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

Scale of features


Data scaling is a preprocessing technique usually employed before feature selection and classification. Many artificial intelligence-based systems use features that are generated by many different feature extraction algorithms, with  different kinds of sources. These features may have different dynamic ranges. Popular distance measures, for example the Euclidean distance, implicitly assign more weighting to features with large ranges than those with small ranges. Feature scaling is thus required to approximately equalize ranges of the features and make them have approximately the same effect in the computation of similarity.

In addition, in several data mining applications with huge numbers of features with large dynamic ranges, feature scaling may improve the performance of the fitting model. However, the appropriate choice of these techniques is an important issue, since applying scaling on the input could change the structure of data and thereby affect the outcome of...