Distributional Reinforcement Learning with Dual Expectile-Quantile Regression

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Jullien, Sami, Deffayet, Romain, Renders, Jean-Michel, Groth, Paul, de Rijke, Maarten
Natura: Preprint
Pubblicazione: 2023
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866910967818878976
author Jullien, Sami
Deffayet, Romain
Renders, Jean-Michel
Groth, Paul
de Rijke, Maarten
author_facet Jullien, Sami
Deffayet, Romain
Renders, Jean-Michel
Groth, Paul
de Rijke, Maarten
contents Distributional reinforcement learning (RL) has proven useful in multiple benchmarks as it enables approximating the full distribution of returns and extracts rich feedback from environment samples. The commonly used quantile regression approach to distributional RL -- based on asymmetric $L_1$ losses -- provides a flexible and effective way of learning arbitrary return distributions. In practice, it is often improved by using a more efficient, asymmetric hybrid $L_1$-$L_2$ Huber loss for quantile regression. However, by doing so, distributional estimation guarantees vanish, and we empirically observe that the estimated distribution rapidly collapses to its mean. Indeed, asymmetric $L_2$ losses, corresponding to expectile regression, cannot be readily used for distributional temporal difference. Motivated by the efficiency of $L_2$-based learning, we propose to jointly learn expectiles and quantiles of the return distribution in a way that allows efficient learning while keeping an estimate of the full distribution of returns. We prove that our proposed operator converges to the distributional Bellman operator in the limit of infinite estimated quantile and expectile fractions, and we benchmark a practical implementation on a toy example and at scale. On the Atari benchmark, our approach matches the performance of the Huber-based IQN-1 baseline after $200$M training frames but avoids distributional collapse and keeps estimates of the full distribution of returns.
format Preprint
id arxiv_https___arxiv_org_abs_2305_16877
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Distributional Reinforcement Learning with Dual Expectile-Quantile Regression
Jullien, Sami
Deffayet, Romain
Renders, Jean-Michel
Groth, Paul
de Rijke, Maarten
Machine Learning
Artificial Intelligence
I.2.8; G.3
Distributional reinforcement learning (RL) has proven useful in multiple benchmarks as it enables approximating the full distribution of returns and extracts rich feedback from environment samples. The commonly used quantile regression approach to distributional RL -- based on asymmetric $L_1$ losses -- provides a flexible and effective way of learning arbitrary return distributions. In practice, it is often improved by using a more efficient, asymmetric hybrid $L_1$-$L_2$ Huber loss for quantile regression. However, by doing so, distributional estimation guarantees vanish, and we empirically observe that the estimated distribution rapidly collapses to its mean. Indeed, asymmetric $L_2$ losses, corresponding to expectile regression, cannot be readily used for distributional temporal difference. Motivated by the efficiency of $L_2$-based learning, we propose to jointly learn expectiles and quantiles of the return distribution in a way that allows efficient learning while keeping an estimate of the full distribution of returns. We prove that our proposed operator converges to the distributional Bellman operator in the limit of infinite estimated quantile and expectile fractions, and we benchmark a practical implementation on a toy example and at scale. On the Atari benchmark, our approach matches the performance of the Huber-based IQN-1 baseline after $200$M training frames but avoids distributional collapse and keeps estimates of the full distribution of returns.
title Distributional Reinforcement Learning with Dual Expectile-Quantile Regression
topic Machine Learning
Artificial Intelligence
I.2.8; G.3
url https://arxiv.org/abs/2305.16877