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

12.4 PRINCIPAL COMPONENTS ANALYSIS

So, now that we have identified the multicollinearity among our predictors, what do we do now?

One solution is to apply principal components analysis. Principal components analysis (PCA) seeks to account for the correlation structure of a set of predictor variables, using a smaller set of uncorrelated linear combinations of these variables, called components. The total variability produced by the complete set of m predictors can often be mostly accounted for by a smaller set of k < m components. This means that there is almost as much information in the k components as there is in the original m variables. In addition, the k components are uncorrelated with each other, unlike the original correlated predictors. If desired, the analyst can then replace the original m variables with the k < m components, so that the working data set now consists of n records on k components, rather than n records on m predictors. This...