Book Image

Practical Predictive Analytics

By : Ralph Winters
Book Image

Practical Predictive Analytics

By: Ralph Winters

Overview of this book

This is the go-to book for anyone interested in the steps needed to develop predictive analytics solutions with examples from the world of marketing, healthcare, and retail. We'll get started with a brief history of predictive analytics and learn about different roles and functions people play within a predictive analytics project. Then, we will learn about various ways of installing R along with their pros and cons, combined with a step-by-step installation of RStudio, and a description of the best practices for organizing your projects. On completing the installation, we will begin to acquire the skills necessary to input, clean, and prepare your data for modeling. We will learn the six specific steps needed to implement and successfully deploy a predictive model starting from asking the right questions through model development and ending with deploying your predictive model into production. We will learn why collaboration is important and how agile iterative modeling cycles can increase your chances of developing and deploying the best successful model. We will continue your journey in the cloud by extending your skill set by learning about Databricks and SparkR, which allow you to develop predictive models on vast gigabytes of data.
Table of Contents (19 chapters)
Title Page
About the Author
About the Reviewers
Customer Feedback

Converting to a document term matrix

Once we have a corpus, we can proceed to convert it to a document term matrix. When building DTM, care must be given to limiting the amount of data and resulting terms that are processed. If not parameterized correctly, it can take a very long time to run. Parameterization is accomplished via the options. We will remove any stopwords, punctuation, and numbers. Additionally, we will only include a minimum word length of four:

 dtm <- DocumentTermMatrix(corp, control = list(removePunctuation = TRUE, wordLengths = c(4, 
 999), stopwords = TRUE, removeNumbers = TRUE, stemming = FALSE, bounds = list(global = c(5, 

We can begin to look at the data by using the inspect() function.

This is different from the inspect() function in an arules package, and if you have the arules package loaded, you will want to preface this inspect with tm::inspect:

inspect(dtm[1:10, 1:10]) > <<DocumentTermMatrix (documents: 10, terms: 10)>>