Matlab基础与应用教程答案人民邮电出版社.doc

第1章一、思考题4. （1） B=A(2:5,1:2:5)（2）A(7)=（3） A=A+30（4）size(A)（5） t(find(t=0)=eps（6）t=reshape(x,3,4)（7）abs(matlab)（8）char(93)5. A=97,67,34,10;-78,75,65,5;32,5,-23,-59;0,-12,54,7 (1) B=A(1:3,:) C=A(:,1:2) D=A(2:4,3:4) E=B*C(2)A(find(A=50 & A120 gz=dj*120+1.15*dj*(h-120);elseif h60 gz=dj*h-700;else gz=dj*h;endformat bank;display(gh,gz)3. 循环结构n=input(input n:);s=0;for k=1:n s=s+1/k2;enddisplay(sqrt(s*6)向量运算n=input(input n:);k=1:n;display(sqrt(sum(1./k.2)*6)4.y=0;k=0;while y=1e-5 & k500 x0=x; x=a/(b+x0); k=k+1;enddisplay(k,x);display(-b+sqrt(b2+4*a)/2,(-b-sqrt(b2+4*a)/2);6.y=fun(40)/(fun(30)+fun(20)（1）函数文件fun.mfunction f=fun(n)f=n+log(n2+5);（2）函数文件fun.mfunction f=fun(n)a=1:n;f=sum(a.*(a+1);第3章一、思考题4. t=0:0.01:1.5;y=sqrt(3)/2*exp(-4*t).*sin(4*sqrt(3)*t+pi/3);5. x=-10:0.01:10;y=linspace(-6,6,size(x,2)z=x.3+3*x.*y.2;plot3(x,y,z)6. x=100:100:400;y=100:100:400;z=636,697,624,478;698,712,630,478;680,674,598,412;662,626,552,334;X,Y=meshgrid(x,y);mesh(X,Y,z)二、实验题1. （1）x=-10:0.01:10;plot(x,x-x.3/3/2)（2）plot(x,exp(-x.*x/2)/2/pi)（3）x=-8:0.01:8;plot(x,sqrt(64-x.*x)/2)（4）t=0:pi/100:6*pi;plot(t.*sin(t),t.*cos(t)2. （1）x1=linspace(0,1,100);y1=2*x1-0.5;t=linspace(0,pi,100);x=sin(3*t).*cos(t);y=sin(3*t).*sin(t);plot(x1,y1,r-,x,y,b:);text(0.4,1,y=2x-0.5);text(-0.4,0.5,x=sin(3t)cos(t);text(-0.4,0.3,y=sin(3t)sin(t);（2） subplot(1,2,1);scatter(x1,y1,10) title(y=2x-0.5);subplot(1,2,2);scatter(x,y,10)3. subplot(1,2,1); x=1:1:100; y=sin(1./x);plot(x,y)subplot(1,2,2);fplot(sin(1/x),1,100)4. subplot(2,2,1);bar(t,y);subplot(2,2,2);stairs(t,y);subplot(2,2,3);stem(t,y)subplot(2,2,4);semilogy(t,y);5. theta=linspace(-pi,pi,100);ro=5.*cos(theta)+4;polar(theta,ro);fi=linspace(0,2*pi,100);a=1r=a.*(1+cos(fi);polar(fi,r);6. t=0:pi/20:2*pi;x=exp(-t./20).*cos(t);y=exp(-t./20).*sin(t);z=t;plot3(x,y,z);t=0:0.01:1;x=t;y=t.2;z=t.3;plot3(x,y,z);7. x=-30:0.1:0;y=0:0.1:30;x,y=meshgrid(x,y);z=10.*sin(sqrt(x.2+y.2)./sqrt(1+x.2+y.2);meshc(x,y,z);8. x=linspace(-3,3,100);y=linspace(-3,3,100);x y=meshgrid(x,y);fxy=-5./(1+x.2+y.2);i=find(abs(x)=0.8 & abs(y)0.5)/size(A)2. h=466,715,950,1422,1635;w=7.04,4.28,3.40,2.52,2.13;hh=500,900,1500;ww=interp1(h,w,hh,spline)3. x=linspace(1,10,50);y=log(x);f=polyfit(x,y,5);yy=polyval(f,x);plot(x,y,r-,x,yy,g.)4. N=64; % 采样点数T=5; % 采样时间终点t=linspace(0,T,N); % 给出N个采样时间ti(I=1:N)x=3*exp(-t); % 