Kernel Two-Sample Testing via Directional Components Analysis

Fuente: arXiv
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Autori principali: Cui, Rui, Li, Yuhao, Song, Xiaojun
Natura: Preprint
Pubblicazione: 2025
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author Cui, Rui
Li, Yuhao
Song, Xiaojun
author_facet Cui, Rui
Li, Yuhao
Song, Xiaojun
contents We propose a novel kernel-based two-sample test that leverages the spectral decomposition of the maximum mean discrepancy (MMD) statistic to identify and utilize well-estimated directional components in reproducing kernel Hilbert space (RKHS). Our approach is motivated by the observation that the estimation quality of these components varies significantly, with leading eigen-directions being more reliably estimated in finite samples. By focusing on these directions and aggregating information across multiple kernels, the proposed test achieves higher power and improved robustness, especially in high-dimensional and unbalanced sample settings. We further develop a computationally efficient multiplier bootstrap procedure for approximating critical values, which is theoretically justified and significantly faster than permutation-based alternatives. Extensive simulations and empirical studies on microarray datasets demonstrate that our method maintains the nominal Type I error rate and delivers superior power compared to other existing MMD-based tests.
format Preprint
id arxiv_https___arxiv_org_abs_2508_08564
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Kernel Two-Sample Testing via Directional Components Analysis
Cui, Rui
Li, Yuhao
Song, Xiaojun
Methodology
Statistics Theory
Machine Learning
We propose a novel kernel-based two-sample test that leverages the spectral decomposition of the maximum mean discrepancy (MMD) statistic to identify and utilize well-estimated directional components in reproducing kernel Hilbert space (RKHS). Our approach is motivated by the observation that the estimation quality of these components varies significantly, with leading eigen-directions being more reliably estimated in finite samples. By focusing on these directions and aggregating information across multiple kernels, the proposed test achieves higher power and improved robustness, especially in high-dimensional and unbalanced sample settings. We further develop a computationally efficient multiplier bootstrap procedure for approximating critical values, which is theoretically justified and significantly faster than permutation-based alternatives. Extensive simulations and empirical studies on microarray datasets demonstrate that our method maintains the nominal Type I error rate and delivers superior power compared to other existing MMD-based tests.
title Kernel Two-Sample Testing via Directional Components Analysis
topic Methodology
Statistics Theory
Machine Learning
url https://arxiv.org/abs/2508.08564