A Fourier representation of kernel Stein discrepancy with application to
Goodness-of-Fit tests for measures on infinite dimensional Hilbert spaces
- URL: http://arxiv.org/abs/2206.04552v3
- Date: Sun, 20 Aug 2023 14:13:41 GMT
- Title: A Fourier representation of kernel Stein discrepancy with application to
Goodness-of-Fit tests for measures on infinite dimensional Hilbert spaces
- Authors: George Wynne, Miko{\l}aj Kasprzak, Andrew B. Duncan
- Abstract summary: Kernel Stein discrepancy (KSD) is a kernel-based measure of discrepancy between probability measures.
We provide the first analysis of KSD in the generality of data lying in a separable Hilbert space.
This allows us to prove that KSD can separate measures and thus is valid to use in practice.
- Score: 6.437931786032493
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Kernel Stein discrepancy (KSD) is a widely used kernel-based measure of
discrepancy between probability measures. It is often employed in the scenario
where a user has a collection of samples from a candidate probability measure
and wishes to compare them against a specified target probability measure. KSD
has been employed in a range of settings including goodness-of-fit testing,
parametric inference, MCMC output assessment and generative modelling. However,
so far the method has been restricted to finite-dimensional data. We provide
the first analysis of KSD in the generality of data lying in a separable
Hilbert space, for example functional data. The main result is a novel Fourier
representation of KSD obtained by combining the theory of measure equations
with kernel methods. This allows us to prove that KSD can separate measures and
thus is valid to use in practice. Additionally, our results improve the
interpretability of KSD by decoupling the effect of the kernel and Stein
operator. We demonstrate the efficacy of the proposed methodology by performing
goodness-of-fit tests for various Gaussian and non-Gaussian functional models
in a number of synthetic data experiments.
Related papers
- Nyström Kernel Stein Discrepancy [4.551160285910023]
We propose a Nystr"om-based KSD acceleration -- with runtime $mathcal Oleft(mn+m3right)$ for $n$ samples and $mll n$ Nystr"om points.
We show its $sqrtn$-consistency with a classical sub-Gaussian assumption, and demonstrate its applicability for goodness-of-fit testing on a suite of benchmarks.
arXiv Detail & Related papers (2024-06-12T16:50:12Z) - Minimax Optimal Goodness-of-Fit Testing with Kernel Stein Discrepancy [13.429541377715298]
We explore the minimax optimality of goodness-of-fit tests on general domains using the kernelized Stein discrepancy (KSD)
The KSD framework offers a flexible approach for goodness-of-fit testing, avoiding strong distributional assumptions.
We introduce an adaptive test capable of achieving minimax optimality up to a logarithmic factor by adapting to unknown parameters.
arXiv Detail & Related papers (2024-04-12T07:06:12Z) - Score-based Diffusion Models in Function Space [140.792362459734]
Diffusion models have recently emerged as a powerful framework for generative modeling.
We introduce a mathematically rigorous framework called Denoising Diffusion Operators (DDOs) for training diffusion models in function space.
We show that the corresponding discretized algorithm generates accurate samples at a fixed cost independent of the data resolution.
arXiv Detail & Related papers (2023-02-14T23:50:53Z) - Machine-Learned Exclusion Limits without Binning [0.0]
We extend the Machine-Learned Likelihoods (MLL) method by including Kernel Density Estimators (KDE) to extract one-dimensional signal and background probability density functions.
We apply the method to two cases of interest at the LHC: a search for exotic Higgs bosons, and a $Z'$ boson decaying into lepton pairs.
arXiv Detail & Related papers (2022-11-09T11:04:50Z) - A kernel Stein test of goodness of fit for sequential models [19.8408003104988]
The proposed measure is an instance of the kernel Stein discrepancy (KSD), which has been used to construct goodness-of-fit tests for unnormalized densities.
We extend the KSD to the variable-dimension setting by identifying appropriate Stein operators, and propose a novel KSD goodness-of-fit test.
Our test is shown to perform well in practice on discrete sequential data benchmarks.
arXiv Detail & Related papers (2022-10-19T17:30:15Z) - FaDIn: Fast Discretized Inference for Hawkes Processes with General
Parametric Kernels [82.53569355337586]
This work offers an efficient solution to temporal point processes inference using general parametric kernels with finite support.
The method's effectiveness is evaluated by modeling the occurrence of stimuli-induced patterns from brain signals recorded with magnetoencephalography (MEG)
Results show that the proposed approach leads to an improved estimation of pattern latency than the state-of-the-art.
arXiv Detail & Related papers (2022-10-10T12:35:02Z) - Targeted Separation and Convergence with Kernel Discrepancies [61.973643031360254]
kernel-based discrepancy measures are required to (i) separate a target P from other probability measures or (ii) control weak convergence to P.
In this article we derive new sufficient and necessary conditions to ensure (i) and (ii)
For MMDs on separable metric spaces, we characterize those kernels that separate Bochner embeddable measures and introduce simple conditions for separating all measures with unbounded kernels.
arXiv Detail & Related papers (2022-09-26T16:41:16Z) - Experimental Design for Linear Functionals in Reproducing Kernel Hilbert
Spaces [102.08678737900541]
We provide algorithms for constructing bias-aware designs for linear functionals.
We derive non-asymptotic confidence sets for fixed and adaptive designs under sub-Gaussian noise.
arXiv Detail & Related papers (2022-05-26T20:56:25Z) - Measuring dissimilarity with diffeomorphism invariance [94.02751799024684]
We introduce DID, a pairwise dissimilarity measure applicable to a wide range of data spaces.
We prove that DID enjoys properties which make it relevant for theoretical study and practical use.
arXiv Detail & Related papers (2022-02-11T13:51:30Z) - KSD Aggregated Goodness-of-fit Test [38.45086141837479]
We introduce a strategy to construct a test, called KSDAgg, which aggregates multiple tests with different kernels.
We provide non-asymptotic guarantees on the power of KSDAgg.
We find that KSDAgg outperforms other state-of-the-art adaptive KSD-based goodness-of-fit testing procedures.
arXiv Detail & Related papers (2022-02-02T00:33:09Z) - A Note on Optimizing Distributions using Kernel Mean Embeddings [94.96262888797257]
Kernel mean embeddings represent probability measures by their infinite-dimensional mean embeddings in a reproducing kernel Hilbert space.
We show that when the kernel is characteristic, distributions with a kernel sum-of-squares density are dense.
We provide algorithms to optimize such distributions in the finite-sample setting.
arXiv Detail & Related papers (2021-06-18T08:33:45Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.