arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 2212.13232stat.COstat.ME
收藏

带约束主动子空间的条件拟蒙特卡洛方法

Conditional Quasi-Monte Carlo with Constrained Active Subspaces

Sifan Liu

AI总结:

针对现有基于主动子空间的条件拟蒙特卡洛方法中所选预积分方向难处理的问题,提出带约束的主动子空间求解方法,实现高效预积分与降维,在多领域算例中误差更低。

摘要:

条件蒙特卡洛(又称预积分)是在使用蒙特卡洛与拟蒙特卡洛(QMC)方法时,降低方差、改善被积函数正则性的有力工具。选择预积分变量时,需同时考量变量的重要性与条件期望的可处理性。对于高斯分布上的积分,任意变量的线性组合都可作为预积分对象。Liu与Owen(2022)提出基于被积函数的主动子空间分解来选择线性组合,但所选方向的预积分可能难以处理。本研究通过寻找满足约束的主动子空间解决该问题,使预积分可轻松实现。所提算法也为预积分函数的降维提供了一种计算高效的替代方案。该方法被应用于计算金融、密度估计与计算化学领域的算例,结果表明其误差小于现有方法。

英文摘要:

Conditional Monte Carlo or pre-integration is a powerful tool for reducing variance and improving the regularity of integrands when using Monte Carlo and quasi-Monte Carlo (QMC) methods. To select the variable to pre-integrate, one must consider both the variable's importance and the tractability of the conditional expectation. For integrals over a Gaussian distribution, any linear combination of variables can potentially be pre-integrated. Liu and Owen (2022) propose to select the linear combination based on an active subspace decomposition of the integrand. However, pre-integrating the selected direction might be intractable. In this work, we address this issue by finding the active subspace subject to constraints such that pre-integration can be easily carried out. The proposed algorithm also provides a computationally-efficient alternative to dimension reduction for pre-integrated functions. The method is applied to examples from computational finance, density estimation, and computational chemistry, and is shown to achieve smaller errors than previous 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。

↑