MATLAB教程(第5版R2021a) 习题参考答案汇 郑阿奇 第1-7章 MATLAB R2021a环境 - Simulink仿真环境

网络文档A 习题参考答案第1章 MATLABR2021a环境1．略a=2.5000b=a=2.5000b=30c=2.5000 30.00003．标点符号 ; 可以使命令行不显示运算结果， % 用来表示该行为释。4．“format”令数据出式， formatlong或formatlongg 将pi显为3.14159265358979， formatshorte 将pi显为3.1416e+000。5．略6．显示当前文件夹： >>cd CMyDi >>cdC:\MyDir >>a=5.3;>>b=[12;34];>>who;>>whos;>>exista;>>a=5.3;>>b=[12;34];>>who;>>whos;>>exista;>>existb;>>saveC:\MyDir\exe0101;>>clear;9.>>cdC:\ProgramFiles\Polyspace\R2021a>>cdC:\ProgramFiles\Polyspace\R2021a>>dir;>>matlabroot;网络档A 参>>what;>>what;>>typelicense_agreement.txt;>>whichlicense_agreement.txt;10．略第2章 MATLAB数值计算1. （1）A（2）C（3）B（4）C（5）D（6）C >>a=2+3i;b=3-4i>>a+b>>a=2+3i;b=3-4i>>a+b>>ab>>c=a*b>>a/b>>real(c)>>imag(c)>>abs(c)>>angle(c)3.>>x1=0:0.4*pi:4*pi>>x1=0:0.4*pi:4*pi>>x2=linspace(0,4*pi,10)>>a=[123;456;789]>>a(1,3)>>a=[123;456;789]>>a(1,3)>>a（6）>>a(2:end,:)>>l1=logical([101])>>l2=logical([101])>>a(l1,l2)5.>>a=magic>>a=magic（3）>>b=eye（3）>>c=[a,b]>>d=[a;b]>>e=d(6,:)>>a=[123;456;789]>>flipud(a)>>a=[123;456;789]>>flipud(a)>>fliplr(a)>>rot90(a)>>diag(a)>>triu(a)>>tril(a)7.>>a='hello';>>a='hello';>>b1=a+4（5版，R2021a）>>b2=char(b1)>>b2=char(b1)>>b3=rot90(b2)>>b=rot90(b3)>>a=[12;34];>>a'>>a=[12;34];>>a'>>inv(a)>>rank(a)>>det(a)>>a^3>>[v,d]=eig(a)9.>>a=[2-312;1301;1-118;71-22]>>a=[2-312;1301;1-118;71-22]>>b=[8;6;7;5];>>x=a\b>>a=[123;456;789];>>b=[111;222;333];>>a=[123;456;789];>>b=[111;222;333];>>a/b>>a\b>>a./b>>a.\b11.>>a=[1.6-2.45.4-0.8]>>a=[1.6-2.45.4-0.8]>>ceil(a)>>fix(a)>>floor(a)>>round(a)>>t=0:0.1*pi:2*pi;>>z=0.707;>>t=0:0.1*pi:2*pi;>>z=0.707;>>f=10*sqrt(1-z^2)*exp(-2*t).*sin(4*t)>>y=(f>=0)>>f1=f.*y13.>>a=uint8(rand(3)*100)>>a=uint8(rand(3)*100)>>b=max(a)>>c=max(b)>>[m,n]=find(a==c)>>a1=[12;34];>>a2=[12;21]>>a1=[12;34];>>a2=[12;21]>>a3=[11;22]网络档A 参>>a=cat(3,a1,a2,a3)>>a=cat(3,a1,a2,a3)>>b=reshape(a,[322])15.>>d=date>>d=date>>t0=clock;>>a1=[12;34];>>a2=[12;21]>>a3=[11;22]>>a=cat(3,a1,a2,a3)>>b=reshape(a,[322])>>t1=clock;>>t=etime(t1,t0)>>a=eye(4))>>a(4,:)=[-1-2-31];>>a=eye(4))>>a(4,:)=[-1-2-31];>>b=randn(4)>>a=sparse(a)>>c=a+b>>d=a.*b>>whos17.>>a=[54321];>>a=[54321];>>b=[301];>>c=conv(a,b)>>roots(c)>>polyval(c,2)>>[r,p,k]=residue(b,a)>>x=0:0.5:20;>>p=[54321];>>x=0:0.5:20;>>p=[54321];>>y=polyval(p,x);>>p1=polyfit(x,y,2)>>p2=polyfit(x,y,3)>>p3=polyfit(x,y,4)19.