Book Image

Deep Reinforcement Learning with Python - Second Edition

By : Sudharsan Ravichandiran
Book Image

Deep Reinforcement Learning with Python - Second Edition

By: Sudharsan Ravichandiran

Overview of this book

With significant enhancements in the quality and quantity of algorithms in recent years, this second edition of Hands-On Reinforcement Learning with Python has been revamped into an example-rich guide to learning state-of-the-art reinforcement learning (RL) and deep RL algorithms with TensorFlow 2 and the OpenAI Gym toolkit. In addition to exploring RL basics and foundational concepts such as Bellman equation, Markov decision processes, and dynamic programming algorithms, this second edition dives deep into the full spectrum of value-based, policy-based, and actor-critic RL methods. It explores state-of-the-art algorithms such as DQN, TRPO, PPO and ACKTR, DDPG, TD3, and SAC in depth, demystifying the underlying math and demonstrating implementations through simple code examples. The book has several new chapters dedicated to new RL techniques, including distributional RL, imitation learning, inverse RL, and meta RL. You will learn to leverage stable baselines, an improvement of OpenAI’s baseline library, to effortlessly implement popular RL algorithms. The book concludes with an overview of promising approaches such as meta-learning and imagination augmented agents in research. By the end, you will become skilled in effectively employing RL and deep RL in your real-world projects.
Table of Contents (22 chapters)
18
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Index

Understanding Temporal Difference Learning

Temporal difference (TD) learning is one of the most popular and widely used model-free methods. The reason for this is that TD learning combines the advantages of both the dynamic programming (DP) method and the Monte Carlo (MC) method we covered in the previous chapters.

We will begin the chapter by understanding how exactly TD learning is beneficial compared to DP and MC methods. Later, we will learn how to perform the prediction task using TD learning. Going forward, we will learn how to perform TD control tasks with an on-policy TD control method called SARSA and an off-policy TD control method called Q learning.

We will also learn how to find the optimal policy in the Frozen Lake environment using SARSA and the Q learning method. At the end of the chapter, we will compare the DP, MC, and TD methods.

Thus, in this chapter, we will learn about the following topics:

  • TD learning
  • TD prediction method
  • TD...