Book Image

Data Science Using Python and R

By : Chantal D. Larose, Daniel T. Larose
Book Image

Data Science Using Python and R

By: Chantal D. Larose, Daniel T. Larose

Overview of this book

Data science is hot. Bloomberg named a data scientist as the ‘hottest job in America’. Python and R are the top two open-source data science tools using which you can produce hands-on solutions to real-world business problems, using state-of-the-art techniques. Each chapter in the book presents step-by-step instructions and walkthroughs for solving data science problems using Python and R. You’ll learn how to prepare data, perform exploratory data analysis, and prepare to model the data. As you progress, you’ll explore what are decision trees and how to use them. You’ll also learn about model evaluation, misclassification costs, naïve Bayes classification, and neural networks. The later chapters provide comprehensive information about clustering, regression modeling, dimension reduction, and association rules mining. The book also throws light on exciting new topics, such as random forests and general linear models. The book emphasizes data-driven error costs to enhance profitability, which avoids the common pitfalls that may cost a company millions of dollars. By the end of this book, you’ll have enough knowledge and confidence to start providing solutions to data science problems using R and Python.
Table of Contents (20 chapters)
Free Chapter
1
ABOUT THE AUTHORS
17
INDEX
18
END USER LICENSE AGREEMENT

11.2 DESCRIPTIVE REGRESSION MODELING

The usual multiple regression model is a parametric model, defined by the following equation:

equationy=β0+β1x1+β2x2++βpxp+ε--

where the x's represent the predictor variables, and the β's represent the unknown model parameters, whose values are estimated using the data.1 Now, estimating model parameters using sample data represents classical statistical inference. The Data Science Methodology outlined in Chapter 1, however, employs cross‐validation rather than classical statistical inference to validate model results. Thus, in this book, we will bypass the parametric regression equation above, in favor of a descriptive approach to regression modeling, using the following regression equation:

equationy^=b0+b1x1+b2x2++bpxp--

In this regression equation, imagesy^--y, the b's represent the known values of the regression coefficients, and the x's represent the predictor variables.