Book Image

Machine Learning with R Cookbook

By : Yu-Wei, Chiu (David Chiu)
Book Image

Machine Learning with R Cookbook

By: Yu-Wei, Chiu (David Chiu)

Overview of this book

<p>The R language is a powerful open source functional programming language. At its core, R is a statistical programming language that provides impressive tools to analyze data and create high-level graphics.</p> <p>This book covers the basics of R by setting up a user-friendly programming environment and performing data ETL in R. Data exploration examples are provided that demonstrate how powerful data visualization and machine learning is in discovering hidden relationships. You will then dive into important machine learning topics, including data classification, regression, clustering, association rule mining, and dimension reduction.</p>
Table of Contents (21 chapters)
Machine Learning with R Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Resources for R and Machine Learning
Dataset – Survival of Passengers on the Titanic
Index

Applying the Poisson model for generalized linear regression


Generalized linear models allow response variables that have error distribution models other than a normal distribution (Gaussian). In this recipe, we demonstrate how to apply Poisson as a family object within glm with regard to count data.

Getting ready

The prerequisite of this task is to prepare the count data, with all the input data values as integers.

How to do it...

Perform the following steps to fit the generalized linear regression model with the Poisson model:

  1. Load the warpbreaks data, and use head to view the first few lines:

    > data(warpbreaks)
    > head(warpbreaks)
      breaks wool tension
    1     26    A       L
    2     30    A       L
    3     54    A       L
    4     25    A       L
    5     70    A       L
    6     52    A       L
    
  2. We apply Poisson as a family object for the independent variable, tension, and the dependent variable, breaks:

    > rs1 = glm(breaks ~ tension, data=warpbreaks, family="poisson")
    > summary(rs1)
    
    Call:
    glm...