diff --git a/function.py b/function.py index 9a7f323..01add2a 100644 --- a/function.py +++ b/function.py @@ -31,24 +31,21 @@ name = "严锡好" # 这里写自己的代码实现 -# sigmoid函数,用于逻辑回归模型中将线性输出转换为概率 -def sigmoid(x): - return 1 / (1 + np.exp(-x)) +def sigmoid(z): + return 1.0 / (1 + np.exp(-z)) -# 计算梯度的函数 def compute_gradient(X_batch, y_batch, weights, lambda_reg): z = np.dot(X_batch, weights) h = sigmoid(z) gradient = np.dot(X_batch.T, (h - y_batch)) / len(y_batch) - gradient += lambda_reg * weights # L2正则化 + gradient += (lambda_reg / len(y_batch)) * weights # L2正则化 return gradient -# train_logreg函数,用于训练逻辑回归模型 -def train_logreg(X, y, learning_rate=0.01, iterations=1000, batch_size=64, lambda_reg=0.1): +def train_logreg(X, y, learning_rate=0.001, iterations=10000, batch_size=64, lambda_reg=0.1): m, n = X.shape - weights = np.zeros(n) - best_accuracy = 0 + weights = np.random.randn(n) * np.sqrt(2. / n) # He初始化 best_weights = weights.copy() + best_accuracy = 0 for i in range(iterations): indices = np.random.permutation(m) @@ -61,25 +58,21 @@ def train_logreg(X, y, learning_rate=0.01, iterations=1000, batch_size=64, lambd gradient = compute_gradient(X_batch, y_batch, weights, lambda_reg) weights -= learning_rate * gradient - # 计算训练集准确率 accuracy = accuracy_score(y, predict_logreg(X, weights)) if accuracy > best_accuracy: best_accuracy = accuracy best_weights = weights.copy() - # 动态调整学习率 - if i % 100 == 0 and accuracy > 0.95: # 达到高准确率时减小学习率 + if i % 1000 == 0 and accuracy > 0.95: # 动态调整学习率 learning_rate *= 0.9 return best_weights -# predict_logreg函数,用于使用训练好的权重进行预测 -def predict_logreg(inX, weights): - linear_output = np.dot(inX, weights) - probability = sigmoid(linear_output) - return np.where(probability > 0.5, 1, 0) +def predict_logreg(X, weights): + z = np.dot(X, weights) + h = sigmoid(z) + return np.where(h >= 0.5, 1, 0) -# preprocess_data函数,用于预处理数据 def preprocess_data(X, y): y[y == 2] = 0 y[y == 3] = 0 @@ -87,7 +80,6 @@ def preprocess_data(X, y): X = X[:, :23] return X, y -# load_data函数,用于加载数据 def load_data(filepath): try: data = pd.read_csv(filepath, header=None, sep=r'\s+', on_bad_lines='skip') @@ -104,28 +96,33 @@ def load_data(filepath): X, y = preprocess_data(X, y) return X, y -# main函数,程序的入口点 -def main(): - X, y = load_data("./data/horse-colic.data") - if X is not None: - # 分割数据集为训练集和测试集 - X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42) - - # 特征缩放 - scaler = StandardScaler() - X_train = scaler.fit_transform(X_train) - X_test = scaler.transform(X_test) - - # 训练模型 - weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=1000, batch_size=64, lambda_reg=0.1) - - # 预测测试集 - y_pred = predict_logreg(X_test, weights) - - # 计算准确率 - accuracy = accuracy_score(y_test, y_pred) - print(f"准确率: {accuracy}") - print(classification_report(y_test, y_pred)) - if __name__ == "__main__": - main() \ No newline at end of file + # 加载数据 + X, y = load_data("./data/horse-colic.data") + + # 拆分训练集和验证集 + X_train, X_val, y_train, y_val = train_test_split(X, y, test_size=0.2, random_state=42) + + # 数据归一化 + scaler = MinMaxScaler() + X_train = scaler.fit_transform(X_train) + X_val = scaler.transform(X_val) + + # 训练模型 + final_weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=5000, batch_size=64, lambda_reg=0.1) + + # 验证模型 + y_pred = predict_logreg(X_val, final_weights) + val_accuracy = accuracy_score(y_val, y_pred) + print(f"验证集的准确率: {val_accuracy:.4f}") + print(classification_report(y_val, y_pred)) + + # 加载测试集 + X_test, y_test = load_data("./data/horse-colic.test") + X_test = scaler.transform(X_test) + + # 测试模型 + y_test_pred = predict_logreg(X_test, final_weights) + test_accuracy = accuracy_score(y_test, y_test_pred) + print(f"最终测试集的准确率: {test_accuracy:.4f}") + print(classification_report(y_test, y_test_pred)) \ No newline at end of file