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arXiv 1709.05006stat.MLcs.LGstat.APstat.CO
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基于各向异性核的双样本统计量

Two-sample Statistics Based on Anisotropic Kernels

Duke University(杜克大学);University of California, San Diego(加州大学圣地亚哥分校);Yale University(耶鲁大学)

Xiuyuan Cheng, Alexander Cloninger, Ronald R. Coifman

摘要:

本文介绍了一种新的基于核的最大均值离散(MMD)统计量,用于测量有限多个多元样本下两个分布之间的距离。当分布是局部低维时,通过结合局部协方差阵和构造各向异性核,可以使所提出的检验更强大地区分某些替代方案。核矩阵是不对称的;它计算$n$数据点和一组$n_R$参考点之间的亲和度,其中$n_R$可以比$n$小得多。该统计量可看作一类特殊的再生核Hilbert空间MMD,在对核函数的适当假设下,只要$\|p-q\| \sqrt{n} \to \infty $,证明了检验的相合性,并得到了检验功效的有限样本下界.流式细胞术和扩散MRI数据集的应用程序进行了演示,这促使所提出的方法来比较分布。

英文摘要:

The paper introduces a new kernel-based Maximum Mean Discrepancy (MMD) statistic for measuring the distance between two distributions given finitely-many multivariate samples. When the distributions are locally low-dimensional, the proposed test can be made more powerful to distinguish certain alternatives by incorporating local covariance matrices and constructing an anisotropic kernel. The kernel matrix is asymmetric; it computes the affinity between $n$ data points and a set of $n_R$ reference points, where $n_R$ can be drastically smaller than $n$. While the proposed statistic can be viewed as a special class of Reproducing Kernel Hilbert Space MMD, the consistency of the test is proved, under mild assumptions of the kernel, as long as $\|p-q\| \sqrt{n} \to \infty $, and a finite-sample lower bound of the testing power is obtained. Applications to flow cytometry and diffusion MRI datasets are demonstrated, which motivate the proposed approach to compare distributions.

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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