generated from LufsX/Experiment-LogReg
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+24
-52
@@ -17,74 +17,34 @@ from sklearn.preprocessing import StandardScaler
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- numpy: 2.1.1
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"""
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# 请在这里填写学号和姓名,不填写即成绩无效。
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id = "202210423130"
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name = "董秋"
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def sigmoid(z):
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"""Sigmoid 激活函数。"""
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return 1 / (1 + np.exp(-z))
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# 逻辑回归训练函数
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def train_logreg(X, y, learning_rate=0.01, iterations=1000, lambda_reg=0.01):
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"""
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对率回归训练函数。
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Args:
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- X (numpy array): 特征数据。
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- y (numpy array): 标签数据。
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- learning_rate (float): 学习率。
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- iterations (int): 迭代次数。
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- lambda_reg (float): L2正则化参数。
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Returns:
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- numpy array: 训练得到的权重。
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"""
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m, n = X.shape
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weights = np.random.randn(n) * 0.01 # 随机初始化权重
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for _ in range(iterations):
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for i in range(iterations):
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z = np.dot(X, weights)
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predictions = sigmoid(z)
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gradient = np.dot(X.T, (predictions - y)) / m
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# L2正则化
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gradient += (lambda_reg / m) * weights
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# 更新权重
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weights -= learning_rate * gradient
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predictions = 1 / (1 + np.exp(-z)) # Sigmoid 激活函数
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gradient = np.dot(X.T, (predictions - y)) / m + (lambda_reg / m) * weights # L2 正则化
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weights -= learning_rate * gradient # 更新权重
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return weights
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# 逻辑回归预测函数
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def predict_logreg(inX, weights):
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"""
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对率回归预测函数。
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Args:
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- inX (numpy array): 输入待分类的样本。
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- weights (numpy array): 训练得到的权重。
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Returns:
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- int: 预测的分类标签。
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"""
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z = np.dot(inX, weights)
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prediction_prob = sigmoid(z)
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prediction_prob = 1 / (1 + np.exp(-z)) # Sigmoid 激活函数
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return 1 if prediction_prob >= 0.5 else 0
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# 从文件中加载数据
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def load_data(filepath):
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"""
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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**。
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Args:
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- directory (str): 数据文件路径。
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Returns:
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- np.array: 特征数据。
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- np.array: 标签数据。
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"""
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data = []
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labels = []
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@@ -94,6 +54,13 @@ def load_data(filepath):
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try:
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values = [float(v) for v in values]
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# 跳过第3行(索引为2)和24-28行(索引为23-27)
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if len(data) in [2, 23, 24, 25, 26, 27]:
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continue
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# 用0填充缺失值
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values = [0 if v == 0 else v for v in values] # 用0填充
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# 合并特征23的取值
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if values[22] == 2 or values[22] == 3: # 特征23(索引22)
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labels.append(0) # 死亡
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@@ -102,13 +69,18 @@ def load_data(filepath):
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else:
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continue # 无效标签,丢弃
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# 用0填充缺失值
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values = [0 if v == 0 else v for v in values] # 直接用0填充
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data.append(values[:2] + values[3:23]) # 保留特征1, 2 和特征4-23
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except ValueError:
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continue
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return np.array(data), np.array(labels)
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data = np.array(data)
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labels = np.array(labels)
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# 数据归一化
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scaler = StandardScaler()
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data = scaler.fit_transform(data)
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return data, labels
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if __name__ == "__main__":
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