diff --git a/function.py b/function.py index b128aee..6d70460 100644 --- a/function.py +++ b/function.py @@ -27,59 +27,10 @@ name = "章程鸿" # 这里写自己的代码实现 import numpy as np -from sklearn.preprocessing import StandardScaler - -def sigmoid(z): - """Sigmoid 激活函数。""" - return 1.0 / (1 + np.exp(-z)) - -def train_logreg(X, y, learning_rate=0.05, iterations=1500, batch_size=64, reg_lambda=0.01): - """训练逻辑回归模型的函数,使用梯度下降算法。""" - m, n = X.shape - weights = np.random.randn(n) * 0.01 # 初始化权重 - best_weights = weights.copy() - best_accuracy = 0 - wait = 0 - - for i 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] - z = np.dot(X_batch, weights) - h = sigmoid(z) - gradient = np.dot(X_batch.T, (h - y_batch)) / len(y_batch) + reg_lambda * weights - - 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() - wait = 0 - else: - wait += 1 - - # 如果准确率没有提高,提前停止 - if wait > 50: - break - - return best_weights - -def predict_logreg(X, weights): - """预测函数。""" - z = np.dot(X, weights) - h = sigmoid(z) - return np.where(h > 0.5, 1, 0) - +from sklearn.preprocessing import MinMaxScaler +from sklearn.model_selection import train_test_split def load_data(filepath): - """加载数据函数。""" - data = [] - labels = [] + data, labels = [], [] with open(filepath, 'r') as f: for line in f: line = line.strip().split() @@ -90,34 +41,79 @@ def load_data(filepath): data = np.array(data) labels = np.array(labels) - target_variable = np.where((labels == 2) | (labels == 3), 0, labels) - - n_features = data.shape[1] - columns_to_delete = [2] + list(range(23, min(28, n_features))) - data = np.delete(data, columns_to_delete, axis=1) - - scaler = StandardScaler() - data = scaler.fit_transform(data) - + + # 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): - """计算准确率。""" - predictions = predict_logreg(X, weights) - return np.mean(predictions == y) +def load_data(filepath): + 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])) + data = np.array(data) + labels = np.array(labels) + + # 检查特征数量 + num_features = data.shape[1] + print(f"特征数量: {num_features}") + + # 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 + + + +# 其余代码保持不变 if __name__ == "__main__": - X_train, y_train = load_data("./horse-colic.data") - X_test, y_test = load_data("./horse-colic.test") + # 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) - # 特征标准化 - scaler = StandardScaler() + # 数据归一化 + scaler = MinMaxScaler() X_train = scaler.fit_transform(X_train) - X_test = scaler.transform(X_test) + X_val = scaler.transform(X_val) # 训练模型 - final_weights = train_logreg(X_train, y_train, learning_rate=0.001, iterations=1500, batch_size=64, reg_lambda=0.01) + final_weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=5000, batch_size=64, lambda_reg=0.1) - # 计算测试集准确率 - final_accuracy = accuracy(X_test, y_test, final_weights) - print(f"最终测试集的准确率: {final_accuracy:.4f}") + # 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) + + # 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}") \ No newline at end of file