复旦R语言PPT课件.ppt

R Statistics Programme andWhoareYou AnABCintroductiontoR PresentedbyGuohuiDingR D SIBS CAS ForFudanUniversity MainTopicsToday WhatisR HowtoadministrateR HowdoesRwork HowtoapplyRforstatisticalproblem HowtoprogramyourRfunction WhatisR AbriefhistoryofR ThelegendofR Rstartedintheearly1990 sasaprojectbyRossIhakaandRobertGentlemanattheUniversityofAuckland NewZealand intendedtoprovideastatisticalenvironmentintheirteachinglab ThelabhadMacintoshcomputers forwhichnosuitablecommercialenvironmentwasavailable RobertGentleman RossIhaka R sParents 1 TheSlanguageS aninteractiveenvironmentfordataanalysisdevelopedatBellLaboratoriessince1976ExclusivelylicensedbyAT T LucenttoInsightfulCorporation SeattleWA Productname S plus Youcanlearnmorefrom MyfatherisS motherisScheme butwhymynameis R TheSchemelanguageSchemeisastaticallyscopedandproperlytail recursivedialectoftheLispprogramminglanguageinventedbyGuyLewisSteeleJr andGeraldJaySussman Learnmore Scheme sunderlyingsemantics S syntax R R sParents 2 WehavenamedourlanguageR inparttoacknowledgetheinfluenceofSandinparttocelebrateourownefforts R IhakaR Gentleman RNow Sincemid 1997therehasbeenacoregroupwhocanmodifytheRsourcecodeCVSarchive TheRpackagesystemCRAN theComprehensiveRArchiveNetwork ThecharactersofR Ris GNUS Alanguageandenvironmentfordatamanipula tion calculationandgraphicaldisplay ThatisRisaFreeSoftware orOpensourcesoftware Here Freereferstofreedom notprice althoughRisfreeinthatsenseaswell ThecoreofRisaninterpretedcomputerlanguage Amosaicofprocedure basedprogrammingandobject orientedprogrammingGoodinterfacetoprocedureswritteninC C FORTRANandotherlanguagesAflexibledataexchangemechanismaccessingrelationaldatabases ODBC PostgreSQL MySQLandsoon 小偷与强盗的谈判 RandStatistics Mostpackagesdealwithstatisticsanddataanalysis Powerfulstatisticalgraphics Wellcrosstalkingwithotherstatisticalsoftwares MostRuserarestatisticalexperts Youcanlearnmoremodernanalysismethodfromtheybyemail Youcandoitwhenyoucomeacrossathingnobodydoitbefore InstallandadministrateR FocusonWindows MS HowdoIgetR TheinformationalwebsiteCRAN theComprehensiveRArchiveNetwork Theprimarysiteis Mirrorsitesareavailableformanycountries CRANsiteshavebinarydistributionsforWindows95 98 ME NT4 2000andXPonIntel fortheMacintosh System8 6to9 1andMacOSX andforseveralLinuxdistributions Newreleasesoccurfrequentlyaboutevery3months Bepreparedtore installfrequently Alsoyoucangetitfromyourfriends teachers etc Downit Itisabout20 6Minsize UsingPrecompiledBinaryDistributions InstallingR Doubleclick rw1091 exe usingyourmouse ThatisOK YoucaninstallitasallotherstandardMSsoftwares RConsole RGuiinWindows MS Commandbox Graphicsbox Menu Icons SeveralconceptsinAdministratingR Workspacexxx RDataHistoryxxx RhistoryPackageObjectSessionConsole RunyourRcodes Load saveworkspace Load saveHistory Changeyourworkingdirectory Addanewpackage Commands library addapackageinthelibrarydetach package xxx detachapackageAllcandointheGUI exceptdetach Loadalocalpackage Installpackagesfrominternetorlocal Updatethelocalpackagefrominternet PackagesinREnvironment Basicpackages package methods package stats package graphics package utils package base Recommandedpackagesgrid lattice e1071 Contributedpackages morethan366packagesnowadays Youcanseewhatpackagesloadednowbythecommandsearch Don tloseyourway Threeusefulsystemcommandgetwd GetWorkingDirectorysetwd SetWorkingDirectorylist files ListtheFilesinaDirectory Folder ShowtheDemonstrationsofthePackages Functions Commandsdemo DemonstrationsofRFunctionalityexample RunanExamplesSectionfromtheOnlineHelp GettingHelps Severalcommandshelp start help or help search apropos