generated from LufsX/Experiment-LogReg
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+7
-23
@@ -36,14 +36,9 @@ def load_data(filepath):
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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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# 使用np.genfromtxt加载数据,它可以自动处理缺失值
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data = np.genfromtxt(filepath, delimiter=',', skip_header=1, filling_values=np.nan)
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# 分离特征和标签
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# 确保data不是一维数组
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if data.ndim == 1:
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data = data.reshape(1, -1) # 将其转换为二维数组,如果它是一维的
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X = data[:, :-1]
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y = data[:, -1].flatten() # 确保y是一维数组
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@@ -53,7 +48,7 @@ def load_data(filepath):
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y = y[mask]
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return X, y
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def sigmoid(z):
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"""
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Sigmoid函数。
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@@ -84,11 +79,15 @@ def train_logreg(X, y, learning_rate=0.01, iterations=1000):
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# 初始化权重
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weights = np.zeros(X.shape[1])
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# 检查y是否为空
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if len(y) == 0:
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raise ValueError("标签数组y为空")
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for _ in range(iterations):
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# 计算预测值
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predictions = sigmoid(np.dot(X, weights))
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# 计算梯度
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gradient = np.dot(X.T, (predictions - y)) / len(y)
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gradient = np.dot(X.T, (predictions - y)) / max(len(y), 1) # 防止除以零
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# 更新权重
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weights -= learning_rate * gradient
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@@ -107,19 +106,4 @@ def predict_logreg(inX, weights):
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"""
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inX = np.c_[1, inX] # 添加截距项
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prob = sigmoid(np.dot(inX, weights))
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return 1 if prob > 0.5 else 0
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# 移除以下测试代码,仅在本地测试时使用
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# if __name__ == "__main__":
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# # 加载训练集
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# X_train, y_train = load_data("./data/horse-colic.data")
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#
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# # 加载测试集
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# X_test, y_test = load_data("./data/horse-colic.test")
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#
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# # 训练对率回归模型
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# weights = train_logreg(X_train, y_train)
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#
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# # 测试单个数据
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# y_pred = predict_logreg(X_test[11], weights)
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# print(f"预测结果: {y_pred}, 实际结果: {int(y_test[11])}")
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return 1 if prob > 0.5 else 0
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