part a: r intro - universiti teknologi malaysia · 2018. 10. 13. · workshop: getting started with...

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Workshop:Getting Startedwith R.UTM14Oct2018.©Dr.NorhaizaAhmad

14 October 2018 Dr. Norhaiza Ahmad

Department of Mathematical SciencesFaculty of Science

Universiti Teknologi Malaysia

http://science.utm.my/norhaiza/

Getting Started with

for newbies

PART A: R INTRO



1. GotoDesktop2. ClickFolder:MathematicsSoftwareor

MathSoftware3. ClickFolder:R4. TherearethreeRapplications:

i. Ri3863.4.0ii. Rx643.4.0iii. RStudio

2

StartyourRSessioninthisMathLab!

Chooseanyofthesetwoversions

OtherwisegototheSTARTbuttonandsearchforRi386



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StartyourRSession!ExampleofanRSession



WorkshopSchedulePART ITEM DETAILS

PARTA Introduction AboutR.Anatomy ofR.DownloadRbase .BasicRSyntax.Rinterface

PARTB CoreofR R functions (in-built), RPackages.SearchHelpfunctions .InstallPackage.LoadPackage.

PART C Working inRStudio

PARTD Data Structure TypesofDataStructure.CheckandChangeDataStructure

PARTE Reading/ImportData ReadData format.Readfrominbuiltdataset.Importffrom .txt,.xls.ManualEntry

PARTF Basic StatisticalAnalysis Practise onsamplet-test,simplelinearregression

Practice oninstalling, running codes,plots



Outline

PARTA:INTRO1. AboutR2. AnatomyofR:FunctionsandPackages3. Downloading&InstallingR(base)4. UnderstandingtheRSyntax

Run&ExecuteCommandsObjectAssignmentSaving&Quitting

5. InterfaceoptionsforR

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AboutR

• A computer language, with orientation towards statistical applications

• Open-sourced software - non-commercialPrinciple: open exchange, publicly accessible Community-oriented software

• Origin in academics:solid foundation of core statistical and numerical algorithms and continues to grow to this end.



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OriginsofR

RisadialectfromaprogramminglanguagecalledS.S(languagedev.1976)—>SPlus(commercialsoftwarelicense1993)—>

Rsoftware(dev.1991- Rversion1.0.0in2000)

• S – developed about 40 years ago for research in telecommunication industry

https://www.r-project.org/conferences/useR-2006/Slides/Chambers.pdf

Commercialised(1993)

Version1(2000)

RossIhaka Robert Gentleman

R - created by two statisticians from University of Auckland



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WhyR?

FREE

LargeCommunityofRUsers

GrowsintandemwithDevelopmentinStatistics

WhyyoushouldlearnR?

Economicsustainability

Applicationcodes- latestresearchworkarelikelytobeavailabletouse.

Helpavailable:

Extensivehelpdocumentationinsystem

Justask!OrBrowseinarchiveQ&A



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BooksonR

ISBN978-0-387-09418-2ISBN-13:978-1420079333

AndPlentyofonlineresources!



Outline




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HowRworks:AnatomyofR

• R has many codes for many inbuilt functions, datasets & Help documentations

• These are contained in ‘Packages’ developed by the R-team and the community



Package‘base’

Containsvarious:

• Functions• Datasets• Help

Manymorepackageswithdifferentcapabilities!

Package‘stats’

Containsvarious:


…..

Package‘ggplot2’

Containsvarious:



Examples of ‘Packages’ in R

BasePackage• Corepackage• AutomaticallyinstalledwhenyoudownloadR

gglot2 Package• FancyDataVisualization

stats Package• Generalstatisticalapplications



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• R Packages are stored in certain Repositories:


Package‘base’

Containsvarious:


CRAN

ROfficial/Default

….. Manyotherpackages

Bioconductor

Rspecifictobioinformatics

GitHubOtherrepository:NotRbutRepository formanyopensourcedprojects

Package‘…’

Containsvarious:



Rforge

Includedevelopmentversionsofpackages

Package‘…’

Containsvarious:





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\

Whenyoudownloadandinstall- youwillbeautomaticallydownloadingandinstalling:

Rbase andselectedpackages(fromCRAN).

RBase

SelectedPackages

Add-OnPackages

PackagesinR=BRAINofR.


Otherpackagescanbeaddedonwhenrequired!



Outline


Run&ExecuteCommandsObjectAssignmentsSaving&Quitting


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16

HowtodownloadR?http://www.r-project.org/



DownloadingR

• Internetconnection• Seedocumentstepbystepprocedure onhowtodownloadR

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PointstoNote

• WhenyoudownloadandinstallR,youaredownloadingandinstallingbaseRandselectedpackages.

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OnceRdownloadiscomplete:§ anRIconwillappearonyourdesktop.



Outline




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RHowtoRun&ExecuteRcommands?

Method1

R-CONSOLE R-SCRIPT

Method2

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HowtoRuncommandsinR:Method1:RConsole

• DisplayedatthebeginningofanRsession• ComputationsareperformedonanRconsole

• Rcommandsaretypedandevaluatedhere.

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HowtoRuncommandsinR:Method1:RConsole

AttheRprompt:-TypeyourRcommandshere!