求各采样点样本值xdt=t(2)-t(1); % 采样周期f=1/dt; % 采样频率(Hz)X=fft(x); % 计算x的快速傅立叶变换XF=X(1:N/2+1); % F(k)=X(k)(k=1:N/2+1)f=f*(0:N/2)/N; % 使频率轴f从零开始plot(f,abs(F),-*) % 绘制振幅-频率图xlabel(Frequency);ylabel(|F(k)|)5. （1）p1=1 2 0 0 7;p2=1 -2;p3=1 0 0 5 1;p12=conv(p1,p2);p=p12+zeros(1,size(p12,2)-size(p3,2),p3;roots(p)（2）A=-1,4,3;2,1,5;0,5,6;Px=polyval(p,A)Pxm=polyvalm(p,A)6.（1） z=fzero(3*x-sin(x)+1,0)（2） 建立函数文件myfun.mfunction F=myfun(X)x=X(1);y=X(2);F(1)=x*x+y*y-9;F(2)=x+y-1;在命令窗口中输入以下命令：x=fsolve(myfun,3,0,optimset(Display,off)第6章一、思考题2.fx=inline(1./(1+x.2);I,n=quad(fx,-100000,100000,1e-3);I,n=quadl(fx,-100000,100000,1e-3);x=-100000:0.01:100000;y=1./(1+x.*x);trapz(x,y);3.(1) fx=inline(-2*y+2*x*x+2*x);t,y=ode23(fx,0,0.5,1)(2) fx=inline(y-exp(x)*cos(x);t,y=ode23(fx,0,3,1)二、实验题1. for x=1:3 fx=x,x2,x3;1,2*x,3*x;0,2,6*x; diff(fx)end2.（1）x=0:0.01:1;y=x.10+10.x+1./log10(x);dy=diff(y)/0.01;（2）x=0:0.01:1;y=log(1+x);dy=diff(y,2)/0.01;plot(x(1:99),dy)3.（1）fx=inline(x.2.*sqrt(2*x.*x+3); quad(fx,1,5)（2）fx=inline(x./sin(x).2); quad(fx,pi/4,pi/3)（3）fx=inline(abs(cos(x+y); dblquad(fx,0,pi,0,pi)（4）syms x y;fx=x*y; int(int(fx,y2,y+2),-1,2)x的积分区间为【0，2】时fx=inline(x.*y); dblquad(fx,0,2,-1,2)4.x=0.3:0.2:1.5;y=0.3895,0.6598,0.9147,1.1611,1.3971,1.6212,1.8325;trapz(x,y)5.（1）yp=inline(-(1.2+sin(10*x)*y); t,y=ode23(yp,0,5,1); （2）令，则可写出原方程的状态方程形式： - 建立函数文件ztfun.mfunction y=ztfun(t,x)b=0;0;cos(t);y=0,1,0;0,0,1;-1/(3+sin(t),-1,5*cos(2*t)/(t+1)2*x+b;解微分方程组t,y=ode23(ztfun,0,5,1;0;2);6.建立函数文件ztfun.mfunction yy=ztfun(t,y)yy=y(2)*y(3);-y(1)*y(3);-0.51*y(1)*y(2);解微分方程组t,y=ode23(ztfun,0,5,0;1;1)第7章一、思考题3.（1）数值积分fx=inline(exp(x).*(1+exp(x).2);quad(fx,0,log(2)符号积分f=sym(exp(x)*(1+exp(x)2);v=int(f,0,log(2);eval(v)（2）略二、实验题1.A=sym(1,2,3;x,y,z;3,2,1)rank(A)inv(A)det(A)2.(1) y=sym(sqrt(x+sqrt(x+sqrt(x);y1=diff(y)y2=diff(y,x,2)(2) syms x y;fxy=sin(x2*y)*exp(-x2-y);diff(diff(fxy,x),y)3.(1) syms xint(1/(1+x4)(2) syms x tint(-2*x*x+1)/(2*x*x-3*x+1)2,x,cos(t),exp(2*t)4.syms n xsymsum(1/(2*n+1)/(2*x+1)(2*n+1),n,0,inf)symsum(1/(2*n+1)/(2*x+1)(2*n+1),n,0,5)5.(1) syms xtaylor(exp(x)+exp(-x)/2,5,0)(2) syms a xtaylor(exp(-5*x)*sin(3*x+pi/3),5,a)6.(1)x=solve(sym(x3+a*x+1=0)(2) x y=solve(sym(sqrt(x2+y2)-100=0,3*x+5*y-8=0)7. 方程转化为： 符号解y1,y11=dsolve(Dy=y1,Dy1+y=1-t2/pi,y(-2)=5,y1(-2)=5,t)数值解编写函数文件ztfun.mfunction yy=ztfun(t,y)yy=y(2);1-t2/pi-y(1);在命令窗口输入以下命令t,y=ode45(ztfun,-2,7,-5;5);t=linspace(-2,7,49)y2=y8. x,y=dsolve(Dx=3*x+4*y,Dy=-4*x+3*y,x(0)=0,y(0)=1)第9章二、实验题1.