Book Image

Regression Analysis with R

By : Giuseppe Ciaburro
Book Image

Regression Analysis with R

By: Giuseppe Ciaburro

Overview of this book

Regression analysis is a statistical process which enables prediction of relationships between variables. The predictions are based on the casual effect of one variable upon another. Regression techniques for modeling and analyzing are employed on large set of data in order to reveal hidden relationship among the variables. This book will give you a rundown explaining what regression analysis is, explaining you the process from scratch. The first few chapters give an understanding of what the different types of learning are – supervised and unsupervised, how these learnings differ from each other. We then move to covering the supervised learning in details covering the various aspects of regression analysis. The outline of chapters are arranged in a way that gives a feel of all the steps covered in a data science process – loading the training dataset, handling missing values, EDA on the dataset, transformations and feature engineering, model building, assessing the model fitting and performance, and finally making predictions on unseen datasets. Each chapter starts with explaining the theoretical concepts and once the reader gets comfortable with the theory, we move to the practical examples to support the understanding. The practical examples are illustrated using R code including the different packages in R such as R Stats, Caret and so on. Each chapter is a mix of theory and practical examples. By the end of this book you will know all the concepts and pain-points related to regression analysis, and you will be able to implement your learning in your projects.
Table of Contents (15 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Count data model


Poisson regression is a form of regression used to model the count of data in contingency tables. For example, counting the number of births or the number of wins in a series of soccer matches. Poisson regression assumes that the response variable Y has a Poisson distribution, and that the logarithm of its expected value can be modelled by a linear combination of unknown parameters. Poisson regression is sometimes also known as a log-linear model, especially when it is used to model contingency tables.

Poisson distributions

A distribution tells us how measures of a certain variable are distributed among the various possible values. Each distribution is characterized by an average value and a variance, which adjusts the uncertainty of the measurements obtained. Poisson's distribution, also known as rare event law, is a very useful type of distribution when dealing with extremely rare events, which occur with a well-defined temporal mean. It is an approximation of the binomial...