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

Fitting a robust linear regression model with rlm


An outlier in the dataset will move the regression line away from the mainstream. Apart from removing it, we can apply a robust linear regression to fit datasets containing outliers. In this recipe, we will introduce how to apply rlm to perform robust linear regression to datasets containing outliers.

Getting ready

Prepare the dataset that contains an outlier that may move the regression line away from the mainstream. Here, we use the Quartet dataset loaded from the previous recipe.

How to do it...

Perform the following steps to fit the robust linear regression model with rlm:

  1. Generate a scatter plot of the x variable against y3:
        > plot(Quartet$x, Quartet$y3)  

Scatter plot of variables x and y3

  1. Next, you should import the MASS library first. Then, you can apply the rlm function to fit the model, and visualize the fitted line with the abline function:
        > library(MASS)
        > lmfit = rlm(Quartet$y3~Quartet$x)
        &gt...