arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2202.11599math.OC
收藏

NysADMM:基于低秩近似的快速复合凸优化

NysADMM: faster composite convex optimization via low-rank approximation

Shipu Zhao, Zachary Frangella, Madeleine Udell

摘要:

本文提出了一个可扩展的新算法,称为NysADMM,以最小化一个光滑的凸损失函数与凸正则化。NysADMM通过从随机低秩Nyström近似构造ADMM子问题的预条件子来加速不精确乘子交替方向法(ADMM)。NysADMM有很强的理论保证:当Nyström近似的秩是子问题正则化Gram矩阵的有效维数时,它可以在恒定的迭代次数内解决ADMM子问题。在实践中,排名小于的有效维度可以成功,所以NysADMM使用自适应策略来选择享有类似保证的排名。在真实世界数据集上的数值实验表明,NysADMM可以解决重要的应用程序,如套索,逻辑斯谛回归和支持向量机,在一半的时间(或更少)所需的标准求解器。NysADMM击败标准求解器的问题的广度是一个惊喜:它表明ADMM是一个占主导地位的范式,用于在广泛的统计学习问题中进行数值优化,这些问题通常是用定制方法解决的。

英文摘要:

This paper develops a scalable new algorithm, called NysADMM, to minimize a smooth convex loss function with a convex regularizer. NysADMM accelerates the inexact Alternating Direction Method of Multipliers (ADMM) by constructing a preconditioner for the ADMM subproblem from a randomized low-rank Nyström approximation. NysADMM comes with strong theoretical guarantees: it solves the ADMM subproblem in a constant number of iterations when the rank of the Nyström approximation is the effective dimension of the subproblem regularized Gram matrix. In practice, ranks much smaller than the effective dimension can succeed, so NysADMM uses an adaptive strategy to choose the rank that enjoys analogous guarantees. Numerical experiments on real-world datasets demonstrate that NysADMM can solve important applications, such as the lasso, logistic regression, and support vector machines, in half the time (or less) required by standard solvers. The breadth of problems on which NysADMM beats standard solvers is a surprise: it suggests that ADMM is a dominant paradigm for numerical optimization across a wide range of statistical learning problems that are usually solved with bespoke methods.

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。

↑