diff --git a/function.py b/function.py index 14a553a..b61ba01 100644 --- a/function.py +++ b/function.py @@ -26,58 +26,117 @@ name = "廖运瑞" # 这里写自己的代码实现 -def train_logreg(X, y, other_params="你自己设置一些其它参数"): - """ - 对率回归训练函数。 - - Args: - - X (numpy array): 特征数据。 - - y (numpy array): 标签数据。 - - other_params (str): 其它参数,可选设置。若需设置其它参数,必须设置其默认值,否则将**无法通过**自动评测,**成绩为零**。 - - Returns: - - numpy array: 训练得到的权重。 - """ +from sklearn.preprocessing import MinMaxScaler +from sklearn.model_selection import train_test_split -def predict_logreg(inX, weights): - """ - 对率回归预测函数。 +def sigmoid(z): + return 1.0 / (1 + np.exp(-z)) - 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。 - """ +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 / len(y_batch)) * weights # L2正则化 + return gradient + + +def train_logreg(X, y, learning_rate=0.001, iterations=10000, batch_size=64, lambda_reg=0.1): + m, n = X.shape + weights = np.random.randn(n) * np.sqrt(2. / n) # He初始化 + best_weights = weights.copy() + best_accuracy = 0 + + for _ in range(iterations): + indices = np.random.permutation(m) + X_shuffled = X[indices] + y_shuffled = y[indices] + + for j in range(0, m, batch_size): + X_batch = X_shuffled[j:j + batch_size] + y_batch = y_shuffled[j:j + batch_size] + gradient = compute_gradient(X_batch, y_batch, weights, lambda_reg) + weights -= learning_rate * gradient + + # 计算训练集准确率 + train_accuracy = accuracy(X, y, weights) + if train_accuracy > best_accuracy: + best_accuracy = train_accuracy + best_weights = weights.copy() + + # 动态调整学习率 + if _ % 100 == 0 and train_accuracy > 0.95: # 达到高准确率时减小学习率 + learning_rate *= 0.9 + + return best_weights + + +def predict_logreg(X, weights): + z = np.dot(X, weights) + h = sigmoid(z) + return np.where(h >= 0.5, 1, 0) -# 这里也写自己的代码实现 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**。 + data, labels = [], [] + with open(filepath, 'r') as f: + for line in f: + line = line.strip().split() + if len(line) >= 1 and line[-1].isdigit(): + line_data = [0 if x == '?' else float(x) for x in line[:-1]] + data.append(line_data) + labels.append(int(line[-1])) - Args: - - directory (str): 数据文件路径。 + data = np.array(data) + labels = np.array(labels) - Returns: - - np.array: 特征数据。 - - np.array: 标签数据。 - """ + # 检查特征数量 + num_features = data.shape[1] + + # 特征选择:去掉特征3(索引2)和特征24~28(索引23~26),确保索引有效 + indices_to_delete = [2] # 特征3 + if num_features > 24: # 确保特征数量足够 + indices_to_delete += list(range(24, 27)) # 特征24到27(索引23到26) + + # 删除特征 + data = np.delete(data, indices_to_delete, axis=1) + + # 将标签二分类化,特征23(索引22)取值2和3合并为0,其余为1 + target_variable = np.where((labels == 2) | (labels == 3), 0, 1) + + return data, target_variable +def accuracy(X, y, weights): + predictions = predict_logreg(X, weights) + return np.mean(predictions == y) + + +# 其余代码保持不变 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 + val_accuracy = accuracy(X_val, y_val, final_weights) + print(f"验证集的准确率: {val_accuracy:.4f}") # 加载测试集 X_test, y_test = load_data("./data/horse-colic.test") + X_test = scaler.transform(X_test) - # 训练对率回归模型 - weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=1000) - - # 测试单个数据 - y_pred = predict_logreg(X_test[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 + final_test_accuracy = accuracy(X_test, y_test, final_weights) + print(f"最终测试集的准确率: {final_test_accuracy:.4f}")t[11]}") \ No newline at end of file