（1）新建一个Blank GUI。（2）在窗口上添加一个Static Text、一个Edit Text，一个Push Botton，两个Check Box，一组Radio Button。各控件的属性设置如表9.1所示。表9.1界面控件属性控 件属 性 名属 性 值静态文本框String实验一：编辑框String按钮String设置字体大小单选按钮1Stringred单选按钮2Stringyellow单选按钮3Stringblue单选按钮4StringblackValue1.0复选框1String倾斜复选框2String加粗（3）在按钮的Callback函数中添加以下代码：s=eval(get(handles.edit1,String);set(handles.text1,FontSize,s);（4）在复选框1的Callback函数中添加以下代码：if (get(hObject,Value) = get(hObject,Max) set(handles.text1,FontAngle,italic);else set(handles.text1,FontAngle,normal);end在复选框2的Callback函数中添加以下代码：if (get(hObject,Value) = get(hObject,Max) set(handles.text1,FontWeight,bold);else set(handles.text1,FontAngle,normal);end（5）在单选按钮组的SelectionChangeFcn函数中添加以下代码：set(handles.text1,ForegroundColor,get(eventdata.NewValue,string);2.（1）新建一个Blank GUI。（2）用菜单编辑器编辑菜单，各菜单项属性如表9.2.表9.2菜单项属性菜单项Label 属 性 值Tag 属 性 值MenuLineLabelm_lineHelpHelpm_helpLine Menu ItemLine StyleLine Stylem_linestyleLine WidthLine Widthm_linewidthLine ColorLine Colorm linecolorHelp Menu ItemAboutAboutm_about（3）绘图。在窗口的OpeningFcn函数添加以下代码：global h;t=0:0.01:6;h=plot(t.*sin(t),t.*cos(t)（4）在Line Style菜单项的Callback函数中添加以下代码：global h;set(h,LineStyle,-.);在Line Width菜单项的Callback函数中添加以下代码：global h;set(h,LineWidth,2);在Line Color菜单项的Callback函数中添加以下代码：global h;set(h,color,red);在About菜单项的Callback函数中添加以下代码：msgbox(Help Item);3.t=0:pi/20:6*pi;a=2;b=3;r=a+b*t;h_draw=polar(t,r,-*);h_menu=uicontextmenu; % %uimenu(h_menu,Label,red,Call,set(h_draw,Color,red););uimenu(h_menu,Label,yellow,Call,set(h_draw,Color,yellow););uimenu(h_menu,Label,blue,Call,set(h_draw,Color,blue););set(h_draw,UIContextMenu,h_menu); %4.（1）新建一个Blank GUI。（2）在窗口上添加三个Static Text、三个Edit Text，一个Push Botton，一个坐标轴对象Axes。各控件的属性设置如表9.3所示。表9.3界面控件属性控 件属 性 名属 性 值Static Texttext1Stringa：text1Stringb：text1Stringn：Edit Textedit1Stringedit2Stringedit3Stringpushbotton1String绘图Axes1width100height25（3）在按钮pushbutton1的Callback函数中添加以下代码：t=0:pi/20:6*pi;a=eval(get(handles.edit1,String);b=eval(get(handles.edit2,String);n=eval(get(handles.edit3,String);r=a.*cos(b+n.*t);polar(handles.axes1,t,r);第10章二、实验题1.建立模型exercise10_1.mdl（1）双击Gain模块，打开Function Block Parameters进行设置。设置完成后，单击模型编辑窗口的Start Simulation按钮，观察曲线。（2）选择Math Operation模块库的Slide Gain模块替代Gain模块2.