Book Image

Machine Learning with R Cookbook, Second Edition - Second Edition

By : Yu-Wei, Chiu (David Chiu)
Book Image

Machine Learning with R Cookbook, Second Edition - Second Edition

By: Yu-Wei, Chiu (David Chiu)

Overview of this book

Big data has become a popular buzzword across many industries. An increasing number of people have been exposed to the term and are looking at how to leverage big data in their own businesses, to improve sales and profitability. However, collecting, aggregating, and visualizing data is just one part of the equation. Being able to extract useful information from data is another task, and a much more challenging one. Machine Learning with R Cookbook, Second Edition uses a practical approach to teach you how to perform machine learning with R. Each chapter is divided into several simple recipes. Through the step-by-step instructions provided in each recipe, you will be able to construct a predictive model by using a variety of machine learning packages. In this book, you will first learn to set up the R environment and use simple R commands to explore data. The next topic covers how to perform statistical analysis with machine learning analysis and assess created models, covered in detail later on in the book. You'll also learn how to integrate R and Hadoop to create a big data analysis platform. The detailed illustrations provide all the information required to start applying machine learning to individual projects. With Machine Learning with R Cookbook, machine learning has never been easier.
Table of Contents (21 chapters)
Title Page
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface

Viewing the summary of survival analysis


Once we have the survfit object, we can see the summary of it to get some insights.

Getting ready

You need to have completed the previous recipe and have the sfit object from cancer dataset.

How to do it...

Perform the following steps to view the summary:

> sfit <- survfit(Surv(time, status)~sex, data=cancer)
> sfit
Output
Call: survfit(formula = Surv(time, status) ~ sex, data = cancer)

n events median 0.95LCL 0.95UCL
sex=1 138 112 270 212 310
sex=2 90 53 426 348 550


> summary(sfit)
The following are a few lines from the output of the summary command:
Call: survfit(formula = s ~ sex, data = cancer)

 sex=1 
 time n.risk n.event survival std.err lower 95% CI upper 95% CI
 11 138 3 0.9783 0.0124 0.9542 1.000
 12 135 1 0.9710 0.0143 0.9434 0.999
 13 134 2 0.9565 0.0174 0.9231 0.991
 15 132 1 0.9493 0.0187 0.9134 0.987
 26 131 1 0.9420 0.0199 0.9038 0.982

How it works...

The surfit function shows details for different genders. If we look at the...