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. Explain the difference between model evaluation and model validation.
  2. What does a contingency table consist of?
  3. Show that GT = TPN + TPP and that TAP = GT − TAN.
  4. Show that Error Rate = 1 − Accuracy.
  5. What do sensitivity and specificity measure?
  6. Explain the Method for Model Evaluation.
  7. Why did we choose the All Negative model as a baseline to calibrate the accuracy of Model 1, rather than the All Positive model?
  8. When error costs are unequal, what is the most important evaluation measure for the purpose of model selection?
  9. Explain how a naïve analyst would erroneously prefer Model 1 to Model 2.
  10. For the All Positive and All Negative models, calculate the evaluation metrics from Table 7.11.

WORKING WITH THE DATA

For Exercises 1122, work with the clothing_data_driven_training and clothing_data_driven_test data sets. Use R to solve each problem.

  1. Using the training data set, create a...