Book Image

Mastering Machine Learning with scikit-learn - Second Edition

By : Gavin Hackeling
Book Image

Mastering Machine Learning with scikit-learn - Second Edition

By: Gavin Hackeling

Overview of this book

Machine learning is the buzzword bringing computer science and statistics together to build smart and efficient models. Using powerful algorithms and techniques offered by machine learning you can automate any analytical model. This book examines a variety of machine learning models including popular machine learning algorithms such as k-nearest neighbors, logistic regression, naive Bayes, k-means, decision trees, and artificial neural networks. It discusses data preprocessing, hyperparameter optimization, and ensemble methods. You will build systems that classify documents, recognize images, detect ads, and more. You will learn to use scikit-learn’s API to extract features from categorical variables, text and images; evaluate model performance, and develop an intuition for how to improve your model’s performance. By the end of this book, you will master all required concepts of scikit-learn to build efficient models at work to carry out advanced tasks with the practical approach.
Table of Contents (22 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
9
From Decision Trees to Random Forests and Other Ensemble Methods
Index

Chapter 7. Naive Bayes

In previous chapters, we introduced two models for classification tasks: k-Nearest Neighbors (KNN) and logistic regression. In this chapter, we will introduce another family of classifiers called Naive Bayes. Named for its use of Bayes' theorem and for its naive assumption that all features are conditionally independent of each other given the response variable, Naive Bayes is the first generative model that we will discuss. First, we will introduce Bayes' theorem. Next, we will compare generative and discriminative models. We will discuss Naive Bayes and its assumptions and examine its common variants. Finally, we will fit a model using scikit-learn.