Rethinking the Diffusion Models for Numerical Tabular Data Imputation from the Perspective of Wasserstein Gradient Flow

Fuente: arXiv
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Main Authors: Chen, Zhichao, Li, Haoxuan, Wang, Fangyikang, Zhang, Odin, Xu, Hu, Jiang, Xiaoyu, Song, Zhihuan, Wang, Eric H.
Format: Preprint
Published: 2024
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author Chen, Zhichao
Li, Haoxuan
Wang, Fangyikang
Zhang, Odin
Xu, Hu
Jiang, Xiaoyu
Song, Zhihuan
Wang, Eric H.
author_facet Chen, Zhichao
Li, Haoxuan
Wang, Fangyikang
Zhang, Odin
Xu, Hu
Jiang, Xiaoyu
Song, Zhihuan
Wang, Eric H.
contents Diffusion models (DMs) have gained attention in Missing Data Imputation (MDI), but there remain two long-neglected issues to be addressed: (1). Inaccurate Imputation, which arises from inherently sample-diversification-pursuing generative process of DMs. (2). Difficult Training, which stems from intricate design required for the mask matrix in model training stage. To address these concerns within the realm of numerical tabular datasets, we introduce a novel principled approach termed Kernelized Negative Entropy-regularized Wasserstein gradient flow Imputation (KnewImp). Specifically, based on Wasserstein gradient flow (WGF) framework, we first prove that issue (1) stems from the cost functionals implicitly maximized in DM-based MDI are equivalent to the MDI's objective plus diversification-promoting non-negative terms. Based on this, we then design a novel cost functional with diversification-discouraging negative entropy and derive our KnewImp approach within WGF framework and reproducing kernel Hilbert space. After that, we prove that the imputation procedure of KnewImp can be derived from another cost functional related to the joint distribution, eliminating the need for the mask matrix and hence naturally addressing issue (2). Extensive experiments demonstrate that our proposed KnewImp approach significantly outperforms existing state-of-the-art methods.
format Preprint
id arxiv_https___arxiv_org_abs_2406_15762
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Rethinking the Diffusion Models for Numerical Tabular Data Imputation from the Perspective of Wasserstein Gradient Flow
Chen, Zhichao
Li, Haoxuan
Wang, Fangyikang
Zhang, Odin
Xu, Hu
Jiang, Xiaoyu
Song, Zhihuan
Wang, Eric H.
Machine Learning
Diffusion models (DMs) have gained attention in Missing Data Imputation (MDI), but there remain two long-neglected issues to be addressed: (1). Inaccurate Imputation, which arises from inherently sample-diversification-pursuing generative process of DMs. (2). Difficult Training, which stems from intricate design required for the mask matrix in model training stage. To address these concerns within the realm of numerical tabular datasets, we introduce a novel principled approach termed Kernelized Negative Entropy-regularized Wasserstein gradient flow Imputation (KnewImp). Specifically, based on Wasserstein gradient flow (WGF) framework, we first prove that issue (1) stems from the cost functionals implicitly maximized in DM-based MDI are equivalent to the MDI's objective plus diversification-promoting non-negative terms. Based on this, we then design a novel cost functional with diversification-discouraging negative entropy and derive our KnewImp approach within WGF framework and reproducing kernel Hilbert space. After that, we prove that the imputation procedure of KnewImp can be derived from another cost functional related to the joint distribution, eliminating the need for the mask matrix and hence naturally addressing issue (2). Extensive experiments demonstrate that our proposed KnewImp approach significantly outperforms existing state-of-the-art methods.
title Rethinking the Diffusion Models for Numerical Tabular Data Imputation from the Perspective of Wasserstein Gradient Flow
topic Machine Learning
url https://arxiv.org/abs/2406.15762