略3. Scope的双输入实现方法：双击Scope模块，打开Scope示波器窗口，单击该窗口工具栏的Parameters 按钮（左数第二个），在打开的对话框的General选项卡的Numbers of axes:后的编辑框中输入2，然后单击OK按钮返回，即可看到模型中的Scope模块增加了一个输入口4.（1）先建立如下模型（2）建立子系统。选中除输入输出模块外其他模块，执行Edit菜单的Create Subsystem命令。（3）封装子系统。选中子系统模块，执行Edit菜单的Mask Subsystem命令。在Mask Editor对话框的Parameters选项卡中的Dialog Parameters栏内增加三个变量，单击OK按钮返回。5.（1）建立S函数subsection.mfunction sys,x0,str,ts=subsection(t,x,u,flag)switch flagcase 0 sys,x0,str,ts=mdlInitializeSizes; case 3 sys=mdlOutputs(t,x,u); case 1,2,4,9 sys=;otherwise error(Unhandled Flag, num2str(flag);end function sys,x0,str,ts=mdlInitializeSizes()sizes=simsizes;sizes.NumContStates=0; sizes.NumDiscStates=0; sizes.NumOutputs=1; sizes.NumInputs=1; sizes.DirFeedthrough=1; sizes.NumSampleTimes=1; sys=simsizes(sizes);x0=; str=; ts=-1,0; function sys=mdlOutputs(t,x,u)if u=0 & u=2 & u=5 & u=a & textall(n)=z textall(n)=char(textall(n)-(a-A); end m=textall(n)-A+1; ch(m)=ch(m)+1; endend4. (1)编辑c源程序exercise11_4.c，代码如下：#include #include /* For strcmp() */#include /* For EXIT_FAILURE, EXIT_SUCCESS */#include #include mat.h#define BUFSIZE 256#define k1 39#define k2 71 int main() MATFile *pmat; mxArray *pa1, *pa2, *pa3; double datak1k2; const char *file = mat11_4.mat; char strBUFSIZE; int status; int n1,n2; for(n1=0;n1k1;n1+) for(n2=0;n2k2;n2+) datan1n2=pow(n1+1.0)*(n2+1),1/3.0); printf(Creating file %s.nn, file); pmat = matOpen(file, w); if (pmat = NULL) printf(Error creating file %sn, file); printf(Do you have write permission in this directory?)n); return(EXIT_FAILURE); pa1 = mxCreateDoubleMatrix(k1,k2,mxREAL); if (pa1 = NULL) printf(%s : Out of memory on line %dn, _FILE_, _LINE_); printf(Unable to create mxArray.n); return(EXIT_FAILURE); pa2 = mxCreateDoubleMatrix(k1,k2,mxREAL); if (pa2 = NULL) printf(%s : Out of memory on line %dn, _FILE_, _LINE_); printf(Unable to create mxArray.n); return(EXIT_FAILURE); memcpy(void *)(mxGetPr(pa2), (void *)data, sizeof(data); pa3 = mxCreateString(MATLAB: the language of technical computing); if (pa3 = NULL) printf(%s : Out of memory on line %dn, _FILE_, _LINE_); printf(Unable to create string mxArray.n); return(EXIT_FAILURE); status = matPutVariable(pmat, LocalDouble, pa1); if (status != 0) printf(%s : Error using matPutVariable on line %dn, _FILE_, _LINE_); return(EXIT_FAILURE); status = matPutVariableAsGlobal(pmat, GlobalDouble, pa2); if (status != 