Book Image

Ensemble Machine Learning Cookbook

By : Dipayan Sarkar, Vijayalakshmi Natarajan
Book Image

Ensemble Machine Learning Cookbook

By: Dipayan Sarkar, Vijayalakshmi Natarajan

Overview of this book

Ensemble modeling is an approach used to improve the performance of machine learning models. It combines two or more similar or dissimilar machine learning algorithms to deliver superior intellectual powers. This book will help you to implement popular machine learning algorithms to cover different paradigms of ensemble machine learning such as boosting, bagging, and stacking. The Ensemble Machine Learning Cookbook will start by getting you acquainted with the basics of ensemble techniques and exploratory data analysis. You'll then learn to implement tasks related to statistical and machine learning algorithms to understand the ensemble of multiple heterogeneous algorithms. It will also ensure that you don't miss out on key topics, such as like resampling methods. As you progress, you’ll get a better understanding of bagging, boosting, stacking, and working with the Random Forest algorithm using real-world examples. The book will highlight how these ensemble methods use multiple models to improve machine learning results, as compared to a single model. In the concluding chapters, you'll delve into advanced ensemble models using neural networks, natural language processing, and more. You’ll also be able to implement models such as fraud detection, text categorization, and sentiment analysis. By the end of this book, you'll be able to harness ensemble techniques and the working mechanisms of machine learning algorithms to build intelligent models using individual recipes.
Table of Contents (14 chapters)

Decision trees

Decision trees, a non-parametric supervised learning method, are popular algorithms used for predictive modeling. The most well-known decision tree algorithms include the iterative dichotomizer (ID3), C4.5, CART, and C5.0. ID3 is only applicable for categorical features. C4.5 is an improvement on ID3 and has the ability to handle missing values and continuous attributes. The tree-growing process involves finding the best split at each node using the information gain. However, the C4.5 algorithm converts a continuous attribute into a dichotomous categorical attribute by splitting at a suitable threshold value that can produce maximum information gain.

Leo Breiman, a distinguished statistician, introduced a decision tree algorithm called the Classification and Regression Tree (CART). CART, unlike ID3 and C4.5, can produce decision trees that can be used for both...