This guide for practicing statisticians, data scientists, and R users and programmers will teach the essentials of preprocessing: data leveraging the R programming language to easily and quickly turn noisy data into usable pieces of information. Data wrangling, which is also commonly referred to as data munging, transformation, manipulation, janitor work, etc., can be a painstakingly laborious process. Roughly 80% of data analysis is spent on cleaning and preparing data; however, being a prerequisite to the rest of the data analysis workflow (visualization, analysis, reporting), it is essential that one become fluent and efficient in data wrangling techniques.

This book will guide the user through the data wrangling process via a step-by-step tutorial approach and provide a solid foundation for working with data in R. The author's goal is to teach the user how to easily wrangle data in order to spend more time on understanding the content of the data. By the end of the book, the user will have learned:

How to work with different types of data such as numerics, characters, regular expressions, factors, and dates
The difference between different data structures and how to create, add additional components to, and subset each data structure
How to acquire and parse data from locations previously inaccessible
How to develop functions and use loop control structures to reduce code redundancy
How to use pipe operators to simplify code and make it more readable
How to reshape the layout of data and manipulate, summarize, and join data sets

Presents techniques that allow users to spend less time obtaining, cleaning, manipulating, and preprocessing data and more time visualizing, analyzing, and presenting data via a step-by-step tutorial approach Includes a wide range of programming activities, from understanding basic data objects in R to writing functions, applying loops, and webscraping Beneficial to all levels of R programmers: Beginner R programmers will gain a basic understanding of the functionality of R along with learning how to work with data using R, while intermediate and advanced R programmers will find the early chapters reiterating established knowledge and will learn newer and more efficient data wrangling techniques in the mid and later chapters Covers the most recent data wrangling packages: dplyr, tidyr, httr, stringr, lubridate, readr, rvest, magrittr, xlsx, readxl, and others Provides code examples and chapter exercises Includes supplementary material: sn.pub/extras

Autorentext
Brad Boehmke, Ph.D., is an Operations Research Analyst at Headquarters Air Force Materiel Command, Studies and Analyses Division. He is also Assistant Professor in the Operational Sciences Department at the Air Force Institute of Technology. Dr. Boehmke's research interests are in the areas of cost analysis, economic modeling, decision analysis, and developing applied modeling applications through the R statistical language.

Inhalt
Preface.- Introduction .- Working with Different Types of Data in R.- Managing Data Structures in R.- Importing, Scraping, and Exporting Data with R.- Creating Efficient & Readable Code in R.- Shaping & Transforming Your Data with R.