42An Introduction to the SAS System

AnIntroductiontotheSASSystemPhilSpectorStatisticalComputingFacilityDepartmentofStatisticsUniversityofCalifornia,Berkeley1WhatisSAS?Developedintheearly1970satNorthCarolinaStateUniversityOriginallyintendedformanagementandanalysisofagriculturaleldexperimentsNowthemostwidelyusedstatisticalsoftwareUsedtostandfor\StatisticalAnalysisSystem,nowitisnotanacronymforanythingPronounced\sass,notspelledoutasthreeletters.2OverviewofSASProductsBaseSAS-datamanagementandbasicproceduresSAS/STAT-statisticalanalysisSAS/GRAPH-presentationqualitygraphicsSAS/OR-OperationsresearchSAS/ETS-EconometricsandTimeSeriesAnalysisSAS/IML-interactivematrixlanguageSAS/AF-applicationsfacility(menusandinterfaces)SAS/QC-qualitycontrolThereareotherspecializedproductsforspreadsheets,accesstodatabases,connectivitybetweendierentmachinesrunningSAS,etc.3Resources:IntroductoryBooksMasteringtheSASSystem,2ndEdition,byJayA.Jae,VanNostrandReinholdQuickStarttoDataAnalysiswithSAS,byFrankC.DiIorioandKennethA.Hardy,DuxburyPress.HowSASworks:acomprehensiveintroductiontotheSASSystem,byP.A.Herzberg,Springer-VerlagAppliedstatisticsandtheSASprogramminglanguage,byR.P.Cody,North-Holland,NewYorkSASInstituteproducesseveralintroductoryguides;mostareataveryelementarylevel.Amongthemare:IntroducingtheSASSystem,Version6,FirstEditionSASLanguageandProcedures:Introduction,Version6,FirstEditionSASIntroductoryGuideforPersonalComputers,Release6.03SASApplicationsProgramming:AGentleIntroductionIntroductiontoMarketResearchUsingtheSASSystemSAS/GRAPHSoftware:Introduction,Version6,FirstEdition4Resources:OtherSASInstitutePublicationsBasicManuals(shouldbeavailableformostserioususers):SASLanguage:Reference,Version6,1stEditionSASLanguageandProcedures:Usage,Version6,1stEditionSASLanguageandProcedures:Usage2,Version6,1stEditionProductManuals(shouldbeavailableforreference)SAS/STATUser'sGuide,Version6,4thEdition,Volumes1&2SAS/ETSUser'sGuide,Version6,2ndEditionSAS/FSPSoftware:UsageandReference,Version6,1stEditionSAS/GRAPHSoftware:Usage,Version6,1stEditionSAS/GRAPHSoftware:Reference,Version6,1stEdition,Volumes1&2SAS/AFSoftware:UsageandReference,Version6,1stEditionSAS/ORUser'sGuide,Version6,FirstEditionSyntax-onlyGuides(maybeusefulforexperiencedusers)SASLanguageandProcedures:Syntax,Version6,1stEditionSASScreenControlLanguage:Syntax,Version6,1stEditionSAS/ETSSoftware:Syntax,Version6,1stEditionSAS/GRAPHSoftware:Syntax,Version6,1stEditionSAS/STATSoftware:Syntax,Version6,1stEdition5Resources:OtherSASInstitutePublicationsSomeOtherPotentiallyUsefulPublicationsSASApplicationsGuide,1987EditionSASCompanionsfor:MVS,Unix,Windows,OS/2,VSE,AOS/VSandCMSSASGuidetotheREPORTProcedure:UsageandReference,Version6SASGuidetoTABULATEProcessing,2ndEditionSASGuidetoMacroProcessing,Version6,1stEditionSAS/ETSSoftware:ApplicationsGuides1&2,Version6,FirstEditionTherearemany,manymoreSASpublications,includingspecializedguidesforvarioussubjectmatterareas,coursenotesandtechnicalreports.ContactSASInstitute,orvisitthewebsite:Whenusingthedisplaymanager,youcangethelponmosttopicsaboutSASbytypinghelpinthewindowinputarea.SamplePrograms:EachdistributionofSAScontainsseveraldirectorieswithsampleprograms.SASInstituteHomePage:://:(equivalenttoSAS-L):comp.soft-sys.sasSASfortheMasses::(s)andtheprocedurestep(s).Thedatastepreadsdatafromexternalsources,manipulatesandcombinesitwithotherdatasetandprintsreports.Thedatastepisusedtoprepareyourdataforusebyoneoftheprocedures(oftencalled\procs).SASisverylenientabouttheformatofitsinput-statementscanbebrokenupacrosslines,multiplestatementscanappearonasingleline,andblankspacesandlinescanbeaddedtomaketheprogrammorereadable.Theprocedurestepsperformanalysisonthedata,andproduce(oftenhugeamountsof)output.ThemosteectivestrategyforlearningSASistoconcentrateonthedetailsofthedatastep,andlearnthedetailsofeachprocedureasyouhaveaneedforthem.8AccessingSASTherearefourwaystoaccessSASonaUNIXsystem:1.Typesas.ThisopenstheSAS\displaymanager,whichconsistsofthreewindows(program,log,andoutput).Someproceduresmustberunfromthedisplaymanager.2.Typesas-nodms.YouwillbepromptedforeachSASstatement,andoutputwillscrollbyonthescreen.3.Typesas-stdio.SASwillactlikeastandardUNIXprogram,expectinginputfromstandardinput,sendingthelogtostandarderror,andtheoutputtostandardoutput;4.Typesasfilename.sas.ThisisthebatchmodeofSAS-yourprogramisreadfromfilename.sas,theloggoestofilename.logandtheoutputgoestofilename.lst.9SomePreliminaryConceptsandRulesSASvariablenamesmustbe8charactersorless,constructedofletters,digitsandtheunderscorecharacter.It'sagoodideanottostartvariablenameswithanunders