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

13.6 AN APPLICATION OF POISSON REGRESSION MODELING

We will use the churn data set to build a model that estimates the number of customer service calls based on whether a customer churned. Our response variable is an integer‐valued variable, which is why we use Poisson regression instead of linear regression for this estimation.

The structure of our Poisson regression model will be

equationCustServ ^Calls=exp(b0+b1(Churn))--

The result of the regression analysis is given in Figure 13.5. Using the coefficients given above, we can build the Poisson regression model

equationCustServ ^Calls=exp(0.3714+0.4305(Churn=True))--
No alt text required.

Figure 13.5 Python Poisson regression results for predicting number of customer service calls.

Now, how do we interpret the Poisson regression coefficients? When used as the exponent of e, the regression coefficient describes the estimated multiplicative change in the response variable when the coefficient's predictor variable increases by one. In our case...