InternetsearchingIlikeitverymuch Itseemsomnipotence QuitR Commandq TerminateanRSession HowdoesRwork BasicRStructureanddatamanipulation BasicRworkingflow Objectorientation package RforBeginners EmmanuelParadis Objectorientation Object acollectionofatomicvariablesand orotherobjectsthatbelongtogetherParlance class the abstract definitionofitobject aconcreteinstancemethod otherwordfor function slot acomponentofanobject TypesofDatainR Thebasicdataobjectisavectorofelementsoftype numericnumbers eitherfloatingpointorintegercharactereachelementisacharacterstringlogicaleachelementisTRUEorFALSElistelementscanbeanytypeofobject includingotherlistsComponentsoftheSlanguage suchasfunctions arealsovectors AnyvectorcanincludethemissingdatamarkerNAasanelement Allvectorshavealengthandamode Thefunctionslengthandmodereturnthisinformationasdoesthestrfunction Astructureconsistsofadataobjectplusadditionalinformation Matrices orarrays ingeneral andtimeseriesareexamplesofstructures Operators Vectors MatricesandArrays Command array data NA dim length data dimnames NULL matrix data NA nrow 1 ncol 1 byrow FALSE dimnames NULL Lists Listvs Vectorlist anorderedcollectionofdataofarbitrarytypes vector anorderedcollectionofdataofthesametype Typically vectorelementsareaccessedbytheirindex aninteger listelementsbytheirname acharacterstring Butbothtypessupportbothaccessmethods Factors Factors classificationvariablesIfthelevelsofafactorarenumeric e g thetreatmentsarelabelled 1 2 and 3 itisimportanttoensurethatthedataarectuallystoredasafactorandnotasnumericdata Alwayscheckthisbyusingsummary Dataframes dataframe issupposedtorepresentthetypicaldatatablethatresearcherscomeupwith likeaspreadsheet Itisarectangulartablewithrowsandcolumns datawithineachcolumnhasthesametype e g number text logical butdifferentcolumnsmayhavedifferenttypes Alistactually Subsetting Individualelementsofavector matrix arrayordataframeareaccessedwith byspecifyingtheirindex ortheirname UsingRonWindows MS BasicstatisticalanalysisbyR DataInput Fromthekeyboardonebyonec scan Fromthefileread table read csv read csv2 read dta read spss Byaspreadsheetdata entry edit fix DataEdit Commandsedit fix Tips edit caninvokeannotepadintheRGui DataDiscription Commandssummary mean sd hist boxplot ProbabilityDistribution ThreeusefulprefixinProbabilityDistributionFunction dxxxforthedensitypxxxfortheCDFqxxxforthequantilefunctionrxxxforthesimulation randomdeviates Theyaredifferent Theseedissetbythesystem Youcansetseedyourselfbyset seed StatisticalInference Commandsqxxx forthequantilefunctiont test wilcox test stats kruskal test stats var test shapiro test qqnorm qqline AnalysisofvarianceandRegressionAnalysis Commandsanova lm ExperimentDesign Commandssample power t test SaveObject Data EveryRobjectcanbestoredintoandrestoredfromathecommands save and load save x file x Rdata load x Rdata Importingandexportingdatawithrectangulartablesintheformoftab delimitedtextfiles write table x file x txt sep t GraphicswithR AFriendlyREnvironment Rcmdr Ifyoudon tlikeacommandlineenvironment packageRcmdrmaybeagoodchoice Rprogramming R ProgramyourRcodeown ControlFlow if cond exprif cond cons exprelsealt exprfor varinseq exprwhile cond exprrepeatexprbreaknext Loops ThemainloopconstructinRisfor Thecommonestuse asinCandotherlanguages istocountfrom1ton for iin1 n dosomething Leavingloops Thebreakandnextcommandsallowtheflowofalooptobealteredbreakjumpsouttheloopnextjumpstothenextiterationoftheloop AvoidingIteration ThecanonicalbadRprogramlookslikethis multiplytwovectorsfor iin1 n d i a i b i computetheinnerproducts 0for iin1 n s s d i Therightwaytodothisiss sum a b apply lapply sapply WriteR