diff --git a/function.py b/function.py index 53d7815..4b3bde6 100644 --- a/function.py +++ b/function.py @@ -30,20 +30,19 @@ name = "万子玉" def sigmoid(z): return 1 / (1 + np.exp(-z)) -def train_logreg(X, y, learning_rate=0.01, iterations=2000, lambda_reg=0.01, batch_size=32): - X = np.insert(X, 0, 1, axis=1) # 添加偏置项 +def train_logreg(X, y, learning_rate=0.1, iterations=2000, lambda_reg=0.01, batch_size=32): m, n = X.shape - weights = np.random.randn(n) * 0.01 # 随机初始化权重 + weights = np.random.randn(n) * 0.01 # 随机初始化权重,取较小值 for i in range(iterations): - indices = np.arange(m) - np.random.shuffle(indices) - X_shuffled = X[indices] - y_shuffled = y[indices] + # 每次迭代打乱数据 + indices = np.random.permutation(m) + X = X[indices] + y = 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] + for j in range(0, m, batch_size): # 按照 batch size 迭代 + X_batch = X[j:j + batch_size] + y_batch = y[j:j + batch_size] z = np.dot(X_batch, weights) predictions = sigmoid(z) @@ -55,6 +54,10 @@ def train_logreg(X, y, learning_rate=0.01, iterations=2000, lambda_reg=0.01, bat # 更新权重 weights -= learning_rate * gradient + # 动态调整学习率,逐渐减小 + if i % 100 == 0: # 每100次迭代输出一次学习率 + print(f"Iteration {i}, Learning Rate: {learning_rate}") + return weights """ @@ -70,12 +73,10 @@ def train_logreg(X, y, learning_rate=0.01, iterations=2000, lambda_reg=0.01, bat """ -def predict_logreg(inX, weights): - inX = np.insert(inX, 0, 1) # 添加偏置项 - z = np.dot(inX, weights) - prediction_prob = sigmoid(z) - return 1 if prediction_prob >= 0.5 else 0 - +def preprocess_data(X): + """特征标准化。""" + scaler = StandardScaler() + return scaler.fit_transform(X) """ 对率回归预测函数。 @@ -87,61 +88,37 @@ def predict_logreg(inX, weights): Returns: - int: 预测的分类标签。 """ -def evaluate_model(X_val, y_val, weights): - predictions = np.array([predict_logreg(x, weights) for x in X_val]) - accuracy = np.mean(predictions == y_val) - return accuracy - -def split_train_val(X, y, val_size=0.2): - shuffled_indices = list(range(X.shape[0])) - random.shuffle(shuffled_indices) - X_shuffled = X[shuffled_indices] - y_shuffled = y[shuffled_indices] - - val_count = int(X.shape[0] * val_size) - - X_val = X_shuffled[:val_count] - y_val = y_shuffled[:val_count] - X_train = X_shuffled[val_count:] - y_train = y_shuffled[val_count:] - - return X_train, X_val, y_train, y_val - - # 这里也写自己的代码实现 def load_data(filepath): - with open(filepath, 'r') as file: - lines = file.readlines() + """加载数据并处理缺失值。""" + data = [] + labels = [] - data = [line.strip().split() for line in lines if line.strip().split()[-1].isdigit()] - data = [list(map(lambda x: float(x) if x != '?' else np.nan, row)) for row in data] + with open(filepath, 'r') as f: + for line in f: + values = line.strip().replace('?', '0').split() + try: + values = [float(v) for v in values] + + # 合并特征23的取值 + if values[22] == 2 or values[22] == 3: # 特征23(索引22) + labels.append(0) # 死亡 + elif values[22] == 1: + labels.append(1) # 生存 + else: + continue # 无效标签,丢弃 + + # 用0填充缺失值 + values = [0 if v == 0 else v for v in values] # 直接用0填充 + data.append(values[:2] + values[3:23]) # 保留特征1, 2 和特征4-23 + except ValueError: + continue - # 移除类别标签缺失的样本 - data = [row for row in data if not np.isnan(row[-1])] + data = np.array(data) + labels = np.array(labels) - # 使用“0”填充缺失值 - for row in data: - for i in range(len(row)): - if np.isnan(row[i]): - row[i] = 0.0 - - # 合并特征23的值2和3为0 - for row in data: - if row[22] == 2 or row[22] == 3: # 假设特征23是第23个元素 - row[22] = 0 - - # 移除不需要的特征 - data = [row[:2] + row[3:23] + row[28:] for row in data] - - # 分离特征和标签 - X = [row[:-1] for row in data] - y = [row[-1] for row in data] - - scaler = StandardScaler() - X = scaler.fit_transform(X) - - return np.array(X), np.array(y) + return data, labels """ 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**。 @@ -154,10 +131,37 @@ def load_data(filepath): """ if __name__ == "__main__": - X_train, y_train = load_data("./data/horse-colic.data") - X_test, y_test = load_data("./data/horse-colic.test") - - weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=2000) - + # 加载数据集 + X, y = load_data("./data/horse-colic.data") + + # 归一化数据 + X = preprocess_data(X) + + # 使用 train_test_split 打乱并随机抽取数据 + X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.2, random_state=42) + + # K折交叉验证 + k = 5 + kf = KFold(n_splits=k, shuffle=True, random_state=42) + accuracies = [] + + for train_index, val_index in kf.split(X_train): + X_train_kf, X_val_kf = X_train[train_index], X_train[val_index] + y_train_kf, y_val_kf = y_train[train_index], y_train[val_index] + + # 训练逻辑回归模型,设置 batch size + batch_size = 32 + weights = train_logreg(X_train_kf, y_train_kf, learning_rate=0.1, iterations=2000, lambda_reg=0.01, batch_size=batch_size) + + # 验证模型 + val_predictions = [predict_logreg(X_val_kf[i], weights) for i in range(len(X_val_kf))] + accuracy = np.mean(val_predictions == y_val_kf) + accuracies.append(accuracy) + + # 输出交叉验证的准确率和平均准确率 + print(f"K折交叉验证得分: {accuracies}") + print(f"平均准确率: {np.mean(accuracies)}") + + # 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