>>T=readtable('xt19.xlsx','Range','C1:C6');>>T=readtable('xt19.xlsx','Range','C1:C6');>>s=table2array(T);>>[smax,n]=max(s)>>Brange1=['B',num2str(n)]>>Brange2=['B',num2str(n+1)]>>NameMax=readtable('xt19.xlsx','Range',[Brange1,':',Brange2])20. >>t=0:0.1:10; （5版，R2021a）>>y=exp(2*t).*sin(10*t+30/180*pi);>>y=exp(2*t).*sin(10*t+30/180*pi);>>max(y)>>min(y)>>mean(y)>>diff(y);>>trapz(t,y);>>t=0:0.1:10;>>y=exp(2*t).*sin(10*t+30/180*pi);>>t=0:0.1:10;>>y=exp(2*t).*sin(10*t+30/180*pi);>>N=128;>>fy=fft(y,N);第3章 MATLAB符号计算1. >>f=sym('a*x^3+b*x^2+c*x+d') >>symsabcxyzt>>A=sym([a*cos(x)+b*sin(y)'10+20';a*x^2+b*y^2+c*z^2sqrt(t^2+1)])>>symsabcxyzt>>A=sym([a*cos(x)+b*sin(y)'10+20';a*x^2+b*y^2+c*z^2sqrt(t^2+1)])3.>>A=sym('[ab;cd]')>>A=sym('[ab;cd]')>>B=sym('[cd;ab]')>>A+B>>A-B>>A*B>>A/B>>A.*B>>A./B>>A.^B>>sym(pi/3)>>sym(pi/3,'d')>>sym(pi/3)>>sym(pi/3,'d')>>sym('pi/3')>>sym(exp(2))>>sym(exp(2),'d')>>sym('exp(2)')>>sym(sin(0.3*pi))>>sym(sin(0.3*pi),'d')>>sym('sin(0.3*pi)')5.w x theta a xw x theta a x>>f=sym('sin(x)^2+cos(x)^2')>>pretty(f)>>f=sym('sin(x)^2+cos(x)^2')>>pretty(f)>>simple(f)7.>>f=sym('1-sin(x)^2')>>f=sym('1-sin(x)^2')>>g=sym('2*x+1')>>subs(f,1)>>compose(f,g)>>finverse(g)>>f=sym('x^3+3*x^2-6*x+5')>>sym2poly(f)>>f=sym('x^3+3*x^2-6*x+5')>>sym2poly(f)网络档A 参>>subs(f,'a')>>subs(f,'a')>>subs(f,5)9.>>f=sym('a*x^3+b*y^2+c*z+d')>>f=sym('a*x^3+b*y^2+c*z+d')>>diff(f)>>diff(f,'y')>>diff(f,'c')>>diff(f,'d')>>limit(f,'y',1)>>diff(f,2)>>diff(f,3)>>findsym(f)>>f=sym('x^(-y)')>>int(f)>>f=sym('x^(-y)')>>int(f)>>int(f,'y')>>int(f,'y',0,1)11.>>symsx>>symsx>>taylor(sin(x),10)>>symsst>>f=sym((2*x^2+3*x+3)/((s+1)*(s+3)^3))>>symsst>>f=sym((2*x^2+3*x+3)/((s+1)*(s+3)^3))>>[n,d]=numden(f)>>ilaplace(f,s,t)13.>>symstkTz>>symstkTz>>f=sym(k*exp(-k*T))>>ztrans(f,t,z)>>symsxy>>dsolve('Dy+y*tan(x)=cos(x)','x')>>symsxy>>dsolve('Dy+y*tan(x)=cos(x)','x')15.>>x=sym('x')x=>>x=sym('x')x=x>>y=str2sym('sin(x)/x')y=sin(x)/x>>ezplot(x,y,[1,10])绘制的图形如下图所示。（5版，R2021a）16．17． 略 第4章 MATLAB计算的可视化和GUI设计>>t=0:0.01:2;>>y=2*sin(3*pi*t+pi/4);>>t=0:0.01:2;>>y=2*sin(3*pi*t+pi/4);>>plot(t,y)2.>>t=0:0.1:4*pi;>>t=0:0.1:4*pi;>>y1=sin(t);>>plot(t,y1,'k-.')>>holdon>>t=pi:0.1:3*pi;>>y2=2*cos(2*t);>>plot(t,y2,'r-o')>>set(gca,'xtick',[0pi2*pi3*pi4*pi])>>set(gca,'xticklabel',{'0''π''2π''3π''4π'})>>legend('sin(t)','2cos(2t)')>>grid>>t=0:0.01:2;>>y=sqrt(2)*exp(-t).*sin(2*pi*t+pi/4);>>t=0:0.01:2;>>y=sqrt(2)*exp(-t).*sin(2*pi*t+pi/4);>>plot(t,y,'r');>>axis([02-22]);>>holdon;>>y1=sqrt(2)*exp(-t);>>plot(t,y1,'b-');>>holdon;>>y2=-sqrt(2)*exp(-t);>>plot(t,y2,'b-');4.