Book Image

Hyperparameter Tuning with Python

By : Louis Owen
Book Image

Hyperparameter Tuning with Python

By: Louis Owen

Overview of this book

Hyperparameters are an important element in building useful machine learning models. This book curates numerous hyperparameter tuning methods for Python, one of the most popular coding languages for machine learning. Alongside in-depth explanations of how each method works, you will use a decision map that can help you identify the best tuning method for your requirements. You’ll start with an introduction to hyperparameter tuning and understand why it's important. Next, you'll learn the best methods for hyperparameter tuning for a variety of use cases and specific algorithm types. This book will not only cover the usual grid or random search but also other powerful underdog methods. Individual chapters are also dedicated to the three main groups of hyperparameter tuning methods: exhaustive search, heuristic search, Bayesian optimization, and multi-fidelity optimization. Later, you will learn about top frameworks like Scikit, Hyperopt, Optuna, NNI, and DEAP to implement hyperparameter tuning. Finally, you will cover hyperparameters of popular algorithms and best practices that will help you efficiently tune your hyperparameter. By the end of this book, you will have the skills you need to take full control over your machine learning models and get the best models for the best results.
Table of Contents (19 chapters)
1
Section 1:The Methods
8
Section 2:The Implementation
13
Section 3:Putting Things into Practice

Understanding hyperparameter space 
and distributions

Hyperparameter space is defined as the universal set of possible hyperparameter value combinations—in other words, it is the space containing all possible hyperparameter values that will be used as the search space during the hyperparameter-tuning phase. That's why it is also often called the hyperparameter-tuning search space. This space is predefined before the hyperparameter-tuning phase so that the search will be performed only on this space.

For example, we want to perform hyperparameter tuning on a NN. Let's say we want to search what is the best value for the dropout rate, the number of epochs, and batch-size hyperparameters.

The dropout rate is bounded in nature. Its value can only be between 0 and 1, while for the number of epochs and batch-size hyperparameters, in theory, we can specify any positive integer value. However, there are other considerations that we need to think of. A higher...