IntroductiontoMATLABCheng-HsiungChiangDepartmentofComputerScienceHsuanChuangUniversity1OutlineThehistoryofMATLABThetoolboxesofMATLABHowtouseMATLABsoftware?ProgrammingusingMATLABBasiccommandsWriteafunctionofMATLABArraysandmatrixesOperationsofarraysandmatrixesMatlabfunctionsControlproceduresInputandoutputPlottingExamplesofMATLABprograms2TheHistoryofMATLABMATLAB(MatrixLaboratory)isdevelopedbyTheMathWorks,Inc.,1984.MATLAB最早的發(fā)展理念是提供一套非常完善的矩陣運(yùn)算指令，但隨著數(shù)值運(yùn)算需求的演變，matlab已成為系統(tǒng)模擬，數(shù)位訊號(hào)處理，科學(xué)目視的標(biāo)準(zhǔn)語(yǔ)言3MATLABistheleadingcomputationalsoftwareforProductdesignanddevelopmentResearchinindustryandacademiaTechnicaleducationOver400,000MATLABusersworldwideUsedinover100countries4HowpowerfultheMATLABcanbe?“Forthepurposesofanengineerorscientist,MATLABhasthe

mostfeaturesandisthebestdevelopedprograminitsclass.” -IEEESpectrum,SoftwareReview,February1997“IhavebeenamazedathowMATLABcanboostone’sproductivity.Anythingfromsimpleanalysistocomplexmodelingandsimulationcanbedoneinafractionofthetimeitwouldtaketowriteyourowncode.”GregoryE.Chamitoff,Ph.D.

NASA,JohnsonSpaceCenter5TheToolboxesofMATLABCommunicationsToolboxControlSystemToolboxDataAcquisitionToolboxDatabaseToolboxDatafeedToolboxFilterDesignToolboxFinancialDerivativesToolboxFinancialDerivativesToolboxFinancialToolboxFuzzyLogicToolboxGARCHToolboxImageProcessingToolboxInstrumentControlToolboxModelPredictiveControlToolboxMappingToolboxMuAnalysisAndSynthesisToolboxNeuralNetworkToolboxOptimizationToolboxPartialDifferentialEquations(PDE)ToolboxRobustControlToolboxSignalProcessingToolboxSplineToolboxStatisticsToolboxSymbolicMathToolboxSystemIdentificationToolboxWaveletToolbox6HowtouseMATLAB?InstallMATLABExecuteMATLABTheMATLABwindowsDemosofMATLAB7ProgrammingUsingMATLABFiletypesofMATLAB.mfile.figfiles.matfilesBasicCommandsincommandwindowsave<filename>load<filename>help<command>whoclearclcexit/quit8MathematicalOperationsDeclaringavariable A=5; %the“;”isfornotdisplay B=6;MATLABMath&AssignmentOperators Power ^ or .^ a^b or a.^b Multiplication *or .* a*b or a.*b Division / or ./ a/b or a./bor \ or .\ b\a or b.\a NOTE: 56/88\56 Addition + a+b Subtraction - a-b9WriteaFunctionofMATLABHowtoeditafunctionforMATLAB?AnexampleofaMATLABfunctionfunction[total]=sum(n)%Thisprogramistocalculatethesummationsum=0;fori=1:10, sum=sum+I;end; %endofforloopend; %endoffunctionHowtocallafunction?10ArraysandMatrixesArray:ex.1x6arrayA=[123456]; or A=[1,2,3,4,5,6];Matrix:ex.2x3matrixB=[123;456;789];orB=[123456789];A(1)=?A(6)=?B(1,2)=?B(1,:)=?B(:,1)=?Examples:11OperationsofArraysandMatrixesThemathematicaloperationsofarrayandmatrix12MatlabFunctionsTheMATLABfunctions13Flowcontrol-selectionTheif-elseif-elseconstructionif<logicalexpression><commands>elseif<logicalexpression><commands>else<commands>endifheight>170disp(’tall’)elseifheight<150disp(’small’)elsedisp(’average’)end14LogicalexpressionsRelationaloperators(comparearraysofsamesizes)== (equalto)~=(notequal)< (lessthan) <=(lessthanorequalto)

>(greaterthan)>=(greaterthanorequalto)Logicaloperators(combinationsofrelationaloperators)&(and)|(or)~(not)Logicalfunctionsxorisemptyanyallif(x>=0)&(x<=10)disp(‘‘xisinrange[0,10]’’)elsedisp(‘‘xisoutofrange’’)end15Flowcontrol-repetitionRepeatsacodesegmentafixednumberoftimesforindex=<vector><statements>endThe<statements>areexecutedrepeatedly.Ateachiteration,thevariableindexisassignedanewvaluefrom<vector>.fork=1:12kfac=prod(1:k);disp([num2str(k),’’‘‘,num2str(kfac)])end16Example––selectionandrepetitionfunctiony=fact(n)%FACT––Displayfactorialsofintegers1..nifnargin<1error(’’Noinputargumentassigned’’)elseifn<0error(’’Inputmustbenon-negative’’)elseifabs(n-round(n))>epserror(’’Inputmustbeaninteger’’)endfork=1:nkfac=prod(1:k);disp([num2str(k),’’’’,num2str(kfac)])y(k)=kfac;end;17Repetition:AnimationdemoThefunctionmoviereplaysasequenceofcapturedframesConstructamovieofa360°°touraroundtheMatlablogo%logomovie––makemovieof360degreelogotourlogo;no_frames=40;dtheta=360/no_frames;forframe=1:no_frames,camorbit(dtheta,0)M(frame)=getframe(gcf);end%nowdisplaycapturedmoviemovie(gcf,M);18Flowcontrol––conditionalrepetitionwhile-loops<statements>areexecutedrepeatedlyaslongasthe<logicalexpression>evaluatestotruewhile<logicalexpression><statements>endk=1;whileprod(1:k)~=Inf,k=k+1;enddisp([‘LargestfactorialinMatlab:’’,num2str(k-1)]);19InputandOutputX=input(‘‘enteryourname’,’s’’)Y=input(‘‘enteryourage’’,a)Disp(X)fprintf(fid,'%6.2f\n',y)20PlottingPolarplot:t=0:.01:2*pi;polar(t,abs(sin(2*t).*cos(2*t)));Lineplot:x=0:0.05:5;,y=sin(x.^2);,plot(x,y);Stemplot:x=0:0.1:4;,y=sin(x.^2).*exp(-x);