diff --git a/function.py b/function.py index 2ca8b09..36ba124 100644 --- a/function.py +++ b/function.py @@ -29,33 +29,21 @@ def load_data(filepath): - X (numpy array): 包含非线性特征的特征数据 - y (numpy array): 标签数据 """ - # 读取数据,指定分隔符为空格,缺失值符号为 '?' data = np.genfromtxt(filepath, delimiter=" ", dtype=str) - - # 将 '?' 替换为 np.nan 并转换为浮点数 data[data == '?'] = np.nan data = data.astype(float) - - # 对每一列的缺失值使用列的均值填充 col_means = np.nanmean(data, axis=0) inds = np.where(np.isnan(data)) data[inds] = np.take(col_means, inds[1]) - - # 分离特征和标签 X = data[:, :-1] y = data[:, -1] - - # 生成非线性特征 (平方和对数) square_features = X ** 2 - log_features = np.log1p(X) # 使用 log1p 避免 log(0) - - # 将非线性特征添加到原特征集 + log_features = np.log1p(X) X = np.hstack([X, square_features, log_features]) - return X, y # 对率回归训练函数 -def train_logreg(X, y, learning_rate=0.01, num_iterations=1000, regularization_strength=0): +def train_logreg(X, y, initial_learning_rate=0.1, num_iterations=2000, regularization_strength=0.1): """ 对率回归训练函数。 @@ -69,79 +57,50 @@ def train_logreg(X, y, learning_rate=0.01, num_iterations=1000, regularization_s Returns: - weights (numpy array): 训练得到的权重。 """ + m, n = X.shape - weights = np.zeros(n) - for _ in range(num_iterations): + weights = np.random.randn(n) * 0.01 # 随机初始化权重 + learning_rate = initial_learning_rate + for i in range(num_iterations): predictions = 1 / (1 + np.exp(-np.dot(X, weights))) gradient = (1 / m) * np.dot(X.T, (predictions - y)) + regularization_strength * weights weights -= learning_rate * gradient + if i % 100 == 0: # 每100次迭代降低学习率 + learning_rate *= 0.9 return weights # 决策树训练函数 def train_decision_tree(X, y): - """ - 训练简单的决策树模型。 - - Args: - - X (numpy array): 特征数据 - - y (numpy array): 标签数据 - - Returns: - - clf (DecisionTreeClassifier): 训练好的决策树模型 - """ clf = DecisionTreeClassifier(max_depth=5, random_state=42) clf.fit(X, y) return clf # 对率回归预测函数 def predict_logreg(inX, weights): - """ - 对率回归预测函数。 - - 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。 - """ probability = 1 / (1 + np.exp(-np.dot(inX, weights))) - return 1 if probability >= 0.4 else 0 + return 1 if probability >= 0.5 else 0 + # 融合预测函数 -def predict_fusion(inX, weights, clf): - """ - 融合对率回归和决策树的预测结果。 - - Args: - - inX (numpy array): 输入待分类的样本。 - - weights (numpy array): 对率回归的权重。 - - clf (DecisionTreeClassifier): 训练好的决策树模型。 - - Returns: - - int: 最终预测的分类标签。 - """ - # 对率回归预测 - prediction_logreg = predict_logreg(inX, weights) - - # 决策树预测 - prediction_tree = clf.predict(inX.reshape(1, -1))[0] - - # 融合投票 - final_prediction = 1 if (prediction_logreg + prediction_tree) >= 1 else 0 - return final_prediction +def predict_fusion(inX, weights, clf, alpha=0.6): + prob_logreg = 1 / (1 + np.exp(-np.dot(inX, weights))) + prob_tree = clf.predict_proba(inX.reshape(1, -1))[0, 1] + final_prob = alpha * prob_logreg + (1 - alpha) * prob_tree + return 1 if final_prob >= 0.5 else 0 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") - - # 加载测试集 X_test, y_test = load_data("./data/horse-colic.test") # 训练对率回归模型 - weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=1000) + weights = train_logreg(X_train, y_train, initial_learning_rate=0.1, num_iterations=2000) + + # 训练决策树模型 + clf = train_decision_tree(X_train, y_train) # 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]}") + y_pred_logreg = predict_logreg(X_test[11], weights) + y_pred_fusion = predict_fusion(X_test[11], weights, clf) + + print(f"对率回归预测结果: {y_pred_logreg}, 实际结果: {y_test[11]}") + print(f"融合预测结果: {y_pred_fusion}, 实际结果: {y_test[11]}") \ No newline at end of file