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arXiv 1801.00682math.NAcs.NA
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基于概率子空间的界限及其在主动子空间中的应用

A Probabilistic Subspace Bound with Application to Active Subspaces

North Carolina State University(北卡罗来纳州立大学)

John T. Holodnak, Ilse C. F. Ipsen, Ralph C. Smith

AI总结:

本文提出基于随机化的子空间界限,用于主动子空间参数选择,提供非渐近且明确的采样数量界,提高计算效率。

摘要:

给定一个实对称半正定矩阵E和一个由n个独立矩阵值随机变量组成的近似S,本文给出了由于随机化导致S相对误差的界限。这些界限不依赖于矩阵维度,仅取决于E的数值秩(内在维度)。我们的方法类似于随机特征用于核矩阵的低秩近似,但我们的精度度量更为严格。在基于主动子空间的参数选择背景下,其中S通过蒙特卡洛采样计算,本文提出一个采样数量的界,使得以高概率主导子空间E和S之间的角度小于用户指定的容差。这比现有工作有显著改进,因为它是一个非渐近且完全明确的采样数量n的界,并允许用户调节成功概率。此外,它表明在存在许多参数的情况下,蒙特卡洛采样可以高效,只要底层函数f足够光滑。

英文摘要:

Given a real symmetric positive semi-definite matrix E, and an approximation S that is a sum of n independent matrix-valued random variables, we present bounds on the relative error in S due to randomization. The bounds do not depend on the matrix dimensions but only on the numerical rank (intrinsic dimension) of E. Our approach resembles the low-rank approximation of kernel matrices from random features, but our accuracy measures are more stringent. In the context of parameter selection based on active subspaces, where S is computed via Monte Carlo sampling, we present a bound on the number of samples so that with high probability the angle between the dominant subspaces of E and S is less than a user-specified tolerance. This is a substantial improvement over existing work, as it is a non-asymptotic and fully explicit bound on the sampling amount n, and it allows the user to tune the success probability. It also suggests that Monte Carlo sampling can be efficient in the presence of many parameters, as long as the underlying function f is sufficiently smooth.

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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