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

Imputing missing values


After detecting the number of missing values within each attribute, we have to impute them since they might have a significant effect on the conclusions that can be drawn from the data.

Getting ready

This recipe will require mydata to be loaded in the R session and have the previous recipe completed.

How to do it...

Perform the following steps to impute the missing values:

  1. List the Ozone attribute:
        > mydata$Ozone
        Output
       [1] 41 36 12 18 NA 28 23 19 8 NA 7 16 11 14 18 14 34 6 30 11
      [21] 1 11 4 32 NA NA NA 23 45 115 37 NA NA NA NA NA NA 29 NA 71
      [41] 39 NA NA 23 NA NA 21 37 20 12 13 NA NA NA NA NA NA NA NA NA
      [61] NA 135 49 32 NA 64 40 77 97 97 85 NA 10 27 NA 7 48 35 61 79
      [81] 63 16 NA NA 80 108 20 52 82 50 64 59 39 9 16 78 35 66 122 89
      [101] 110 NA NA 44 28 65 NA 22 59 23 31 44 21 9 NA 45 168 73 NA 76
      [121] 118 84 85 96 78 73 91 47 32 20 23 21 24 44 21 28 9 13 46 18
      [141] 13 24 16 13 23 36 7 14 30 NA 14...