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

4.4 HISTOGRAMS WITH RESPONSE OVERLAY

A histogram is a graphical representation of a frequency distribution for a numerical variable. Figure 4.6 shows a histogram of the age variable with an overlay of response. Most customers range from, say, mid‐20s to about 60 years of age. So (non‐normalized) histograms are useful for seeing the distribution of the values of a numeric variable.

Image described by caption and surrounding text.

Figure 4.6 Histogram from R of age with response overlay.

Again, however, it is somewhat difficult to ascertain any pattern in the response proportions. To better clarify these response proportions, we turn to a normalized histogram with response overlay, shown in Figure 4.7. Suddenly the response pattern becomes crystal clear. Customer response starts off high for 20‐year olds, gradually decreases, flattening out low for 30–60‐year olds, and rising sharply again for those over 60. So, the normalized histogram allows us to better distinguish these response patterns...