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

Support Vector Regression


SVR is based on the same principles as the Support Vector Machine (SVM). In fact, SVR is the adapted form of SVM when the dependent variable is numeric rather than categorical. One of the main advantages of using SVR is that it is a nonparametric technique.

To build the model, the SVR technique uses the kernel functions. The commonly used kernel functions are:

  • Linear
  • Polynomial
  • Sigmoid
  • Radial base

This technique allows the fitting of a nonlinear model without changing the explanatory variables, helping to interpret the resulting pattern better.

In the SVR, we do not have to worry about the prediction as long as the error (ε) remains above a certain value. This method is called the maximal margin principle. The maximal margin allows SVR to be seen as a convex optimization problem.

Regression can also be penalized using a cost parameter, which becomes useful in avoiding excess adaptation. SVR is a useful technique that provides the user with a great flexibility in distributing...