>>t=0:0.01:2;>>t=0:0.01:2;>>y1=sin(2*pi*t);>>y2=cos(2*pi*t);>>y3=exp(-4*t);>>plot(t,y1,'b');>>holdon;>>plot(t,y2,'g:');>>holdon;>>plot(t,y3,'r');>>set(gca,'xtick',[00.511.52]);>>xlabel('t(0-2)');>>ylabel('幅值');（5版，R2021a）网络网络档A 习题参>>title('>>title('正弦、余弦和指数曲线');>>text(1.4,sin(2*pi*1.4),'\leftarrow正弦曲线');>>text(0.47,sin(2*pi*1.4),'余弦曲线\rightarrow');>>text(1.1,exp(-4*1.1)-0.05,'\uparrow指数曲线');>>x=-2:0.1:2;>>y=x;>>x=-2:0.1:2;>>y=x;>>[x1,y1]=meshgrid(x,y);>>z1=x1.*exp(-(x1.^2+y1.^2));>>plot3(x1,y1,z1)>>surf(x1,y1,z1)>>x1(10:20,10:20)=nan>>surf(x1,y1,z1)6.>>x=-5:0.5:5;>>x=-5:0.5:5;>>y=x;>>[x1,y1]=meshgrid(x,y);>>z1=x1.^2+y1.^2;>>figure(1)>>surf(x1,y1,z1)>>shadinginterp>>figure(2)>>mesh(x1,y1,z1)>>colormapspring>>colorbar>>w=logspace(-2,3,200);>>Aw=1./(sqrt(w.^2+1).*sqrt((0.5*w).^2+1));>>w=logspace(-2,3,200);>>Aw=1./(sqrt(w.^2+1).*sqrt((0.5*w).^2+1));>>Lw=20*log10(Aw);>>semilogx(w,Lw)8.>>w=logspace(-2,3,200);>>w=logspace(-2,3,200);>>Aw=1./(sqrt(w.^2+1).*sqrt((0.5*w).^2+1));>>Fw=-atan(w)-atan(0.5*w);>>polar(Fw,Aw);>>title('幅相频率特性曲线')>>u=5;r=2;c=0.5i;>>z=r+c;>>u=5;r=2;c=0.5i;>>z=r+c;>>i=u/z;>>uc=i*c;>>ur=i*r;>>figure(1)>>compass(u);>>compass(u);>>holdon;>>compass(i);>>compass(uc);>>compass(ur);>>figure(2)>>feather([u,i,uc,ur])>>x1=[609011012010095];>>bar(x1)>>x1=[609011012010095];>>bar(x1)>>e=[000001];>>pie(x1,e,{'一月份','二月份','三月份','四月份','五月份','六月份'})>>x2=[50809010010090];>>x=[x1;x2];>>bar3(x)11.菜单在可视化图形界面环境中设计，过程略。>>prompt={'请输入幅值>>prompt={'请输入幅值','请输入相角'};>>defans={'1','0'};>>p=inputdlg(prompt,'输入正弦信号参数',1,defans)>>helpdlg('正弦信号幅值应大于0','帮助信息')>>button=questdlg('是否确认？','Areyousure?')>>msgbox(['正弦信号幅值为',p{1,1},'正弦信号相角为',p{2,1}])>>x=0:0.1:2*pi;>>plot(x,eval(p{1,1})*sin(x+eval(p{2,1})))第5章 MATLAB程序设计1.略%EXE0502向量运算t=[0:0.05*pi:2*pi];y1=5*exp(-2*t).*sin(4*t);y2=5*exp(-2*t).*cos(4*t);A=[t;y1;y2]2%EXE0502向量运算t=[0:0.05*pi:2*pi];y1=5*exp(-2*t).*sin(4*t);y2=5*exp(-2*t).*cos(4*t);A=[t;y1;y2]3.sum=0;forn=1:10sum=n^n+sumsum=0;forn=1:10sum=n^n+sumendsum用while循环：n=1;n=1;sum=0;whilen<=10sum=n^n+sumn=n+1;endn=1;n1=0;n2=0;whilen<=10a=input('请输入数据：');ifa>0n=1;n1=0;n2=0;whilen<=10a=input('请输入数据：');ifa>0disp('positiveone')n1=n1+1;elseifa<0disp('negativeone')n2=n2+1;elsebreak;endn=n+1;enddisp('positive')n1disp('negative')网络网络档A 习题参（5版，R2021a） n2 5．