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

13.4 AN APPLICATION OF LOGISTIC REGRESSION MODELING

Let us revisit the clothing_sales_training and clothing_sales_test data sets. This time, our goal is to determine whether or not customers have a store credit card, so our marketing team can send out advertisements to non‐holders, enticing them to sign up for a card. Our response variable in this case is binary: Yes, the customer has a card; or No, the customer does not. Since the response variable is binary, we will use logistic regression.

Our provisional logistic regression model will be

equationp^(creditcard)=exp(b0+b1(Days between Purchases)+b2(WebAccount))1+exp(b0+b1(Days between Purchases)+b2(WebAccount))--

The results of the regression of Credit Card on the two predictor variables are shown in Figure 13.1. The p‐values shown in the output tell us that both variables belong in the model. When we cross‐validate the results with the test data set, we obtain the results shown in Figure 13.2.

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