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arXiv 2403.09604stat.MEmath.STstat.MLstat.TH
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通过凸优化进行含潜变量的极值图模型建模

Extremal graphical modeling with latent variables via convex optimization

Sebastian Engelke, Armeen Taeb

AI总结:

本文针对含潜变量的极值图模型学习问题,提出可求解的凸规划方法 eglatent,通过将 Hüsler-Reiss 精度矩阵分解为稀疏与低秩分量,一致恢复条件图和潜变量数量,并在合成与真实数据上验证了性能提升。

摘要:

极值图模型编码了多元极值的条件独立结构,并为量化稀有事件风险提供了有力工具。此前从数据中学习这些图的工作主要集中于所有相关变量均可观测的情形。针对流行的 Hüsler-Reiss 模型类,我们提出 \ exttt{eglatent} 方法,这是一个可求解的凸规划,用于在存在潜变量的情况下学习极值图模型。我们的方法将 Hüsler-Reiss 精度矩阵分解为一个稀疏分量和一个低秩分量,其中稀疏分量编码在给定潜变量条件下观测变量之间的图结构,低秩分量编码少数潜变量对观测变量的影响。我们给出了 \ exttt{eglatent} 的有限样本保证,并证明其能够一致地恢复条件图以及潜变量的数量。我们展示了该方法在合成数据和真实数据上改进的性能。

英文摘要:

Extremal graphical models encode the conditional independence structure of multivariate extremes and provide a powerful tool for quantifying the risk of rare events. Prior work on learning these graphs from data has focused on the setting where all relevant variables are observed. For the popular class of Hüsler-Reiss models, we propose the \texttt{eglatent} method, a tractable convex program for learning extremal graphical models in the presence of latent variables. Our approach decomposes the Hüsler-Reiss precision matrix into a sparse component encoding the graphical structure among the observed variables after conditioning on the latent variables, and a low-rank component encoding the effect of a few latent variables on the observed variables. We provide finite-sample guarantees of \texttt{eglatent} and show that it consistently recovers the conditional graph as well as the number of latent variables. We highlight the improved performances of our approach on synthetic and real 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。

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