = np.mean(X, axis=0) std = np.std(X, axis=0) - # 避免除以零的错误 std[std == 0] = 1 scaled_X = (X - mean) / std return scaled_X -def train_logreg(X, y, learning_rate=0.01, iterations=1000): - """ - 对率回归训练函数。 - - Args: - - X (numpy array): 特征数据。 - - y (numpy array): 标签数据。 - - learning_rate (float): 学习率,默认为0.01。 - - iterations (int): 迭代次数,默认为1000。 - - Returns: - - numpy array: 训练得到的权重。 - """ +def train_logreg(X, y, learning_rate=0.01, iterations=1000, lambda_reg=0.01): m, n = X.shape weights = np.zeros(n) - for _ in range(iterations): for i in range(m): x_i = X[i] y_i = y[i] - # 计算预测值 prediction = 1 / (1 + np.exp(-np.dot(x_i, weights))) - # 计算梯度 gradient = x_i * (prediction - y_i) - # 更新权重 - weights -= learning_rate * gradient - + weights -= learning_rate * (gradient + lambda_reg * weights) return weights def predict_logreg(inX, weights): - """ - 对率回归预测函数。 - - Args: - - inX (numpy array): 输入待分类的样本。 - - weights (numpy array): 训练得到的权重。 - - Returns: - - int: 预测的分类标签。 - """ prediction = 1 / (1 + np.exp(-np.dot(inX, weights))) return 1 if prediction > 0.5 else 0 if __name__ == "__main__": - # 以下代码可用于测试,可自行随意修改 - # 加载训练集 X_train, y_train = load_data("./data/horse-colic.data") - - # 加载测试集 X_test, y_test = load_data("./data/horse-colic.test") - - # 特征缩放 + X_train_scaled = scale_features(X_train) X_test_scaled = scale_features(X_test) - - # 训练对率回归模型 + weights = train_logreg(X_train_scaled, y_train, learning_rate=0.01, iterations=1000) - - # 测试单个数据 - y_pred = predict_logreg(X_test_scaled[11], weights) - print(f"预测结果: {y_pred}, 实际结果: {y_test[11]}") \ No newline at end of file + + # 测试模型 + y_pred = [predict_logreg(x, weights) for x in X_test_scaled] + accuracy = np.mean(y_pred == y_test) + print(f"Accuracy: {accuracy}") \ No newline at end of file