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Wenkai Xu

12 accepted papers

2022

AgraSSt: Approximate Graph Stein Statistics for Interpretable Assessment of Implicit Graph Generators

NeurIPS 2022accept

We propose and analyse a novel statistical procedure, coined AgraSSt, to assess the quality of graph generators which may not be available in explicit forms. In particular, AgraSSt can be used to determine whether a learned graph generating process is capable of generating graphs which resemble a gi…

2022

Standardisation-function Kernel Stein Discrepancy: A Unifying View on Kernel Stein Discrepancy Tests for Goodness-of-fit

AISTATS 2022poster

Non-parametric goodness-of-fit testing procedures based on kernel Stein discrepancies (KSD) are promising approaches to validate general unnormalised distributions in various scenarios. Existing works focused on studying kernel choices to boost test performances. However, the choices of (non-unique)…

Cited by 8SourcePDFScholar
2021

Meta Two-Sample Testing: Learning Kernels for Testing with Limited Data

NeurIPS 2021poster

Modern kernel-based two-sample tests have shown great success in distinguishing complex, high-dimensional distributions by learning appropriate kernels (or, as a special case, classifiers). Previous work, however, has assumed that many samples are observed from both of the distributions being distin…

2020

Kernelized Stein Discrepancy Tests of Goodness-of-fit for Time-to-Event Data

ICML 2020poster

Survival Analysis and Reliability Theory are concerned with the analysis of time-to-event data, in which observations correspond to waiting times until an event of interest such as death from a particular disease or failure of a component in a mechanical system. This type of data is unique due to th…

Cited by 19SourcePDFScholar
2020

Learning Deep Kernels for Non-Parametric Two-Sample Tests

ICML 2020poster

We propose a class of kernel-based two-sample tests, which aim to determine whether two sets of samples are drawn from the same distribution. Our tests are constructed from kernels parameterized by deep neural nets, trained to maximize test power. These tests adapt to variations in distribution smoo…

2017

A Linear-Time Kernel Goodness-of-Fit Test

NeurIPS 2017oral

We propose a novel adaptive test of goodness-of-fit, with computational cost linear in the number of samples. We learn the test features that best indicate the differences between observed samples and a reference model, by minimizing the false negative rate. These features are constructed via Stein'…