A Deterministic Sampling Method via Maximum Mean Discrepancy Flow with Adaptive Kernel

Fuente: arXiv
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Main Authors: Chen, Yindong, Wang, Yiwei, Kang, Lulu, Liu, Chun
Format: Preprint
Published: 2021
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author Chen, Yindong
Wang, Yiwei
Kang, Lulu
Liu, Chun
author_facet Chen, Yindong
Wang, Yiwei
Kang, Lulu
Liu, Chun
contents We propose a novel deterministic sampling method to approximate a target distribution $ρ^*$ by minimizing the kernel discrepancy, also known as the Maximum Mean Discrepancy (MMD). By employing the general \emph{energetic variational inference} framework (Wang et al., 2021), we convert the problem of minimizing MMD to solving a dynamic ODE system of the particles. We adopt the implicit Euler numerical scheme to solve the ODE systems. This leads to a proximal minimization problem in each iteration of updating the particles, which can be solved by optimization algorithms such as L-BFGS. The proposed method is named EVI-MMD. To overcome the long-existing issue of bandwidth selection of the Gaussian kernel, we propose a novel way to specify the bandwidth dynamically. Through comprehensive numerical studies, we have shown the proposed adaptive bandwidth significantly improves the EVI-MMD. We use the EVI-MMD algorithm to solve two types of sampling problems. In the first type, the target distribution is given by a fully specified density function. The second type is a "two-sample problem", where only training data are available. The EVI-MMD method is used as a generative learning model to generate new samples that follow the same distribution as the training data. With the recommended settings of the tuning parameters, we show that the proposed EVI-MMD method outperforms some existing methods for both types of problems.
format Preprint
id arxiv_https___arxiv_org_abs_2111_10722
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle A Deterministic Sampling Method via Maximum Mean Discrepancy Flow with Adaptive Kernel
Chen, Yindong
Wang, Yiwei
Kang, Lulu
Liu, Chun
Machine Learning
Computation
We propose a novel deterministic sampling method to approximate a target distribution $ρ^*$ by minimizing the kernel discrepancy, also known as the Maximum Mean Discrepancy (MMD). By employing the general \emph{energetic variational inference} framework (Wang et al., 2021), we convert the problem of minimizing MMD to solving a dynamic ODE system of the particles. We adopt the implicit Euler numerical scheme to solve the ODE systems. This leads to a proximal minimization problem in each iteration of updating the particles, which can be solved by optimization algorithms such as L-BFGS. The proposed method is named EVI-MMD. To overcome the long-existing issue of bandwidth selection of the Gaussian kernel, we propose a novel way to specify the bandwidth dynamically. Through comprehensive numerical studies, we have shown the proposed adaptive bandwidth significantly improves the EVI-MMD. We use the EVI-MMD algorithm to solve two types of sampling problems. In the first type, the target distribution is given by a fully specified density function. The second type is a "two-sample problem", where only training data are available. The EVI-MMD method is used as a generative learning model to generate new samples that follow the same distribution as the training data. With the recommended settings of the tuning parameters, we show that the proposed EVI-MMD method outperforms some existing methods for both types of problems.
title A Deterministic Sampling Method via Maximum Mean Discrepancy Flow with Adaptive Kernel
topic Machine Learning
Computation
url https://arxiv.org/abs/2111.10722