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

Transposing a dataframe

You will sometimes be given a format that contains data that is arranged vertically and you want to flip it so that the variables are arranged horizontally. You will also hear this referred to as long format versus wide format. Most predictive analytics packages are set up to use long format, but there are often cases in which you want to switch rows with columns. Perhaps data is being input as a set of key pairs and you want to be able to map them to features for an individual entity. Also, this may be necessary with some time series data in which the data which comes in as long format needs to be reformatted so that the time periods appear horizontally.

Here is a data frame that consists of sales for each member for each month in the first quarter. We will use the text=' option of the read.table() function to read table data that we have pasted directly into the code. For example, this is from data that has been pasted directly from an Excel spreadsheet: