Scalable Expectation Estimation with Subtractive Mixture Models

Fuente: arXiv
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Hauptverfasser: Zellinger, Lena, Branchini, Nicola, Elvira, Víctor, Vergari, Antonio
Format: Preprint
Veröffentlicht: 2025
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author Zellinger, Lena
Branchini, Nicola
Elvira, Víctor
Vergari, Antonio
author_facet Zellinger, Lena
Branchini, Nicola
Elvira, Víctor
Vergari, Antonio
contents Many Monte Carlo (MC) and importance sampling (IS) methods use mixture models (MMs) for their simplicity and ability to capture multimodal distributions. Recently, subtractive mixture models (SMMs), i.e. MMs with negative coefficients, have shown greater expressiveness and success in generative modeling. However, their negative parameters complicate sampling, requiring costly auto-regressive techniques or accept-reject algorithms that do not scale in high dimensions. In this work, we use the difference representation of SMMs to construct an unbiased IS estimator ($Δ\text{Ex}$) that removes the need to sample from the SMM, enabling high-dimensional expectation estimation with SMMs. In our experiments, we show that $Δ\text{Ex}$ can achieve comparable estimation quality to auto-regressive sampling while being considerably faster in MC estimation. Moreover, we conduct initial experiments with $Δ\text{Ex}$ using hand-crafted proposals, gaining first insights into how to construct safe proposals for $Δ\text{Ex}$.
format Preprint
id arxiv_https___arxiv_org_abs_2503_21346
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Scalable Expectation Estimation with Subtractive Mixture Models
Zellinger, Lena
Branchini, Nicola
Elvira, Víctor
Vergari, Antonio
Machine Learning
Computation
Many Monte Carlo (MC) and importance sampling (IS) methods use mixture models (MMs) for their simplicity and ability to capture multimodal distributions. Recently, subtractive mixture models (SMMs), i.e. MMs with negative coefficients, have shown greater expressiveness and success in generative modeling. However, their negative parameters complicate sampling, requiring costly auto-regressive techniques or accept-reject algorithms that do not scale in high dimensions. In this work, we use the difference representation of SMMs to construct an unbiased IS estimator ($Δ\text{Ex}$) that removes the need to sample from the SMM, enabling high-dimensional expectation estimation with SMMs. In our experiments, we show that $Δ\text{Ex}$ can achieve comparable estimation quality to auto-regressive sampling while being considerably faster in MC estimation. Moreover, we conduct initial experiments with $Δ\text{Ex}$ using hand-crafted proposals, gaining first insights into how to construct safe proposals for $Δ\text{Ex}$.
title Scalable Expectation Estimation with Subtractive Mixture Models
topic Machine Learning
Computation
url https://arxiv.org/abs/2503.21346