Unexpected Improvements to Expected Improvement for Bayesian Optimization

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ament, Sebastian, Daulton, Samuel, Eriksson, David, Balandat, Maximilian, Bakshy, Eytan
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917885630218240
author Ament, Sebastian
Daulton, Samuel
Eriksson, David
Balandat, Maximilian
Bakshy, Eytan
author_facet Ament, Sebastian
Daulton, Samuel
Eriksson, David
Balandat, Maximilian
Bakshy, Eytan
contents Expected Improvement (EI) is arguably the most popular acquisition function in Bayesian optimization and has found countless successful applications, but its performance is often exceeded by that of more recent methods. Notably, EI and its variants, including for the parallel and multi-objective settings, are challenging to optimize because their acquisition values vanish numerically in many regions. This difficulty generally increases as the number of observations, dimensionality of the search space, or the number of constraints grow, resulting in performance that is inconsistent across the literature and most often sub-optimal. Herein, we propose LogEI, a new family of acquisition functions whose members either have identical or approximately equal optima as their canonical counterparts, but are substantially easier to optimize numerically. We demonstrate that numerical pathologies manifest themselves in "classic" analytic EI, Expected Hypervolume Improvement (EHVI), as well as their constrained, noisy, and parallel variants, and propose corresponding reformulations that remedy these pathologies. Our empirical results show that members of the LogEI family of acquisition functions substantially improve on the optimization performance of their canonical counterparts and surprisingly, are on par with or exceed the performance of recent state-of-the-art acquisition functions, highlighting the understated role of numerical optimization in the literature.
format Preprint
id arxiv_https___arxiv_org_abs_2310_20708
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Unexpected Improvements to Expected Improvement for Bayesian Optimization
Ament, Sebastian
Daulton, Samuel
Eriksson, David
Balandat, Maximilian
Bakshy, Eytan
Machine Learning
Numerical Analysis
Expected Improvement (EI) is arguably the most popular acquisition function in Bayesian optimization and has found countless successful applications, but its performance is often exceeded by that of more recent methods. Notably, EI and its variants, including for the parallel and multi-objective settings, are challenging to optimize because their acquisition values vanish numerically in many regions. This difficulty generally increases as the number of observations, dimensionality of the search space, or the number of constraints grow, resulting in performance that is inconsistent across the literature and most often sub-optimal. Herein, we propose LogEI, a new family of acquisition functions whose members either have identical or approximately equal optima as their canonical counterparts, but are substantially easier to optimize numerically. We demonstrate that numerical pathologies manifest themselves in "classic" analytic EI, Expected Hypervolume Improvement (EHVI), as well as their constrained, noisy, and parallel variants, and propose corresponding reformulations that remedy these pathologies. Our empirical results show that members of the LogEI family of acquisition functions substantially improve on the optimization performance of their canonical counterparts and surprisingly, are on par with or exceed the performance of recent state-of-the-art acquisition functions, highlighting the understated role of numerical optimization in the literature.
title Unexpected Improvements to Expected Improvement for Bayesian Optimization
topic Machine Learning
Numerical Analysis
url https://arxiv.org/abs/2310.20708