Book Image

Deep Learning from the Basics

By : Koki Saitoh
5 (1)
Book Image

Deep Learning from the Basics

5 (1)
By: Koki Saitoh

Overview of this book

Deep learning is rapidly becoming the most preferred way of solving data problems. This is thanks, in part, to its huge variety of mathematical algorithms and their ability to find patterns that are otherwise invisible to us. Deep Learning from the Basics begins with a fast-paced introduction to deep learning with Python, its definition, characteristics, and applications. You’ll learn how to use the Python interpreter and the script files in your applications, and utilize NumPy and Matplotlib in your deep learning models. As you progress through the book, you’ll discover backpropagation—an efficient way to calculate the gradients of weight parameters—and study multilayer perceptrons and their limitations, before, finally, implementing a three-layer neural network and calculating multidimensional arrays. By the end of the book, you’ll have the knowledge to apply the relevant technologies in deep learning.
Table of Contents (11 chapters)

Chain Rule

Forward propagation in a computational graph propagates the calculation result in the forward direction from left to right. These calculations seem natural because they are usually conducted. On the other hand, in backward propagation, a "local derivative" is propagated in the backward direction from right to left. The principle that propagates the "local derivative" is based on the chain rule. Let's look at the chain rule and clarify how it corresponds to backward propagation in a computational graph.

Backward Propagation in a Computational Graph

We will now look at an example of backward propagation using a computational graph. Let's assume that a calculation, y = f (x), exists. The following diagram shows the backward propagation of this calculation:

Figure 5.6: Backward propagation in a computational graph – the local derivative is multiplied in the backward direction

As shown in the preceding diagram...