diff --git a/function.py b/function.py index 694e6d4..9a3d930 100644 --- a/function.py +++ b/function.py @@ -32,14 +32,14 @@ def sigmoid(z): """计算sigmoid函数""" return 1 / (1 + np.exp(-z)) -def train_logreg(X, y, learning_rate=0.01, iterations=1000): +def train_logreg(X, y, learning_rate=0.01, iterations=1000,l2_penalty=0.01): """对率回归训练函数。""" weights = np.zeros(X.shape[1]) for _ in range(iterations): z = np.dot(X, weights) predictions = sigmoid(z) - gradient = np.dot(X.T, (predictions - y)) / y.size + gradient = np.dot(X.T, (predictions - y)) / y.size + l2_penalty * weights # 添加L2正则化项 weights -= learning_rate * gradient return weights @@ -84,6 +84,18 @@ def load_data(filepath): return data_array[:, :-1], data_array[:, -1] def preprocess_data(X, y): + """数据预处理,合并特征23的值,并删除特征3和特征24~28,以及特征缩放。""" + # 合并特征23的值和删除特征 + X, y = preprocess_data_base(X, y) + + # 特征缩放:标准化特征 + X_mean = np.mean(X, axis=0) + X_std = np.std(X, axis=0) + X = (X - X_mean) / X_std + + return X, y + +def preprocess_data_base(X, y): """数据预处理,合并特征23的值,并删除特征3和特征24~28。""" # 合并特征23的值:将2(死亡)和3(安乐死)合并为0(死亡) y = np.where(y == 2, 0, y) # 将值2替换为0 @@ -101,8 +113,8 @@ if __name__ == "__main__": # 数据预处理 X, y = preprocess_data(X, y) - # 训练模型 - weights = train_logreg(X, y) + # 训练模型 + weights = train_logreg(X, y, learning_rate=0.01, l2_penalty=0.01) # 加载测试数据并进行预处理 X_test, y_test = load_data("./data/horse-colic.test")