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

14.3 SUPPORT, CONFIDENCE, AND LIFT

Measures of goodness of an association rule include support, confidence, and lift. The support for a particular association rule A ⇒ B is the proportion of transactions in D that contain both A and B. That is,

equationsupport=P(AB)=number of transactions containing bothAandBtotal number of transactions--

The confidence of the association rule A ⇒ B is a measure of the accuracy of the rule, as determined by the percentage of transactions in D containing A that also contain B. In other words,

equationconfidence=P(B|A)=P(AB)P(A)=number of transactions containing bothAandBnumber of transactions containingA--

In the language of probability, confidence represents the conditional probability of B, given A.

For example, consider the association rule, “If buy squash, then buy beans,” where A represents squash and B represents beans...