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

9.6 AN APPLICATION OF A NEURAL NETWORK MODEL

We next turn to an example of a neural network model using a subset of the Framingham Heart Study data.2The data set, Framingham_training, contains information on three variables for 7953 patients. Sex is a binary predictor with 1 = Male and 2 = Female. Age is a continuous predictor. The target variable is Death, with values 0 = survival and 1 = death.

Clues to the relationship between the predictors and the target are obtained through exploratory data analysis, namely through Figures 9.5 and 9.6, and Tables 9.2 and 9.3. The histograms in Figures 9.5 and 9.6 show that, as Age increases, the proportion of Death increases. Tables 9.2 and 9.3 show that a larger proportion of males died, compared to females. Thus, these interrelationships should be reflected in our neural network model results.

Histogram from R of Age with death overlay displaying stacked bars with shades representing death 0 (light) and 1 (dark).

Figure 9.5 Histogram from R of Age, with Death overlay.

Normalized histogram from R of Age, with Death overlay depicting staked bars in discrete shades representing 0 (light) and 1 (dark).

Figure 9.6 Normalized histogram from R of Age, with Death overlay.

TABLE 9.2 Contingency...