You're reading from Mastering Machine Learning Algorithms Expert techniques for implementing popular machine learning algorithms, fine-tuning your models, and understanding how they work

Product type Paperback

Published in Jan 2020

Publisher Packt

ISBN-13 9781838820299

Length 798 pages

Edition 2nd Edition

Languages

Python

Tools

Keras

Concepts

Machine Learning

Authors (2):

Giuseppe Bonaccorso

View More author details

Table of Contents (28) Chapters

Preface

1. Machine Learning Model Fundamentals

2. Loss Functions and Regularization FREE CHAPTER

3. Introduction to Semi-Supervised Learning

4. Advanced Semi-Supervised Classification

5. Graph-Based Semi-Supervised Learning

6. Clustering and Unsupervised Models

7. Advanced Clustering and Unsupervised Models

8. Clustering and Unsupervised Models for Marketing

9. Generalized Linear Models and Regression

10. Introduction to Time-Series Analysis

11. Bayesian Networks and Hidden Markov Models

12. The EM Algorithm

13. Component Analysis and Dimensionality Reduction

14. Hebbian Learning

15. Fundamentals of Ensemble Learning

16. Advanced Boosting Algorithms

17. Modeling Neural Networks

18. Optimizing Neural Networks

19. Deep Convolutional Networks

20. Recurrent Neural Networks

21. Autoencoders

22. Introduction to Generative Adversarial Networks

23. Deep Belief Networks

24. Introduction to Reinforcement Learning

25. Advanced Policy Estimation Algorithms

26. Other Books You May Enjoy

27. Index

SARSA algorithm

SARSA (the name is derived from the sequence state-action-reward-state-action) is a natural extension of TD(0) to the estimation of the Q function. Its standard formulation (which is sometimes called one-step SARSA, or SARSA(0), for the same reasons explained in the previous chapter) is based on a single next reward r_t₊₁, which is obtained by executing the action a_t in the state s_t. The temporal difference computation is based on the following update rule:

The equation is equivalent to TD(0), and if the policy is chosen to be GLIE, it has been proven (in Singh S., Jaakkola T., Littman M. L., Szepesvári C., Convergence Results for Single-Step On-Policy Reinforcement-Learning Algorithms, Machine Learning, 39/2000) that SARSA converges to an optimal policy with a probability of 1 when all couples (state, action) are experienced an infinite number of times. This means that if the policy is updated to be greedy with respect to the current value function induced...