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

Plotting the autocorrelation function


The autocorrelation function, is very important if you want to find the interrelationship between time series using the lagged values. The acf function will plot the correlation between all pairs of data points with lagged values. The plot will have two horizontal blue dashed lines at -0.2 and 0.2, representing the upper and lower bounds. If auto-correlation coefficients are close to zero, this means that there is no relationship, so time series are also known as white noise.

Getting ready

You have already completed the previous recipes and familiar with time series.

How to do it...

Perform the following steps with R:

> sales = sample(400:10000, 72, replace= TRUE) 
> sales 
Output: 
 
 [1] 3304 7697 6715 3906 8963 9240 1423 5330 8298 7747 1686 2917 2004 4591 2213 1977 
[17] 1101 7624 2814 4002 8284 6016 5875 6936 1336 6090 4190 7437 1968 3070 4013 5186 
[33] 6560 7981 5496 8818 1991 3531 4624  895 5720 8481  826  435 6940 1723 9797 8261 
[49] 8811 4933...