資源描述：
《the r book data input》由會(huì)員上傳分享，免費(fèi)在線閱讀，更多相關(guān)內(nèi)容在工程資料-天天文庫(kù)。
1、3DataInputYoucangetnumbersintoRthroughthekeyboard,fromtheClipboardorfromanexternal?le.Forasinglevariableofupto10numbersorso,itisprobablyquickesttotypethenumbersatthecommandline,usingtheconcatenatefunctionclikethis:y<-c(6,7,3,4,8,5,6,2)Forintermediatesizedvariables,youmightwanttoenterdatafromth
2、ekeyboardusingthescanfunction.Forlargerdatasets,andcertainlyforsetswithseveralvariables,youshouldmakeadataframeexternally(e.g.inaspreadsheet)andreaditintoRusingread.table(p.139).3.1DatainputfromthekeyboardThescanfunctionisusefulifyouwanttotype(orpaste)afewnumbersintoavectorcalledxfromthekeyboa
3、rd:x<-scan()1:Atthe1:prompttypeyour?rstnumber,thenpresstheEnterkey.Whenthe2:promptappears,typeinyoursecondnumberandpressEnter,andsoon.Whenyouhaveputinallthenumbersyouneed(supposethereareeightofthem)thensimplypresstheEnterkeyatthe9:prompt.1:62:73:34:45:86:57:68:29:Read8itemsTheRBook,SecondEditi
4、on.MichaelJ.Crawley.?2013JohnWiley&Sons,Ltd.Published2013byJohnWiley&Sons,Ltd.138THERBOOKYoucanalsousescantopasteincolumnsofnumbersfromtheClipboard.Inthespreadsheet,highlightthecolumnofnumbersyouwant,thentypeCtrl+C(theacceleratorkeysforCopy).NowgobackintoR.Atthe1:promptjusttypeCtrl+V(theaccele
5、ratorkeysforPaste)andthenumberswillbescannedintothenamedvariable(xinthisexample).Youcanthenpasteinanothersetofnumbers,orpressReturntocompletedataentry.IfyoutrytoreadinagroupofnumbersfromarowofcellsinExcel,thecharacterswillbepastedintoasinglemulti-digitnumber(de?nitelynotwhatislikelytohavebeeni
6、ntended).So,ifyouaregoingtopastenumbersfromExcel,makesurethenumbersareincolumns,notinrows,inthespreadsheet.Ifnecessary,useEdit/PasteSpecial/TransposeinExceltoturnarowintoacolumnbeforecopyingthenumbers.3.2Datainputfrom?lesTheeasiestwaytogetdataintoRistomakeyourdataintotheshapeofadataframebefore
7、tryingtoreaditintoR.AsexplainedindetailinChapter4,youshouldputallofthevaluesofeachvariableintoasinglecolumn,andputthenameofthevariableinrow1(calledthe‘header’row).Youwillsometimesseetherowsandthecolumnsofthedataframereferredtoascasesand
