Book Image

Python: Advanced Guide to Artificial Intelligence

By : Giuseppe Bonaccorso, Rajalingappaa Shanmugamani
Book Image

Python: Advanced Guide to Artificial Intelligence

By: Giuseppe Bonaccorso, Rajalingappaa Shanmugamani

Overview of this book

This Learning Path is your complete guide to quickly getting to grips with popular machine learning algorithms. You'll be introduced to the most widely used algorithms in supervised, unsupervised, and semi-supervised machine learning, and learn how to use them in the best possible manner. Ranging from Bayesian models to the MCMC algorithm to Hidden Markov models, this Learning Path will teach you how to extract features from your dataset and perform dimensionality reduction by making use of Python-based libraries. You'll bring the use of TensorFlow and Keras to build deep learning models, using concepts such as transfer learning, generative adversarial networks, and deep reinforcement learning. Next, you'll learn the advanced features of TensorFlow1.x, such as distributed TensorFlow with TF clusters, deploy production models with TensorFlow Serving. You'll implement different techniques related to object classification, object detection, image segmentation, and more. By the end of this Learning Path, you'll have obtained in-depth knowledge of TensorFlow, making you the go-to person for solving artificial intelligence problems This Learning Path includes content from the following Packt products: • Mastering Machine Learning Algorithms by Giuseppe Bonaccorso • Mastering TensorFlow 1.x by Armando Fandango • Deep Learning for Computer Vision by Rajalingappaa Shanmugamani
Table of Contents (31 chapters)
Title Page
About Packt
Contributors
Preface
19
Tensor Processing Units
Index

Implementing Q-Learning


Q-Learning is a model-free method of finding the optimal policy that can maximize the reward of an agent. During initial gameplay, the agent learns a Q value for each pair of (state, action), also known as the exploration strategy, as explained in previous sections. Once the Q values are learned, then the optimal policy will be to select an action with the largest Q-value in every state, also known as the exploitation strategy. The learning algorithm may end in locally optimal solutions, hence we keep using the exploration policy by setting an exploration_rate parameter.

The Q-Learning algorithm is as follows:

initialize Q(shape=[#s,#a]) to random values or zeroes
Repeat (for each episode)
    observe current state s
    Repeat
        select an action a (apply explore or exploit strategy)
        observe state s_next as a result of action a
        update the Q-Table using bellman's equation
        set current state s = s_next       
    until the episode ends or...