arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2408.04607stat.MLcond-mat.dis-nncs.LG
收藏

带相关样本的岭回归中的风险与交叉验证

Risk and cross validation in ridge regression with correlated samples

Department of Physics, Harvard University(哈佛大学物理系);Center for Brain Science, Harvard University(哈佛大学脑科学中心);Society of Fellows, Harvard University(哈佛大学 fellows 会);John A. Paulson School of Engineering and Applied Sciences, Harvard University(哈佛大学约翰·A·保罗森工程与应用科学学院);Kempner Institute for the Study of Natural and Artificial Intelligence, Harvard University(哈佛大学自然与人工智能研究学院)

Alexander Atanasov, Jacob A. Zavatone-Veth, Cengiz Pehlevan

AI总结:

利用随机矩阵理论和自由概率,研究了数据点具有任意相关性时岭回归的渐近风险,并提出了修正的广义交叉验证估计器CorrGCV,同时扩展到测试点与训练集相关的情况。

摘要:

近年来,我们对高维岭回归的理解取得了实质性进展,但现有理论假设训练样本是独立的。通过利用随机矩阵理论和自由概率的技术,我们为数据点具有任意相关性时岭回归的样本内和样本外风险提供了精确的渐近结果。我们证明,在这种情况下,广义交叉验证估计器(GCV)无法正确预测样本外风险。然而,当噪声残差与数据点具有相同相关性时,可以修改GCV以产生一个在高维极限下集中的高效可计算无偏估计器,我们称之为CorrGCV。我们进一步将渐近分析扩展到测试点与训练集具有非平凡相关性的情况,这是时间序列预测中经常遇到的情况。假设已知时间序列的相关结构,这再次产生了GCV估计器的扩展,并精确刻画了此类测试点对长期风险产生过于乐观预测的程度。我们在各种高维数据上验证了理论的预测。

英文摘要:

Recent years have seen substantial advances in our understanding of high-dimensional ridge regression, but existing theories assume that training examples are independent. By leveraging techniques from random matrix theory and free probability, we provide sharp asymptotics for the in- and out-of-sample risks of ridge regression when the data points have arbitrary correlations. We demonstrate that in this setting, the generalized cross validation estimator (GCV) fails to correctly predict the out-of-sample risk. However, in the case where the noise residuals have the same correlations as the data points, one can modify the GCV to yield an efficiently-computable unbiased estimator that concentrates in the high-dimensional limit, which we dub CorrGCV. We further extend our asymptotic analysis to the case where the test point has nontrivial correlations with the training set, a setting often encountered in time series forecasting. Assuming knowledge of the correlation structure of the time series, this again yields an extension of the GCV estimator, and sharply characterizes the degree to which such test points yield an overly optimistic prediction of long-time risk. We validate the predictions of our theory across a variety of high dimensional data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