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

EXERCISES

CLARIFYING THE CONCEPTS

  1. What do we mean by high dimensionality in data science?
  2. Why do we need dimension reduction methods?
  3. What does principal components replace the original set of m predictors with?
  4. Which principal component accounts for the most variability?
  5. Which of the other principal components is correlated with the first principal component?
  6. Why do we use rotation?
  7. Explain the eigenvalue criterion?
  8. What is the proportion of variance explained criterion?
  9. True or false: It is not necessary to perform validation of the principal components.
  10. When we use the principal components as predictors in a regression model, what value do the VIFs take? What does this indicate?

WORKING WITH THE DATA

For the following exercises, work with the clothing_store_PCA_training and clothing_store_PCA_test data sets. Use either Python or R to solve each problem.

  1. Standardize or normalize the predictors.
  2. Construct the correlation matrix for the predictor variables Purchase Visits, Days...