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Bibliographic Details
Main Authors: Boom, Willem van den, Cremaschi, Andrea, Thiery, Alexandre H.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2404.18556
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author Boom, Willem van den
Cremaschi, Andrea
Thiery, Alexandre H.
author_facet Boom, Willem van den
Cremaschi, Andrea
Thiery, Alexandre H.
contents We propose an adaptive importance sampling scheme for Gaussian approximations of intractable posteriors. Optimization-based approximations like variational inference can be too inaccurate while existing Monte Carlo methods can be too slow. Therefore, we propose a hybrid where, at each iteration, the Monte Carlo effective sample size can be guaranteed at a fixed computational cost by interpolating between natural-gradient variational inference and importance sampling. The amount of damping in the updates adapts to the posterior and guarantees the effective sample size. Gaussianity enables the use of Stein's lemma to obtain gradient-based optimization in the highly damped variational inference regime and a reduction of Monte Carlo error for undamped adaptive importance sampling. The result is a generic, embarrassingly parallel and adaptive posterior approximation method. Numerical studies on simulated and real data show its competitiveness with other, less general methods.
format Preprint
id arxiv_https___arxiv_org_abs_2404_18556
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Doubly Adaptive Importance Sampling
Boom, Willem van den
Cremaschi, Andrea
Thiery, Alexandre H.
Computation
We propose an adaptive importance sampling scheme for Gaussian approximations of intractable posteriors. Optimization-based approximations like variational inference can be too inaccurate while existing Monte Carlo methods can be too slow. Therefore, we propose a hybrid where, at each iteration, the Monte Carlo effective sample size can be guaranteed at a fixed computational cost by interpolating between natural-gradient variational inference and importance sampling. The amount of damping in the updates adapts to the posterior and guarantees the effective sample size. Gaussianity enables the use of Stein's lemma to obtain gradient-based optimization in the highly damped variational inference regime and a reduction of Monte Carlo error for undamped adaptive importance sampling. The result is a generic, embarrassingly parallel and adaptive posterior approximation method. Numerical studies on simulated and real data show its competitiveness with other, less general methods.
title Doubly Adaptive Importance Sampling
topic Computation
url https://arxiv.org/abs/2404.18556