www.it-ebooks.info www.it-ebooks.info BEGINNING R INTRODUCTION xxi CHAP TE R 1 Introducing R: What It Is and How to Get It 1 CHAPTER 2 Starting Out: Becoming Familiar with R 25 CHAPTER 3 Starting Out: Working With Objects 65 CHAPTER 4 Data: Descriptive Statistics andTabulation 107 CHAPTER 5 Data: Distribution 151 CHAPTER 6 Simple Hypothesis Testing 181 CHAPTER 7 Introduction to Graphical Analysis 215 CHAPTER 8 Formula Notation and Complex Statistics 263 CHAPTER 9 Manipulating Data and Extracting Components 295 CHAPTER 10 Regression (Linear Modeling) 327 CHAPTER 11 More About Graphs 363 CHAPTER 12 Writing Your Own Scripts: Beginning to Program 415 APPENDIX Answers to Exercises 433 INDEX 461 www.it-ebooks.info www.it-ebooks.info BEGINNING R THE STATISTICAL PROGRAMMING LANGUAGE www.it-ebooks.info www.it-ebooks.info BEGINNING R THE STATISTICAL PROGRAMMING LANGUAGE Mark Gardener www.it-ebooks.info Beginning R: The Statistical Programming Language Published by John Wiley & Sons, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2012 by John Wiley & Sons, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-1-118-16430-3 ISBN: 978-1-118-22616-2 (ebk) ISBN: 978-1-118-23937-7 (ebk) ISBN: 978-1-118-26412-6 (ebk) Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. 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John Wiley & Sons, Inc., is not associated with any product or vendor mentioned in this book. www.it-ebooks.info It is much easier to be critical than to be correct. — Benjamin Disraeli www.it-ebooks.info EXECUTIVE EDITOR Carol Long PROJECT EDITOR Victoria Swider TECHNICAL EDITOR Richard Rowe PRODUCTION EDITOR Kathleen Wisor COPY EDITOR Kim Cofer EDITORIAL MANAGER Mary Beth Wakefield FREELANCER EDITORIAL MANAGER Rosemarie Graham ASSOCIATE DIRECTOR OF MARKETING David Mayhew MARKETING MANAGER Ashley Zurcher BUSINESS MANAGER Amy Knies PRODUCTION MANAGER Tim Tate VICE PRESIDENT AND EXECUTIVE GROUP PUBLISHER Richard Swadley VICE PRESIDENT AND EXECUTIVE PUBLISHER Neil Edde ASSOCIATE PUBLISHER Jim Minatel PROJECT COORDINATOR, COVER Katie Crocker COMPOSITOR Craig Woods, Happenstance Type-O-Rama PROOFREADER James Saturnio, Word One INDEXER John Sleeva COVER DESIGNER LeAndra Young COVER IMAGE © iStock / Mark Wragg CREDITS www.it-ebooks.info [...]... easily locate it in the download file Once at the site, simply locate the book’s title (either by using the Search box or by using one of the title lists) and click the Download Code link on the book’s detail page to obtain all the source code for the book xxv www.it-ebooks.info introduction There will only be one file to download and it is called Beginning. RData This one file contains all the example datasets... Throughout the text, the use of these commands is illustrated, which is indeed the point of the book Where a command is illustrated in its basic form, you will see a fixed width font to mimic the R display like so: help.start() When the use of a particular command is illustrated, you will see the user-typed input illustrated by beginning the lines with the > character, which mimics the cursor line in the. .. an introductory book such as this Rather, the aim is to become familiar with the language of R and to carry out some of the more commonly used statistical methods In this way, you can strike out on your own and explore the full potential of R for yourself So, the focus is on the operation of R itself Along the way you learn how to carry out a range of commonly used statistical methods, including analysis... symbol represent the output from R (but look out for typed lines that are long and spread over more than one line), so in the following example the first line was typed by the user and the second line is the result: > data1 [1] 3 5 7 5 3 2 6 8 5 6 9 xxiv www.it-ebooks.info introduction tRy it out The Try It Out is an exercise you should work through, following the text in the book 1 2 3 They usually... is a computer program and statistical programming language/ environment It allows a wide range of analytical methods to be used and produces presentation-quality graphics This book covers the language of R, and leads you toward a better understanding of how to get R to do the things you need There is less emphasis on the actual statistical tests; indeed, R is so flexible that the list of tests www.it-ebooks.info... scripts you need for the whole book Once you have the file on your computer you can load it into R by one of several methods: ➤➤ For Windows or Mac you can drag the Beginning. RData file icon onto the R program icon; this will open R if it is not already running and load the data If R is already open, the data will be appended to anything you already have in R; otherwise only the data in the file will be... don’t spot “your” error on the Book Errata page, go to www.wrox.com/contact/techsupport shtml and complete the form there to send us the error you have found We’ll check the information and, if appropriate, post a message to the book’s errata page and fix the problem in subsequent editions of the book p2p wRox com For author and peer discussion, join the P2P forums at p2p.wrox.com The forums are a web-based... another you can take your work with you R handles complex statistical approaches as easily as more simple ones Therefore once you know the basics of the R language, you can tackle complex analyses as easily as simple ones (as usual it is the interpretation of results that can be the really hard bit) getting the hang oF R R is unlike most current computer programs in that you must type commands into the. .. help you get the most from the text and keep track of what’s happening, we’ve used a number of conventions throughout the book The commands you need to type into R and the output you get from R are shown in a monospace font Each example that shows lines that are typed by the user begins with the > symbol, which mimics the R cursor like so: > help() Lines that begin with something other than the > symbol... Getting the Hang of R  ❘  3 Lines of text resulting from your actions are shown without the cursor character, once again mimicking the output that you would see from R itself: > data1 [1] 3 5 7 5 3 2 6 8 5 6 9 So, in the preceding example the first line was typed by the user and resulted in the output shown in the second line Keep these conventions in mind as you are reading this chapter and they will . LANGUAGE www.it-ebooks.info www.it-ebooks.info BEGINNING R THE STATISTICAL PROGRAMMING LANGUAGE Mark Gardener www.it-ebooks.info Beginning R: The Statistical Programming Language Published. Scripts: Beginning to Program 415 APPENDIX Answers to Exercises 433 INDEX 461 www.it-ebooks.info www.it-ebooks.info BEGINNING R THE STATISTICAL PROGRAMMING LANGUAGE www.it-ebooks.info www.it-ebooks.info BEGINNING R THE