SAS Data Step 2 Programming

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1、DATAStepProgramming1ContentVariableAttributesReadingSASDataSetsCreating,DroppingandKeepingVariablesConditionalProcessingAdvance:HowtoWriteLinestoanExternalFile(Self-study)ExerciseDefaultVariableAttributesWhenavariableiscreatedinaDATAstep,thename,type,andle

2、ngthofthevariableareautomaticallyassignedremainingattributessuchaslabelandformatarenotautomaticallyassignedexceptthattheyaredefinedwhencreatingvariables.Example0QuestionInwhichstage(compileorexecution),name,type,andlengthofthevariableareautomaticallyassign

3、ed?WhatisthelengthofvariableAafterrunningfollowingcode?dataa;if0=1thenA='abc';elseif1=1thenA='uvwxyz';run;Ifwesetormergemultipledatasetsandavariableexistinginallofthesedatasets,whatvariableattributeswillbe?Example1SpecifyingVariableAttributesUseLABELandFOR

4、MATstatementsinthePROCsteptotemporarilyassigntheattributes(forthedurationofthesteponly)UseLABEL,FORMAT,LENGTH,INFORMAT,FORMATorATTRIBstatementsintheDATAsteptopermanentlyassigntheattributes(storedinthedatasetdescriptorportion).5AssignVariableAttributesLABEL

5、statementAssociatesformatswithvariablessyntaxFORMATstatementAssignsdescriptivelabelstovariablessyntaxLABELvariable-1='label-1'...;FORMATvariable(s);6Exampledatademog;infile"C:ABCraw_data4.txt";inputsubjid$dosedate:MMDDYY10.d

6、osetime:time5.drugname$;formatdosedatedate9.dosetimetime5.;labeldosedate="Thedatewhenreceivingtreatment"dosetime="Thetimewhenreceivingtreatment";run;7AssignInformatsInformatStatementSyntaxinformatspecifiestheinformatforreadingthevaluesofthevariablesthatare

7、listedintheINFORMATstatement.INFORMATvariable(s);8Exampledatatest;informattime1time2time5.sex$char4.;inputsex$time1time2;formattime2time5.;putsex$time1time2;datalines;Female11:1112:12;run;ThePUTstatementproducesthisresu

8、lt:----+----1----+----2----+Fema4026012:129ATTRIBstatementAssociatesaformat,informat,label,and/orlengthwithoneormorevariablesSyntaxATTRIBvariable-list(s)attribute-list(s);10Exampledatademog;infile"C:ABCraw_