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

Visualizing a generalized additive model


In this recipe, we demonstrate how to add a gam fitted regression line to a scatter plot. In addition, we visualize the gam fit using the plot function.

Getting ready

Complete the previous recipe by assigning a gam fitted model to the fit variable.

How to do it...

Perform the following steps to visualize the generalized additive model:

  1. Generate a scatter plot using the nox and dis variables:
        > plot(nox, dis)  

Scatter plot of variable nox against dis

  1. Add the regression to the scatter plot:
        > x = seq(0, 1, length = 500)
        > y = predict(fit, data.frame(nox = x))
        > lines(x, y, col = "red", lwd = 2) 

Fitted regression of gam on a scatter plot

  1. Alternatively, you can plot the fitted model using the plot function:
        > plot(fit)  

Plot of fitted gam

How it works...

To visualize the fitted regression, we first generate a scatter plot using the dis and nox variables. Then, we generate the sequence of x-axis, and respond y...