diff --git a/function.py b/function.py index b869523..ca396fa 100644 --- a/function.py +++ b/function.py @@ -1,106 +1,69 @@ -import numpy as np +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" +""" +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 sigmoid(z): + return 1 / (1 + np.exp(-z)) -def train_logreg(X, y, learning_rate=0.01, iterations=1000): - """ - 对率回归训练函数。 - - Args: - - X (numpy array): 特征数据。 - - y (numpy array): 标签数据。 - - learning_rate (float): 学习率,默认为0.01。 - - iterations (int): 迭代次数,默认为1000。 - - Returns: - - weights (numpy array): 训练得到的权重。 - """ - m, n = X.shape - weights = np.zeros(n) - for i in range(iterations): - linear_model = np.dot(X, weights) - y_predicted = sigmoid(linear_model) - gradient = np.dot(X.T, (y_predicted - y)) / m - weights -= learning_rate * gradient - return weights +def train_logreg(X, y, learning_rate=0.01, iterations=1000): + m, n = X.shape + weights = np.zeros(n) + for i in range(iterations): + linear_model = np.dot(X, weights) + y_predicted = sigmoid(linear_model) + gradient = np.dot(X.T, (y_predicted - y)) / m + weights -= learning_rate * gradient + return weights -def predict_logreg(X, weights): - """ - 对率回归预测函数。 - - Args: - - X (numpy array): 输入待分类的样本。 - - weights (numpy array): 训练得到的权重。 - - Returns: - - numpy array: 预测的分类标签。 - """ - linear_model = np.dot(X, weights) - y_predicted = sigmoid(linear_model) - return (y_predicted > 0.5).astype(int) +def predict_logreg(inX, weights): + linear_model = np.dot(inX, weights) + y_predicted = sigmoid(linear_model) + return 1 if y_predicted > 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。 - """ - # 使用 np.genfromtxt 加载数据,并且忽略文件中不能转换为 float 的行 - data = np.genfromtxt(filepath, delimiter=',', dtype=float, filling_values=np.nan) - - # 删除所有包含缺失值的行 - data = data[~np.isnan(data).any(axis=1)] - - # 如果数据仍然是一维的,则将其转换为二维 - if data.ndim == 1: - data = np.array([data]) - - # 确保我们有有效的数据并且是二维的 - if data.shape[0] == 0: # 如果没有数据 - raise ValueError("加载的数据为空,请检查输入文件。") - - # 假设最后一列为标签 - X = data[:, :-1] # 特征 - y = data[:, -1] # 标签 - return X, y +def load_data(filepath): + data = np.genfromtxt(filepath, delimiter=' ', dtype=float) + X = data[:, :-1] + y = data[:, -1] + return X, y -if __name__ == "__main__": - # 加载训练集 - X_train, y_train = load_data("./data/horse-colic.data") +def standardize(X): + mean = X.mean(axis=0) + std = X.std(axis=0) + return (X - mean) / std, mean, std - # 加载测试集 - X_test, y_test = load_data("./data/horse-colic.test") - # 确保训练集和测试集特征数量匹配 - if X_train.shape[1] != X_test.shape[1]: - raise ValueError("训练集和测试集特征数量不匹配!") +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") - # 训练对率回归模型 - weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=1000) + # 标准化特征数据 + X_train, mean, std = standardize(X_train) + X_test = (X_test - mean) / std - # 测试多个数据 - y_pred = predict_logreg(X_test, weights) - - # 输出部分预测结果 - for i in range(min(10, len(y_pred))): # 只输出前10个预测结果 - print(f"预测结果: {y_pred[i]}, 实际结果: {y_test[i]}") \ No newline at end of file + # 训练对率回归模型 + weights = train_logreg(X_train, y_train, learning_rate=0.01, iterations=1000) + + # 测试单个数据 + correct_predictions = 0 + for i in range(X_test.shape[0]): + y_pred = predict_logreg(X_test[i], weights) + if y_pred == y_test[i]: + correct_predictions += 1 + + accuracy = correct_predictions / X_test.shape[0] + print(f"Accuracy: {accuracy:.2f}") + + +if __name__ == "__main__": + main() \ No newline at end of file