diff --git a/function.py b/function.py index fff94f4..f189af5 100644 --- a/function.py +++ b/function.py @@ -1,30 +1,61 @@ import numpy as np +""" +请在这里填写学号和姓名,不填写即成绩无效。 +""" id = "202210423224" name = "吴杨洋" + def sigmoid(z): + """ + Sigmoid 激活函数。 + """ return 1 / (1 + np.exp(-z)) + def train_logreg(X, y, numIter=1000, learning_rate=0.01, lambda_reg=0.01): m, n = X.shape weights = np.zeros(n) for j in range(numIter): - z = np.dot(X, weights) - h = sigmoid(z) - error = y - h - gradient = np.dot(X.T, error) / m - reg_term = lambda_reg * weights - gradient += reg_term / m - weights -= learning_rate * gradient + 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): + """ + 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。 + """ z = np.dot(inX, weights) prob = sigmoid(z) return 1 if prob >= 0.5 else 0 + def load_data(filepath): + """ + 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。 + + Args: + - filepath (str): 数据文件路径。 + + Returns: + - X (np.array): 特征数据。 + - y (np.array): 标签数据。 + """ file = open(filepath) fr = file.readlines() data_list = [] @@ -47,26 +78,34 @@ def load_data(filepath): data_number = len(y) y_train = np.array([1 if y[j] == '2' or y[j] == '3' else 0 for j in range(data_number)]) X = np.array(data_list) - X = np.insert(X, 0, 1, axis=1) # 添加偏置项,应该在第一列添加 - return X, y_train + X_train = np.insert(X, 0, 1, axis=1) # 添加偏置项 + return X_train, y_train + def standardize(X): mean = X.mean(axis=0) std = X.std(axis=0) return (X - mean) / std, mean, std + def main(): + # 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") + # 标准化特征数据 X_train, mean, std = standardize(X_train) X_test = (X_test - mean) / std + # 训练对率回归模型 weights = train_logreg(X_train, y_train, numIter=1000, learning_rate=0.01, lambda_reg=0.1) + # 测试单个数据 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() \ No newline at end of file