Programming Skills for Data Science: Start Writing Code to Wrangle, Analyze, and Visualize Data with R

385 Pages·1·16.123 MB·English

by  Michael K. Freeman, Joel Ross

ptg27139148
Programming Skills
for Data Science
ptg27139148
The Pearson Addison-Wesley
Data and Analytics Series
Visit informit.com/awdataseries for a complete list of available publications.
ptg27139148
T he Pearson Addison-Wesley Data and Analytics Series provides readers with
practical knowledge for solving problems and answering questions with data.
Titles in this series primarily focus on three areas:
1. Infrastructure: how to store, move, and manage data
2. Algorithms: how to mine intelligence or make predictions based on data
3. V isualizations: how to represent data and insights in a meaningful and
compelling way
The series aims to tie all three of these areas together to help the reader build
end-to-end systems for fighting spam; making recommendations; building
personalization; detecting trends, patterns, or problems; and gaining insight
from the data exhaust of systems and user interactions.
(cid:98)
Make sure to connect with us!
informit.com/socialconnect
Programming Skills
for Data Science
Start Writing Code to
Wrangle, Analyze, and
Visualize Data with R
ptg27139148
Michael Freeman
Joel Ross
Boston • Columbus • New York • San Francisco • Amsterdam • Cape Town
Dubai • London • Madrid • Milan • Munich • Paris • Montreal • Toronto • Delhi • Mexico City
São Paulo • Sydney • Hong Kong • Seoul • Singapore • Taipei • Tokyo
Manyofthedesignationsusedbymanufacturersandsellerstodistinguishtheirproductsareclaimedas
trademarks.Wherethosedesignationsappearinthisbook,andthepublisherwasawareofatrademark
claim,thedesignationshavebeenprintedwithinitialcapitallettersorinallcapitals.
Theauthorsandpublisherhavetakencareinthepreparationofthisbook,butmakenoexpressedorimplied
warrantyofanykindandassumenoresponsibilityforerrorsoromissions.Noliabilityisassumedfor
incidentalorconsequentialdamagesinconnectionwithorarisingoutoftheuseoftheinformationor
ptg27139148
programscontainedherein.
Forinformationaboutbuyingthistitleinbulkquantities,orforspecialsalesopportunities(whichmayinclude
electronicversions;customcoverdesigns;andcontentparticulartoyourbusiness,traininggoals,marketing
focus,orbrandinginterests),pleasecontactourcorporatesalesdepartment
[email protected][phone].
Forgovernmentsalesinquiries,[email protected].
ForquestionsaboutsalesoutsidetheU.S.,[email protected].
VisitusontheWeb:informit.com/aw
LibraryofCongressControlNumber:2018953978
Copyright©2019PearsonEducation,Inc.
Allrightsreserved.Thispublicationisprotectedbycopyright,andpermissionmustbeobtainedfromthe
publisherpriortoanyprohibitedreproduction,storageinaretrievalsystem,ortransmissioninanyformorby
anymeans,electronic,mechanical,photocopying,recording,orlikewise.Forinformationregarding
permissions,requestformsandtheappropriatecontactswithinthePearsonEducationGlobalRights&
PermissionsDepartment,pleasevisitwww.pearsoned.com/permissions/.
ISBN-13:978-0-13-513310-1
ISBN-10:0-13-513310-6
1 18
(cid:118)
Toourstudentswhochallengedustodevelopbetterresources,and
ourfamilieswhosupportedusintheprocess.
(cid:118)
ptg27139148
This page intentionally left blank
ptg27139148
Contents
Foreword xi
Preface xiii
Acknowledgments xvii
AbouttheAuthors xix
I: GettingStarted 1
1 SettingUpYourComputer 3
1.1 SettingupCommandLineTools 4
1.2 Installinggit 5
1.3 CreatingaGitHubAccount 6
1.4 SelectingaTextEditor 6
1.5 DownloadingtheRLanguage 7
1.6 DownloadingRStudio 8
2 UsingtheCommandLine 9
2.1 AccessingtheCommandLine 9
ptg27139148
2.2 NavigatingtheFileSystem 11
2.3 ManagingFiles 15
2.4 DealingwithErrors 18
2.5 DirectingOutput 20
2.6 NetworkingCommands 20
II: ManagingProjects 25
3 VersionControlwithgitandGitHub 27
3.1 WhatIsgit? 27
3.2 ConfigurationandProjectSetup 30
3.3 TrackingProjectChanges 32
3.4 StoringProjectsonGitHub 36
3.5 AccessingProjectHistory 40
3.6 IgnoringFilesfromaProject 42
4 UsingMarkdownforDocumentation 45
4.1 WritingMarkdown 45
4.2 RenderingMarkdown 48
viii Contents
III: FoundationalRSkills 51
5 IntroductiontoR 53
5.1 ProgrammingwithR 53
5.2 RunningRCode 54
5.3 IncludingComments 58
5.4 DefiningVariables 58
5.5 GettingHelp 63
6 Functions 69
6.1 WhatIsaFunction? 69
6.2 Built-inRFunctions 71
6.3 LoadingFunctions 73
6.4 WritingFunctions 75
6.5 UsingConditionalStatements 79
7 Vectors 81
7.1 WhatIsaVector? 81
7.2 VectorizedOperations 83
ptg27139148
7.3 VectorIndices 88
7.4 VectorFiltering 90
7.5 ModifyingVectors 92
8 Lists 95
8.1 WhatIsaList? 95
8.2 CreatingLists 96
8.3 AccessingListElements 97
8.4 ModifyingLists 100
8.5 ApplyingFunctionstoListswithlapply() 102
IV: DataWrangling 105
9 UnderstandingData 107
9.1 TheDataGenerationProcess 107
9.2 FindingData 108
9.3 TypesofData 110
9.4 InterpretingData 112
9.5 UsingDatatoAnswerQuestions 116
Contents ix
10 DataFrames 119
10.1 WhatIsaDataFrame? 119
10.2 WorkingwithDataFrames 120
10.3 WorkingwithCSVData 124
11 ManipulatingDatawithdplyr 131
11.1 AGrammarofDataManipulation 131
11.2 CoredplyrFunctions 132
11.3 PerformingSequentialOperations 139
11.4 AnalyzingDataFramesbyGroup 142
11.5 JoiningDataFramesTogether 144
11.6 dplyrinAction:AnalyzingFlightData 148
12 ReshapingDatawithtidyr 155
12.1 WhatIs“Tidy”Data? 155
12.2 FromColumnstoRows:gather() 157
12.3 FromRowstoColumns:spread() 158
12.4 tidyrinAction:ExploringEducationalStatistics 160
ptg27139148
13 AccessingDatabases 167
13.1 AnOverviewofRelationalDatabases 167
13.2 ATasteofSQL 171
13.3 AccessingaDatabasefromR 175
14 AccessingWebAPIs 181
14.1 WhatIsaWebAPI? 181
14.2 RESTfulRequests 182
14.3 AccessingWebAPIsfromR 189
14.4 ProcessingJSONData 191
14.5 APIsinAction:FindingCubanFoodinSeattle 197
V: DataVisualization 205
15 DesigningDataVisualizations 207
15.1 ThePurposeofVisualization 207
15.2 SelectingVisualLayouts 209
15.3 ChoosingEffectiveGraphicalEncodings 220
15.4 ExpressiveDataDisplays 227
15.5 EnhancingAesthetics 229