M函数文件代码如下：functionexe0505()EXE0505 统计分数x=[6075859652368656948477];c=count1(x)d=change1(x)functionz1=count1(xx)%统计分数段个数n=size(xx);z1=zeros(5,1);forn1=1:n(2)x1=fix(xx/10);switchx1(n1)case9 %90分以上为优z1(1)=z1(1)+1;case8 %80分以上为良z1(2)=z1(2)+1;case7 %70分以上为中z1(3)=z1(3)+1;case6 %60分以上为及格z1(4)=z1(4)+1;otherwise %其余为不及格z1(5)=z1(5)+1;endendfunctionz1=change1(xx)%转换成绩n=size(xx);forn1=1:n(2)x1=fix(xx/10);switchx1(n1)case9str1='优';case8str1='良';case7str1='中';case6str1='及格';otherwisestr1='不及格';endendifn1==1z1=str1;elsez1=char(z1,str1);endendfunctionexe0506()EXE0506 分段画曲面x1=-2:0.1:2;functionexe0506()EXE0506 分段画曲面x1=-2:0.1:2;x2=-2:0.1:2;[xx1,xx2]=meshgrid(x1,x2);[n1,m1]=size(xx1);z=zeros(n1,m1);forn=1:n1form=1:m1ifxx1(n,m)+xx2(n,m)>1z(n,m)=calp1(xx1(n,m),xx2(n,m));elseif(xx1(n,m)+xx2(n,m)>-1)&(xx1(n,m)+xx2(n,m)<=1)z(n,m)=calp2(xx1(n,m),xx2(n,m));elsez(n,m)=calp3(xx1(n,m),xx2(n,m));endendendsurf(xx1,xx2,z);functionz=calp1(x,y)z=0.5457*exp(-0.75*y^2-3.75*x^2-1.5*x);functionz=calp2(x,y)z=0.7575*exp(-y^2-6*x^2);functionz=calp3(x,y)z=0.5457*exp(-0.75*y^2-3.75*x^2+1.5*x);7．M函数文件EXE0507.m代码如下：根据输入参数画图根据输入参数画图%EXE0507ifnargin==0disp('无输入参数')elseifnargin==1r=varargin{1};x=[00rr];functionExe0507(varargin)y=[0rr0];y=[0rr0];plot(x,y)elser1=varargin{1};r2=varargin{2};x=[00r1r1];y=[0r2r20];plot(x,y)end8. >>pcodeEXE0507.m >>f=inline('log10(x)+sin(2*y)','x','y')>>f(2,0.3)>>f=inline('log10(x)+sin(2*y)','x','y')>>f(2,0.3)10.functionexe0506()x=[6075859652368656948477];functionexe0506()x=[6075859652368656948477];h_count1=@count1;h_change1=@change1;c=feval(h_count1,x)d=feval(h_change1,x)11.functiony=Exe0511(x)functiony=Exe0511(x)y=-exp(-x)*abs(sin(sin(x)));>>h_Exe0511=@Exe0511;>>[x,y]=fminbnd(h_Exe0511,-0.5,0.5)>>h_Exe0511=@Exe0511;>>[x,y]=fminbnd(h_Exe0511,-0.5,0.5)12. >>area=quad(@sin,0.1,1) 13.%--------------------------------------------------------------------functionvarargout=pushbutton_bar_Callback(h,eventdata,handles,varargin)x=0:0.1:2*pi;%--------------------------------------------------------------------functionvarargout=pushbutton_bar_Callback(h,eventdata,handles,varargin)x=0:0.1:2*pi;y=sin(x);val=get(h,'value')ifval==1bar(y)end%--------------------------------------------------------------------functionvarargout=pushbutton_fill_Callback(h,eventdata,handles,varargin)x=0:0.1:2*pi;y=sin(x);val=get(h,'value')ifval==1y=sin(x);val=get(h,'value')ifval==1fill(x,y,'r')end%--------------------------------------------------------------------functionvarargout=pushbutton_stairs_Callback(h,eventdata,handles,varargin)x=0:0.1:2*pi;y=sin(x);val