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最小最大固定设计线性回归

Minimax Fixed-Design Linear Regression
课程网址: https://videolectures.net/videos/colt2015_malek_linear_regression  
主讲教师: Alan Malek
开课单位: 信息不详。欢迎您在右侧留言补充。
开课时间: 2025-02-04
课程语种: 英语
中文简介:
我们考虑一个线性回归博弈,其中协变量是事先已知的:在每一轮中,学习器预测一个实值,对手显示一个标签,学习器产生平方误差损失。其目的是将线性预测的遗憾最小化。对于对手标签上的各种约束,我们表明极大极小最优策略是线性的,其参数选择让人想起普通的最小二乘(并且易于计算)。预测依赖于所有协变量,过去的和未来的,未来的协变量有一个特定的权重,对应于它们在极大极小后悔中所扮演的角色。我们研究了两类标签序列:盒约束(在协变量相容条件下)和从分析中自然产生的加权2范数约束。该策略是自适应的,因为它不需要了解约束集。我们得到了这些博弈的极大极小遗憾的显式表达式。对于一致框约束的情况,我们表明,对于最坏情况的协变量序列,遗憾是$O(d\log T)$,不依赖于协变量的缩放。
课程简介: We consider a linear regression game in which the covariates are known in advance: at each round, the learner predicts a real-value, the adversary reveals a label, and the learner incurs a squared error loss. The aim is to minimize the regret with respect to linear predictions. For a variety of constraints on the adversary's labels, we show that the minimax optimal strategy is linear, with a parameter choice that is reminiscent of ordinary least squares (and as easy to compute). The predictions depend on all covariates, past and future, with a particular weighting assigned to future covariates corresponding to the role that they play in the minimax regret. We study two families of label sequences: box constraints (under a covariate compatibility condition), and a weighted 2-norm constraint that emerges naturally from the analysis. The strategy is adaptive in the sense that it requires no knowledge of the constraint set. We obtain an explicit expression for the minimax regret for these games. For the case of uniform box constraints, we show that, with worst case covariate sequences, the regret is $O(d\log T)$, with no dependence on the scaling of the covariates.
关 键 词: 线性回归博弈; 协变量:线性预测
课程来源: 视频讲座网
数据采集: 2025-03-28:zsp
最后编审: 2025-03-28:zsp
阅读次数: 4