Book Image

Python Deep Learning

By : Valentino Zocca, Gianmario Spacagna, Daniel Slater, Peter Roelants
Book Image

Python Deep Learning

By: Valentino Zocca, Gianmario Spacagna, Daniel Slater, Peter Roelants

Overview of this book

With an increasing interest in AI around the world, deep learning has attracted a great deal of public attention. Every day, deep learning algorithms are used broadly across different industries. The book will give you all the practical information available on the subject, including the best practices, using real-world use cases. You will learn to recognize and extract information to increase predictive accuracy and optimize results. Starting with a quick recap of important machine learning concepts, the book will delve straight into deep learning principles using Sci-kit learn. Moving ahead, you will learn to use the latest open source libraries such as Theano, Keras, Google's TensorFlow, and H20. Use this guide to uncover the difficulties of pattern recognition, scaling data with greater accuracy and discussing deep learning algorithms and techniques. Whether you want to dive deeper into Deep Learning, or want to investigate how to get more out of this powerful technology, you’ll find everything inside.
Table of Contents (18 chapters)
Python Deep Learning
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Recurrent neural networks


RNNs get their name because they recurrently apply the same function over a sequence. An RNN can be written as a recurrence relation defined by this function:

St = f(St-1, Xt)

Here St —the state at step t—is computed by the function f from the state in the previous step, that is t-1, and an input Xt at the current step. This recurrence relation defines how the state evolves step by step over the sequence via a feedback loop over previous states, as illustrated in the following figure:

Figure from [3]

Left: Visual illustration of the RNN recurrence relation: S t = S t-1 * W + X t * U. The final output will be o t = V*S t

Right: RNN states recurrently unfolded over the sequence t- 1, t, t+1. Note that the parameters U, V, and W are shared between all the steps.

Here f can be any differentiable function. For example, a basic RNN is defined by the following recurrence relation:

St = tanh(St-1 * W + Xt * U)

Here W defines a linear transformation from state to state...