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

Diagnosing a generalized additive model


GAM also provides diagnostic information about the fitting procedure and results of the generalized additive model. In this recipe, we demonstrate how to plot diagnostic plots through the gam.check function.

Getting ready

Ensure that the previous recipe is completed with the gam fitted model assigned to the fit variable.

How to do it...

Perform the following step to diagnose the generalized additive model:

  1. Generate the diagnostic plot using gam.check on the fitted model:
        > gam.check(fit)
        Output:
        Method: GCV Optimizer: magic
        Smoothing parameter selection converged after 7 iterations.
        The RMS GCV score gradient at convergence was 8.79622e-06 .
        The Hessian was positive definite.
        The estimated model rank was 10 (maximum possible: 10)
        Model rank = 10 / 10 

        Basis dimension (k) checking results. Low p-value (k-index<1) may
        indicate that k is too low, especially if edf is close...