Book Image

PyTorch 1.x Reinforcement Learning Cookbook

By : Yuxi (Hayden) Liu
Book Image

PyTorch 1.x Reinforcement Learning Cookbook

By: Yuxi (Hayden) Liu

Overview of this book

Reinforcement learning (RL) is a branch of machine learning that has gained popularity in recent times. It allows you to train AI models that learn from their own actions and optimize their behavior. PyTorch has also emerged as the preferred tool for training RL models because of its efficiency and ease of use. With this book, you'll explore the important RL concepts and the implementation of algorithms in PyTorch 1.x. The recipes in the book, along with real-world examples, will help you master various RL techniques, such as dynamic programming, Monte Carlo simulations, temporal difference, and Q-learning. You'll also gain insights into industry-specific applications of these techniques. Later chapters will guide you through solving problems such as the multi-armed bandit problem and the cartpole problem using the multi-armed bandit algorithm and function approximation. You'll also learn how to use Deep Q-Networks to complete Atari games, along with how to effectively implement policy gradients. Finally, you'll discover how RL techniques are applied to Blackjack, Gridworld environments, internet advertising, and the Flappy Bird game. By the end of this book, you'll have developed the skills you need to implement popular RL algorithms and use RL techniques to solve real-world problems.
Table of Contents (11 chapters)

Solving internet advertising problems with contextual bandits

You may notice that in the ad optimization problem, we only care about the ad and ignore other information, such as user information and web page information, that might affect the ad being clicked on or not. In this recipe, we will talk about how we take more information into account beyond the ad itself and solve the problem with contextual bandits.

The multi-armed bandit problems we have worked with so far do not involve the concept of state, which is very different from MDPs. We only have several actions, and a reward will be generated that is associated with the action selected. Contextual bandits extend multi-armed bandits by introducing the concept of state. State provides a description of the environment, which helps the agent take more informed actions. In the advertising example, the state could be the user...