Rprompt(>)

R-Ribbon

ChecktheRversiononyourPCRisupdated regularly.Notnecessarytoupdateversioneverytime

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> 6+3> 6-3> (22+ 18+35)/3> 31 %% 7

Rascalculator

• WriteyourRcommandsaftereachprompt• HitEnter toexecutecommand

• Otheroperators:+,-,*,/23



Example

SupposeyouwouldliketotakealoanamountofP atamonthlyinterestrateofi.TheloanistobepaidbackinnmonthlyinstallmentsofsizeM,. whereMisgivenby:

M = P i1− 1+ i( )−n"

#$$

%

&''

SaythattheloanamountisRM1500withaninterestrateof1%andthenumberofinstallmentpaymentstobemadeis10times.UseRassignmentstocalculatetheamountthatshouldbepaidpermonth.

Sol:RM158.37

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Example:RCode

> P=1500> i=0.01> n=10> denom=1-(1+i)^(-n)> (M=P*(i/denom))[1] 158.3731

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HandyTip

• Usetheupanddownarrowkeys-

TorecallpreviousRlinecommandsintheconsole

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MakingCommentsinR

• CommentlinesinRaredenotedby“#”• Anylinesthatiswrittenafter“#”willnotbereadasanRcommand

• Comment linesareusefulformakingnotation/notesinyourprogram

> 31 %% 7 #remainder after division of 31 by 7

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RHowtoRun&ExecuteRcommands?

Method1 Method2

R-CONSOLE R-SCRIPT

Method2

- Commandsareexecuted- Likearoughpaper- Notconvenientforcode

storage

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Scriptwindow

Ascriptfile:filewhereyoucantypeyourcommandsandrunthemontheconsoleatyourownconvenience.

Itissimilartoanotepad/textfile!

Atconsole,click File- New

HowtoRuncommandsinR:Method2:RScript

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WritinginanRScriptFile

# ========# 12 Jul 2017# This is my first Rscript# ========6+36-36+3; 6-3

Step2:Toruncommandsonascriptfile:

Usecursortohighlightallthecommandsà RightClickà ChooseRunlineorselection

NOTE:Usesemicolonstoseparatedifferentcommandlines6+3;6-3

Step1:TypetheseinyourRscript file.Note:Thereisno“>“promptinascriptfile

Step3:Saveyourscriptfileinyourpreferreddrive/folder.èsimilartosavinganotepad/textfile

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RObjectAssignment

# use symbol ‘=‘ or ‘ x = 2> x > x x

# CALL UP the r-object to display results

(if required)

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RObjectAssignment

# Use ‘;’ to combine line commands

• Ingeneral,RobjectsarestoredinanRworkspace,alsoknownastheglobalenvironment.

> x = 2; x > len = 2; len> x=2; len=2;x+2

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HandyTip2

• Usebracketsaroundassignment– toautomaticallycallupstoredobject

# Use ‘()’ to auto call up assignment

> (x=2)> (len=2)

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ImportantRulesonobjectassignment• Variablenamesarecasesensitive• Noblanksinname

(canuse_or.tojoinwords,butnot-)• Startwithaletter(capitalorlower-case)

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HandyTip3

• IfacommandisnotcompleteattheendofalinethenRwillissuethefollowingprompt(bydefault):

+onthesecondandsubsequentlinesuntilthecommandsyntaxiscorrect.Tobreakoutofthis,typeCTRL+z(presstheControlKeyand‘z’atthesametime).

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FUNTip!

• Youcanchangetheappearanceofyourpromptsymbol‘>’tosomeotherform:

> options(prompt="R>")

Toreturntothedefaultprompt:> options(prompt=">")

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SavingStuff&Exiting

• Bringsuptothisscreen:• makeitapracticetosave

yourworkonascriptfile

• Unlessyouneedtorecallcertainobjectsregularly,wedonotneedtosavetheworkspace.

• Workspaceisyourcurrentworkingenvironment.Thisincludesallthefunctions, objectsetc thatyouhavecreatedinthatsession.

• Toexit:• hitX(top rightcorner)

oratRprompt

>quit ( )

SAVING EXITING

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Outline




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39

WhichtypeofRUserareyou?

NON-CASUALUSERCASUALUSER



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MainInterface Options-RUsers

Rbase

RCommander

RStudio



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MainInterface Options-RUsers

NOVICETOEXPERIENCEDUSER rbase

BACK-END

rstudio

FRONT-END

NON-CASUALUSER:

• command-lines&point+click• IntegratedDevelopment

Environment(IDE)forR• RStudiomakeslifemuch

easierforRcodingbut itisnotamust-havetouseRpower.

• command-lines• Basicplatformtowrite

programandruncodeinR

Rcommander

FRONT-END

CASUALUSER

• Pointandclick• Integrated

DevelopmentEnvironment(IDE)for

• R-GUIbasedversionofbaseR



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RInterface:RbasevsRStudio

Rbase RStudio



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RInterface:RCommander

Rcommander

• Pointandclick• Dropdownfunctions• IntegratedDevelopment

Environment(IDE)forR-• GUIbasedversionofbaseR



References

• Slidesadapted fromT.P.Hogan,ABriefIntroductoryGuide,SAGEPublications,2010

T. Martin,TheUndergraduateGuidetoRW.J.Braunetal,AFirstCourseInStatisticalProgrammingwithR(2008)

OtherwaystolearnR:http://swirlstats.com/

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NEXT

●PARTB:CoreofRRFunctionsRPackagesRHelp

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part a: r intro - universiti teknologi malaysia · 2018. 10. 13. · workshop: getting started with...

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