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

Exponential smoothing


In moving averages, all observations are weighted equally, whereas in exponential smoothing, the weights are assigned in exponentially decreasing order as the observation gets older. This ensures that the recent or latest observations are given more weightage as compared to older observations and thus can forecast on the basis of recent observations.

Getting ready

You have completed the preceding recipes and the AirPassengers dataset is available or loaded in R.

How to do it...

Perform the following steps with R:

> library(forecast) 
> t = ets(AirPassengers) 
> t 
Output: 
 
ETS(M,Ad,M)  
 
Call: 
 ets(y = AirPassengers)  
 
  Smoothing parameters: 
    alpha = 0.7322  
    beta  = 0.0188  
    gamma = 1e-04  
    phi   = 0.98  
 
  Initial states: 
    l = 120.9759  
    b = 1.8015  
    s=0.8929 0.7984 0.9211 1.0604 1.2228 1.2324 
           1.1107 0.9807 0.9807 1.0106 0.8843 0.9051 
 
  sigma:  0.0368 
 
     AIC     AICc      BIC  
1395.092 1400.564 1448.548...