=get(h,'value')ifval==1stairs(y)end%--------------------------------------------------------------------functionvarargout=pushbutton_hist_Callback(h,eventdata,handles,varargin)x=0:0.1:2*pi;y=sin(x);val=get(h,'value')ifval==1hist(y)end>>x=0:0.1:2*pi;>>y=sin(x);>>x=0:0.1:2*pi;>>y=sin(x);>>plot(x,y)>>h=line('color','blue','marker','.','markersize',30,'erasemode','xor');>>fori=1:length(x)set(h,'xdata',x(i),'ydata',y(i));drawnowend第6章 线性控制系统分析与设计%状态空间模型%状态空间模型%零极点模型%部分分式法模型>>num=[48];>>den=[1650];>>sys=tf(num,den)>>sys1=ss(sys)>>sys2=zpk(sys)>>[r,p,k]=residue(num,den)2.>>num=1;>>num=1;>>den=[0.1110];>>t=0:0.1:20;>>figure(1)>>impulse(num,den,t)>>figure(2)>>step(num,den,t)3.>>num=[611610];>>den=[12311];>>sys=tf(num,den);>>sys1=zpk(sys)>>num=[611610];>>den=[12311];>>sys=tf(num,den);>>sys1=zpk(sys)>>[r,p,k]=residue(num,den)（2） >>[a,b,c,d]=ssdata(sys) （3） >>Dsys=c2d(sys,1) >>[dnum,dden]=tfdata(Dsys);>>dstep(dnum{1},dden{1},10)>>dimpulse(dnum{1},dden{1},10)（>>[dnum,dden]=tfdata(Dsys);>>dstep(dnum{1},dden{1},10)>>dimpulse(dnum{1},dden{1},10)4.>>G1=tf(16,[140]);>>G1=tf(16,[140]);>>G2=tf([0.80],1);>>G12=feedback(G1,G2);>>G=feedback(G12,1)>>G1=tf(16,[140]);>>G=feedback(G1,1)>>G1=tf(16,[140]);>>G=feedback(G1,1)>>[wn,zeta]=damp(G)网络档A 参>>k=dcgain(G)>>k=dcgain(G)>>t=0:0.1:10;>>lsim(G,1+2*t,t)6.>>num=10;>>num=10;>>den=[0.0510];>>G=tf(num,den)>>FG=feedback(G,1)>>[w,z]=damp(FG);>>wn=w(1)>>zeta=z(1)>>detap=exp(-pi*zeta/sqrt(1-zeta^2))*100>>tp=pi/(wn*sqrt(1-zeta^2))>>ts1=3/(zeta*wn)>>a=[-5200;0-400;-32-4-1;-320-4];>>b=[1;2;0;1];>>a=[-5200;0-400;-32-4-1;-320-4];>>b=[1;2;0;1];>>c=[1213];>>d=0;>>G=ss(a,b,c,d);>>w=0:0.01:2*pi;>>ngrid>>nichols(G,w)8.>>num=10;>>num=10;>>den=[0.110];>>G=tf(num,den)>>w=logspace(-1,2);>>subplot(2,2,1)>>[m,p]=bode(num,den,w);>>semilogx(w,20*log10(m))>>gridon>>ylabel('Aw')>>subplot(2,2,3)>>semilogx(w,p)>>grid>>ylabel('Fw')>>subplot(2,2,2)>>nichols(num,den)>>ngrid>>num=10;>>den=[conv([0.051],[0.11]),0]>>num=10;>>den=[conv([0.051],[0.11]),0]（5版，R2021a）>>G=tf(num,den);>>G=tf(num,den);>>w=logspace(-1,2);>>margin(num,den)>>allmargin(G)>>G1=tf(10,[0.1,1]);>>G2=tf(10,[0.05,1,0]);>>G1=tf(10,[0.1,1]);>>G2=tf(10,[0.05,1,0]);>>G3=tf(2000,conv([1,10],[120]));>>nyquist(G1,'r',G2,'b:',G3,'g-.')11.>>num=1;>>num=1;>>den=[15860];>>G=tf(num,den);>>p=pole(G)>>z=tzero(G)>>rlocus(G)>>r=rlocus(G,5)>>num1=1000;>>den1=[conv([0.11],[0.0011])0];>>num1=1000;>>den1=[conv([0.11],[0.0011])0];>>