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
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Characterizing the clusters by their mean values


Another way to look at the clusters is by looking directly at their mean values. We can do this directly by using SQL:

  • First, look at any variables which have normalized values >1 or < -1, or high the highest absolute value for that variable. That will give you some clues on how to begin to classify the clusters.
  • Also look at the magnitude and the signs of the coefficients. Coefficients with large absolute values can indicate an important influence of the variable on that particular cluster. Variables with opposite signs are important in terms of characterizing or naming the clusters.
        tmp_agg <- SparkR::sql("SELECT prediction, mean(age),
        mean(triceps),      
        mean(pregnant),mean(pressure),mean(insulin),
        mean(glucose),
        mean(pedigree) from fitted_tbl group by 1") 
        head(tmp_agg) 

Scanning through the five clusters produced, you might categorize Cluster 2 as a group consisting of younger people...