Book Image

Learning Predictive Analytics with R

By : Eric Mayor
Book Image

Learning Predictive Analytics with R

By: Eric Mayor

Overview of this book

This book is packed with easy-to-follow guidelines that explain the workings of the many key data mining tools of R, which are used to discover knowledge from your data. You will learn how to perform key predictive analytics tasks using R, such as train and test predictive models for classification and regression tasks, score new data sets and so on. All chapters will guide you in acquiring the skills in a practical way. Most chapters also include a theoretical introduction that will sharpen your understanding of the subject matter and invite you to go further. The book familiarizes you with the most common data mining tools of R, such as k-means, hierarchical regression, linear regression, association rules, principal component analysis, multilevel modeling, k-NN, Naïve Bayes, decision trees, and text mining. It also provides a description of visualization techniques using the basic visualization tools of R as well as lattice for visualizing patterns in data organized in groups. This book is invaluable for anyone fascinated by the data mining opportunities offered by GNU R and its packages.
Table of Contents (23 chapters)
Learning Predictive Analytics with R
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Exercises and Solutions
Index

Chapter 11. Classification Trees

In Chapter 9, Linear Regression we discussed regression. In the previous chapter, we were interested in classification using k-NN and Naïve Bayes. In this chapter, we will continue the topic of classification and discuss it in the context of decision trees. Decision trees notably allow class predictions (group membership) of previously unseen observations (testing datasets or prediction datasets) using statistical criteria applied on the seen data (training set).

Here, we will briefly examine the statistical criteria of six algorithms:

  • ID3

  • C4.5

  • C5.0

  • Classification and regression trees (CART)

  • Random forest

  • Conditional inference trees

We will also examine how to use decision trees in R, notably, how to measure the reliability of the classifications using training and test sets.