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

13.2 LINEAR REGRESSION AS A GENERAL LINEAR MODEL

When the response variable has a Normal distribution at each set of given predictor variable values, then we are back in the realm of linear regression. In this realm, the link function is simply the identity function, where

equationg(μ)=μ--

Setting equal to g(μ) using this identity link gives us = g(μ) = μ.

Once we have a functional relationship between and μ, we can work backwards to obtain the final form of the regression model by expanding our abbreviated notation. Doing so gives us the population equation for linear regression:

equationy=β0+β1x1+β2x2++βpxp+ε--

from which we can obtain the descriptive form

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

which we worked with in Chapter 11.