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 4. Cluster Analysis

Unsupervised cluster analysis refers to algorithms that aim at producing homogeneous groups of cases from unlabeled data. The algorithm doesn't know beforehand what the membership to the groups is, and its goal is to find the structure of the data from similarities (or differences) between the cases; a cluster is a group of cases, observations, individuals, or other units, that are similar to each other on the considered characteristics. These characteristics can be anything measurable or observable. The choice of characteristics, or attributes, is important as different attributes will lead to different clusters.

In this chapter, we will discuss the following topics:

  • Distance measures

  • Partition clustering with k-means, including the steps in the computations of clusters, and the selection of the best number of clusters

  • Applications of k-means clustering

Clustering algorithms use distance measures between the cases in order to create these homogeneous groups of cases...