import numpy as np id = "202210423224" name = "吴杨洋" def sigmoid(z): return 1 / (1 + np.exp(-np.clip(z, -500, 500))) def train_logreg(X, y, numIter=1 + 1000, learning_rate=0.01, lambda_reg=0.01): m, n = X.shape weights = np.zeros(n) for j in range(numIter): for i in range(m): z = np.dot(X[i], weights) h = sigmoid(z) error = y[i] - h gradient = X[i] * error reg_term = lambda_reg * weights gradient += reg_term weights -= learning_rate * gradient return weights def predict_logreg(inX, weights): z = np.dot(inX, weights) prob = sigmoid(z) return 1 if prob >= 0.5 else 0 def load_data(filepath): file = open(filepath) fr = file.readlines() data_list = [] y = [] for data in fr: data = data.strip() data = data.split() if len(data) < 25: # 确保每行数据有足够的元素 continue y.append(int(data[22]) > 1) # 假设标签是 0 或 1 data_25 = data[24] # 删除不需要的元素 del data[0], data[1], data[2], data[22], data[24], data[25] for i in data_25.split(','): data.append(i) # 将 '?' 替换为 0 data = [0 if x == '?' else float(x) for x in data] data_list.append(data) data_number = len(y) y_train = np.array(y) X = np.array(data_list) return X, y_train def standardize(X): mean = X.mean(axis=0) std = X.std(axis=0) return (X - mean) / std, mean, std def main(): X_train, y_train = load_data("./data/horse-colic.data") X_test, y_test = load_data("./data/horse-colic.test") X_train, mean, std = standardize(X_train) X_test = (X_test - mean) / std weights = train_logreg(X_train, y_train, numIter=1000, learning_rate=0.01, lambda_reg=0.1) y_pred_test = [predict_logreg(x, weights) for x in X_test] accuracy_test = np.mean(y_pred_test == y_test) print(f"Test Accuracy: {accuracy_test:.2f}") if __name__ == "__main__": main()