diff --git a/function.py b/function.py index 409b1ac..8145e44 100644 --- a/function.py +++ b/function.py @@ -1,6 +1,5 @@ # function.py import numpy as np - """ 实验说明: - 自行编写实现数据加载与预测病马死亡的对率回归算法。 @@ -21,12 +20,12 @@ import numpy as np """ 请在这里填写学号和姓名,不填写即成绩无效。 """ -id = "202210423xxx" -name = "test_name" +id = "202210423109" +name = "孔祥芷" # 这里写自己的代码实现 -def train_logreg(X, y, other_params="你自己设置一些其它参数"): +def train_logreg(X, y, numIter=1000, learning_rate=0.06, batch_size=128): """ 对率回归训练函数。 @@ -38,6 +37,27 @@ def train_logreg(X, y, other_params="你自己设置一些其它参数"): Returns: - numpy array: 训练得到的权重。 """ + m, n = X.shape # m: 样本数, n: 特征数 + weights = np.zeros(n) # 参数初始化 + + for j in range(numIter): + # 随机打乱样本顺序 + dataIndex = np.random.permutation(m) + for i in range(0, m, batch_size): + end = min(i + batch_size, m) + # 批量梯度下降 + batch_X = X[dataIndex[i:end]] + batch_y = y[dataIndex[i:end]] + + # 计算梯度 + z = np.dot(batch_X, weights) + h = 1 / (1 + np.exp(-z)) # 计算h + error = batch_y - h # 计算误差 + gradient = np.dot(batch_X.T, error) / len(batch_y) # 计算梯度 + weights += learning_rate * gradient # 更新权重 + + return weights + def predict_logreg(inX, weights): @@ -51,6 +71,10 @@ def predict_logreg(inX, weights): Returns: - int: 预测的分类标签。 """ + z = np.dot(inX, weights) # 线性组合 + prob = 1 / (1 + np.exp(-z)) # 计算概率 + return 1 if prob >= 0.5 else 0 # 返回分类标签 + # 这里也写自己的代码实现 @@ -66,8 +90,36 @@ def load_data(filepath): - np.array: 标签数据。 """ + file = open(filepath) + fr = file.readlines() + data_list = [] + y = [] + for data in fr: + data = data.strip() + data = data.split(' ') + data_25 = data[24] + y.append(data[22]) + del data[-1] + del data[26] + del data[25] + del data[24] + del data[22] + del data[2] + for i in data_25: + data.append(i) + data = [0 if data_elem == '?' else float(data_elem) for data_elem in data] + data_list.append(data) + 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_train = np.insert(X, 0, 1, axis=1) + return X_train, y_train + + + 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") @@ -80,4 +132,14 @@ if __name__ == "__main__": # 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]}") + print(f"预测结果: {y_pred}, 实际结果: {y_test[11]}")''' + 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, numIter=1000, learning_rate=0.01) + error=0 + for i in range(len(y_test)): + y_pred = predict_logreg(X_test[i], weights) + if y_pred != y_test[i]: + error+=1 + print(f"预测结果: {y_pred}, 实际结果: {y_test[i]}") + print((len(y_test)-error)/len(y_test))