Search Results for author: Gregory Farquhar

Found 22 papers, 17 papers with code

An Investigation of the Bias-Variance Tradeoff in Meta-Gradients

1 code implementation22 Sep 2022 Risto Vuorio, Jacob Beck, Shimon Whiteson, Jakob Foerster, Gregory Farquhar

Meta-gradients provide a general approach for optimizing the meta-parameters of reinforcement learning (RL) algorithms.

Meta-Learning Reinforcement Learning (RL)

Model-Value Inconsistency as a Signal for Epistemic Uncertainty

no code implementations8 Dec 2021 Angelos Filos, Eszter Vértes, Zita Marinho, Gregory Farquhar, Diana Borsa, Abram Friesen, Feryal Behbahani, Tom Schaul, André Barreto, Simon Osindero

Unlike prior work which estimates uncertainty by training an ensemble of many models and/or value functions, this approach requires only the single model and value function which are already being learned in most model-based reinforcement learning algorithms.

Model-based Reinforcement Learning Rolling Shutter Correction

Self-Consistent Models and Values

no code implementations NeurIPS 2021 Gregory Farquhar, Kate Baumli, Zita Marinho, Angelos Filos, Matteo Hessel, Hado van Hasselt, David Silver

Learned models of the environment provide reinforcement learning (RL) agents with flexible ways of making predictions about the environment.

reinforcement-learning Reinforcement Learning (RL)

Proper Value Equivalence

1 code implementation NeurIPS 2021 Christopher Grimm, André Barreto, Gregory Farquhar, David Silver, Satinder Singh

The value-equivalence (VE) principle proposes a simple answer to this question: a model should capture the aspects of the environment that are relevant for value-based planning.

Model-based Reinforcement Learning Reinforcement Learning (RL)

Weighted QMIX: Expanding Monotonic Value Function Factorisation for Deep Multi-Agent Reinforcement Learning

4 code implementations NeurIPS 2020 Tabish Rashid, Gregory Farquhar, Bei Peng, Shimon Whiteson

We show in particular that this projection can fail to recover the optimal policy even with access to $Q^*$, which primarily stems from the equal weighting placed on each joint action.

Multi-agent Reinforcement Learning Q-Learning +3

Monotonic Value Function Factorisation for Deep Multi-Agent Reinforcement Learning

1 code implementation19 Mar 2020 Tabish Rashid, Mikayel Samvelyan, Christian Schroeder de Witt, Gregory Farquhar, Jakob Foerster, Shimon Whiteson

At the same time, it is often possible to train the agents in a centralised fashion where global state information is available and communication constraints are lifted.

reinforcement-learning Reinforcement Learning (RL) +2

Loaded DiCE: Trading off Bias and Variance in Any-Order Score Function Estimators for Reinforcement Learning

1 code implementation23 Sep 2019 Gregory Farquhar, Shimon Whiteson, Jakob Foerster

Gradient-based methods for optimisation of objectives in stochastic settings with unknown or intractable dynamics require estimators of derivatives.

Continuous Control Meta Reinforcement Learning +2

Growing Action Spaces

1 code implementation ICML 2020 Gregory Farquhar, Laura Gustafson, Zeming Lin, Shimon Whiteson, Nicolas Usunier, Gabriel Synnaeve

In complex tasks, such as those with large combinatorial action spaces, random exploration may be too inefficient to achieve meaningful learning progress.

reinforcement-learning Reinforcement Learning (RL) +1

A Survey of Reinforcement Learning Informed by Natural Language

no code implementations10 Jun 2019 Jelena Luketina, Nantas Nardelli, Gregory Farquhar, Jakob Foerster, Jacob Andreas, Edward Grefenstette, Shimon Whiteson, Tim Rocktäschel

To be successful in real-world tasks, Reinforcement Learning (RL) needs to exploit the compositional, relational, and hierarchical structure of the world, and learn to transfer it to the task at hand.

Decision Making Instruction Following +5

DiCE: The Infinitely Differentiable Monte Carlo Estimator

1 code implementation ICML 2018 Jakob Foerster, Gregory Farquhar, Maruan Al-Shedivat, Tim Rocktäschel, Eric Xing, Shimon Whiteson

Lastly, to match the first-order gradient under differentiation, SL treats part of the cost as a fixed sample, which we show leads to missing and wrong terms for estimators of higher-order derivatives.

Meta-Learning

QMIX: Monotonic Value Function Factorisation for Deep Multi-Agent Reinforcement Learning

16 code implementations ICML 2018 Tabish Rashid, Mikayel Samvelyan, Christian Schroeder de Witt, Gregory Farquhar, Jakob Foerster, Shimon Whiteson

At the same time, it is often possible to train the agents in a centralised fashion in a simulated or laboratory setting, where global state information is available and communication constraints are lifted.

Multi-agent Reinforcement Learning reinforcement-learning +4

DiCE: The Infinitely Differentiable Monte-Carlo Estimator

5 code implementations14 Feb 2018 Jakob Foerster, Gregory Farquhar, Maruan Al-Shedivat, Tim Rocktäschel, Eric P. Xing, Shimon Whiteson

Lastly, to match the first-order gradient under differentiation, SL treats part of the cost as a fixed sample, which we show leads to missing and wrong terms for estimators of higher-order derivatives.

Meta-Learning

TreeQN and ATreeC: Differentiable Tree-Structured Models for Deep Reinforcement Learning

1 code implementation ICLR 2018 Gregory Farquhar, Tim Rocktäschel, Maximilian Igl, Shimon Whiteson

To address these challenges, we propose TreeQN, a differentiable, recursive, tree-structured model that serves as a drop-in replacement for any value function network in deep RL with discrete actions.

Atari Games reinforcement-learning +2

Counterfactual Multi-Agent Policy Gradients

6 code implementations24 May 2017 Jakob Foerster, Gregory Farquhar, Triantafyllos Afouras, Nantas Nardelli, Shimon Whiteson

COMA uses a centralised critic to estimate the Q-function and decentralised actors to optimise the agents' policies.

Autonomous Vehicles counterfactual +2

Cannot find the paper you are looking for? You can Submit a new open access paper.