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

Scatterplots


Until now we have observed frequencies of the relationship between categorical membership (nominal attributes) and frequencies or means. It is also useful to have a look at relationships between numerical attributes. We will rely on scatterplots for this purpose. This will require a little scripting again, as we will examine the relationships between proportions. Let me first introduce the function proportions() which will generate the proportions for us, for all of our nominal attributes. This function takes one argument, DF, and call our attributes() function by default. We could instead give as an argument the data frame with the numbers we have previously drawn and the attributes.

The body of the function computes and returns the transpose of the means of each nominal attributes:

1    proportions = function(n = 100) {
2       DF=attributes(n)
3       return(data.frame(t(colMeans(DF[3:ncol(DF)]))))
4    }

The body of this function calls our attributes() function and passes...