Book Image

Reinforcement Learning Algorithms with Python

By : Andrea Lonza
Book Image

Reinforcement Learning Algorithms with Python

By: Andrea Lonza

Overview of this book

Reinforcement Learning (RL) is a popular and promising branch of AI that involves making smarter models and agents that can automatically determine ideal behavior based on changing requirements. This book will help you master RL algorithms and understand their implementation as you build self-learning agents. Starting with an introduction to the tools, libraries, and setup needed to work in the RL environment, this book covers the building blocks of RL and delves into value-based methods, such as the application of Q-learning and SARSA algorithms. You'll learn how to use a combination of Q-learning and neural networks to solve complex problems. Furthermore, you'll study the policy gradient methods, TRPO, and PPO, to improve performance and stability, before moving on to the DDPG and TD3 deterministic algorithms. This book also covers how imitation learning techniques work and how Dagger can teach an agent to drive. You'll discover evolutionary strategies and black-box optimization techniques, and see how they can improve RL algorithms. Finally, you'll get to grips with exploration approaches, such as UCB and UCB1, and develop a meta-algorithm called ESBAS. By the end of the book, you'll have worked with key RL algorithms to overcome challenges in real-world applications, and be part of the RL research community.
Table of Contents (19 chapters)
Free Chapter
1
Section 1: Algorithms and Environments
5
Section 2: Model-Free RL Algorithms
11
Section 3: Beyond Model-Free Algorithms and Improvements
17
Assessments

DQN applied to Pong

Equipped with all the technical knowledge about Q-learning, deep neural networks, and DQN, we can finally put it to work and start to warm up the GPU. In this section, we will apply DQN to an Atari environment, Pong. We have chosen Pong rather than all the other Atari environments because it's simpler to solve and thus requires less time, computational power, and memory. That being said, if you have a decent GPU available, you can apply the same exact configuration to almost all the other Atari games (some may require a little bit of fine-tuning). For the same reason, we adopted a lighter configuration compared to the original DQN paper, both in terms of the capacity of the function approximator (that is, fewer weights) and hyperparameters such as a smaller buffer size. This does not compromise the results rather on Pong but might degrade the performance...