0) printf(Error using matPutVariableAsGlobaln); return(EXIT_FAILURE); status = matPutVariable(pmat, LocalString, pa3); if (status != 0) printf(%s : Error using matPutVariable on line %dn, _FILE_, _LINE_); return(EXIT_FAILURE); memcpy(void *)(mxGetPr(pa1), (void *)data, sizeof(data); status = matPutVariable(pmat, LocalDouble, pa1); if (status != 0) printf(%s : Error using matPutVariable on line %dn, _FILE_, _LINE_); return(EXIT_FAILURE); mxDestroyArray(pa1); mxDestroyArray(pa2); mxDestroyArray(pa3); if (matClose(pmat) != 0) printf(Error closing file %sn,file); return(EXIT_FAILURE); pmat = matOpen(file, r); if (pmat = NULL) printf(Error reopening file %sn, file); return(EXIT_FAILURE); pa1 = matGetVariable(pmat, LocalDouble); if (pa1 = NULL) printf(Error reading existing matrix LocalDoublen); return(EXIT_FAILURE); if (mxGetNumberOfDimensions(pa1) != 2) printf(Error saving matrix: result does not have two dimensionsn); return(EXIT_FAILURE); pa2 = matGetVariable(pmat, GlobalDouble); if (pa2 = NULL) printf(Error reading existing matrix GlobalDoublen); return(EXIT_FAILURE); if (!(mxIsFromGlobalWS(pa2) printf(Error saving global matrix: result is not globaln); return(EXIT_FAILURE); pa3 = matGetVariable(pmat, LocalString); if (pa3 = NULL) printf(Error reading existing matrix LocalStringn); return(EXIT_FAILURE); status = mxGetString(pa3, str, sizeof(str); if(status != 0) printf(Not enough space. String is truncated.); return(EXIT_FAILURE); if (strcmp(str, MATLAB: the language of technical computing) printf(Error saving string: result has incorrect contentsn); return(EXIT_FAILURE); /* clean up before exit */ mxDestroyArray(pa1); mxDestroyArray(pa2); mxDestroyArray(pa3); if (matClose(pmat) != 0) printf(Error closing file %sn,file); return(EXIT_FAILURE); printf(Donen); return(EXIT_SUCCESS);(2)在MATLAB命令窗口输入以下命令编译（假定本机安装的编译器是Microsoft Visual Studio 2005）optsfile = matlabroot binwin32mexoptsmsvc80engmatopts.bat;mex(-f,optsfile,exercise11_4.c)(3)编译完成后，运行exercise11_4.exe5. (1)编辑c源程序exercise11_5.c，代码如下：#include #include #include #include engine.h#define BUFSIZE 256int main() Engine *ep; mxArray *X = NULL, *Y = NULL; char bufferBUFSIZE+1; double x100 ,y100; int n; for( n=0;n100;n+) xn=(n+1)/100.0;yn=(n+1)/100.0; if (!(ep = engOpen(0) fprintf(stderr, nCant start MATLAB enginen); return EXIT_FAILURE; X =