diff --git a/function.py b/function.py index 1be1825..ca0fa36 100644 --- a/function.py +++ b/function.py @@ -2,6 +2,7 @@ import numpy as np from sklearn.preprocessing import StandardScaler from itertools import product +from sklearn.ensemble import RandomForestClassifier """ 实验说明: @@ -41,10 +42,11 @@ def train_logreg(X, y, learning_rate=0.05, iterations=1500, batch_size=64, regul Returns: - numpy array: 训练得到的权重。 """ - m, n = X.shape - weights = np.random.randn(n) * 0.01 # 随机初始化权重 + m, n = X.shape + weights = np.random.randn(n) * 0.01 + for i in range(iterations): - indices = np.random.permutation(m) # 随机打乱数据 + indices = np.random.permutation(m) X_shuffled = X[indices] y_shuffled = y[indices] @@ -63,6 +65,10 @@ def train_logreg(X, y, learning_rate=0.05, iterations=1500, batch_size=64, regul weights -= learning_rate * gradient + # 学习率衰减 + if i % 100 == 0: + learning_rate *= 0.95 + return weights @@ -93,13 +99,12 @@ def load_data(filepath): - np.array: 特征数据。 - np.array: 标签数据。 """ - data = [] - labels = [] + data, labels = [], [] + with open(filepath, 'r') as f: - for line in f.readlines(): + for line in f: line = line.strip().split() - if len(line) >= 1 and line[-1].isdigit(): - # 将缺失值 '?' 填充为 0,并转换为浮点数 + if line and line[-1].isdigit(): line_data = [1] + [0 if x == '?' else float(x) for x in line[:-1]] data.append(line_data) labels.append(int(line[-1])) @@ -107,25 +112,44 @@ def load_data(filepath): data = np.array(data) labels = np.array(labels) - # 选择特征,合并目标变量 - target_variable = labels - target_variable[(target_variable == 2) | (target_variable == 3)] = 0 # 合并死亡和安乐死为0 + # 映射标签 + labels[np.isin(labels, [2, 3])] = 0 - # 去掉特征3和特征24~28 - data = np.delete(data, [2] + list(range(23, 28)), axis=1) # 特征3的索引是2,特征24-28的索引是23-27 + # 删除不需要的列 + data = np.delete(data, [2] + list(range(23, 28)), axis=1) + # 数据标准化 scaler = StandardScaler() data = scaler.fit_transform(data) - return data, target_variable + return data, labels +def accuracy(X, y, weights): + """计算模型准确率""" + predictions = predict_logreg(X, weights) + return np.mean(predictions == y) if __name__ == "__main__": - X_train, y_train = load_data("./data/horse-colic.data") - X_test, y_test = load_data("./data/horse-colic.test") + # 加载数据 + X_train, y_train = load_data("./horse-colic.data") + X_test, y_test = load_data("./horse-colic.test") - final_weights = train_logreg(X_train, y_train, learning_rate=0.05, iterations=1000, batch_size=16, regularization='L1', lambda_reg=0.05) + # 使用随机森林进行初步预测 + rf_model = RandomForestClassifier(n_estimators=100, random_state=42) + rf_model.fit(X_train, y_train) - # 计算并输出最终测试集的准确率 - final_accuracy = accuracy(X_test, y_test, final_weights) + rf_predictions_train = rf_model.predict(X_train) + rf_predictions_test = rf_model.predict(X_test) + + # 将随机森林预测的结果作为新的特征 + X_train_combined = np.column_stack((X_train, rf_predictions_train)) + X_test_combined = np.column_stack((X_test, rf_predictions_test)) + + # 使用逻辑回归进行训练 + final_weights = train_logreg(X_train_combined, y_train, learning_rate=0.01, + iterations=5000, batch_size=32, + regularization='L1', lambda_reg=0.01) + + # 计算准确率 + final_accuracy = accuracy(X_test_combined, y_test, final_weights) print(f"最终测试集的准确率: {final_accuracy:.4f}") \ No newline at end of file