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arXiv 2104.07084stat.MEcs.LGmath.OCstat.COstat.ML
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离散优化的分组变量选择:计算与统计观点

Grouped Variable Selection with Discrete Optimization: Computational and Statistical Perspectives

Google Research(谷歌研究院);Massachusetts Institute of Technology(麻省理工学院);University of Sydney(悉尼大学)

Hussein Hazimeh, Rahul Mazumder, Peter Radchenko

摘要:

我们提出了一个新的算法框架,分组变量选择是基于离散数学优化。虽然有几个有吸引力的方法的基础上凸松弛和非凸矩阵,我们专注于最佳解决方案的$\ell_0$正规化的制定,一个问题,是相对未探索的,由于计算的挑战。我们的方法涵盖了高维线性回归和非参数稀疏加性建模光滑组件。我们的算法框架包括近似算法和精确算法。近似算法是基于坐标下降和局部搜索,与流行的稀疏学习算法的运行时间。我们的精确算法是基于一个独立的分支定界(BnB)框架,它可以解决相关的混合整数规划(MIP)问题,以证明最优性。通过利用问题结构,我们的自定义BnB算法可以在几分钟到几小时内解决具有$5 \times 10^6$特征和$10^3$观测的最优性问题实例--比目前使用最先进的商业MIP求解器所能解决的$1000$大$1000$倍。我们还探讨了基于$\ell_0$的估计量的统计特性。我们从理论和经验上证明,我们提出的估计量在各种制度的统计性能方面比流行的组稀疏估计量有优势。我们提供了一个开源的实现我们提出的框架。

英文摘要:

We present a new algorithmic framework for grouped variable selection that is based on discrete mathematical optimization. While there exist several appealing approaches based on convex relaxations and nonconvex heuristics, we focus on optimal solutions for the $\ell_0$-regularized formulation, a problem that is relatively unexplored due to computational challenges. Our methodology covers both high-dimensional linear regression and nonparametric sparse additive modeling with smooth components. Our algorithmic framework consists of approximate and exact algorithms. The approximate algorithms are based on coordinate descent and local search, with runtimes comparable to popular sparse learning algorithms. Our exact algorithm is based on a standalone branch-and-bound (BnB) framework, which can solve the associated mixed integer programming (MIP) problem to certified optimality. By exploiting the problem structure, our custom BnB algorithm can solve to optimality problem instances with $5 \times 10^6$ features and $10^3$ observations in minutes to hours -- over $1000$ times larger than what is currently possible using state-of-the-art commercial MIP solvers. We also explore statistical properties of the $\ell_0$-based estimators. We demonstrate, theoretically and empirically, that our proposed estimators have an edge over popular group-sparse estimators in terms of statistical performance in various regimes. We provide an open-source implementation of our proposed framework.

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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