Book Image

Mastering Predictive Analytics with R - Second Edition

By : James D. Miller, Rui Miguel Forte
Book Image

Mastering Predictive Analytics with R - Second Edition

By: James D. Miller, Rui Miguel Forte

Overview of this book

R offers a free and open source environment that is perfect for both learning and deploying predictive modeling solutions. With its constantly growing community and plethora of packages, R offers the functionality to deal with a truly vast array of problems. The book begins with a dedicated chapter on the language of models and the predictive modeling process. You will understand the learning curve and the process of tidying data. Each subsequent chapter tackles a particular type of model, such as neural networks, and focuses on the three important questions of how the model works, how to use R to train it, and how to measure and assess its performance using real-world datasets. How do you train models that can handle really large datasets? This book will also show you just that. Finally, you will tackle the really important topic of deep learning by implementing applications on word embedding and recurrent neural networks. By the end of this book, you will have explored and tested the most popular modeling techniques in use on real- world datasets and mastered a diverse range of techniques in predictive analytics using R.
Table of Contents (22 chapters)
Mastering Predictive Analytics with R Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
8
Dimensionality Reduction
Index

Modeling tweet topics


In machine learning and natural language processing, a topic model is a type of statistical model used to discover the abstract topics that occur in a collection of documents. A good example or use case to illustrate this concept is Twitter. Suppose we could analyze an individual's (or an organization's) tweets to discover any overriding trend. Let's look at a simple example.

If you have a Twitter account, you can perform this exercise pretty easily (you can then apply the same process to an archive of tweets you want to focus on and/or model). First, we need to create a tweet archive file.

Under Settings, you can submit a request to receive your tweets in an archive file. Once it's ready, you'll get an email with a link to download it:

And then save your file locally:

Now that we have a data source to work with, we can move the tweets into a list object (we'll call it x) and then convert that into an R data frame object (df1):

The tweets were first converted to a data frame...