信号与系统实验参考程序.doc

实验一：内容1A=ones(3,2)B=zeros(3,2)C=rand(3,2)D=randn(3,2)E=eye(3)内容2x=input(x=) y,z=qiuhe(x); %函数见qiuhe.mfprintf(N个数总和为),y fprintf(N个数平均为),z函数求和function y,z = qiuhe(x)m,n=size(x); if m = 1 M=n; end y = sum(x); z = sum(x)/n;内容3t=0:0.1:30; y1=sin(t); y2=exp(-0.1.*t).*sin(t+1);subplot(2,1,1),plot(t,y1),gridsubplot(2,1,2),plot(t,y2),grid实验二：内容1%产生单位冲激信号clear all;t0=0;t1=1;dt=0.05;t=0:0.05:5;st=length(t);n1=floor(t1-t0)/dt);x1=zeros(1,st);x1(n1)=1/dt;subplot(4,1,1),stairs(t-0.95,x1),gridaxis(-1,4,-1,22)%产生单位阶跃信号x2=zeros(1,n1-1),ones(1,st-n1+1);subplot(4,1,2),stairs(t-0.95,x2),gridaxis(-1,4,-0.1,1.1)%产生周期的三角波clear all;t=-4*pi:0.01:4*pi;a=sawtooth(t,0.5);subplot(4,1,3),plot(t,a),axis(-4*pi,4*pi,-1.1,1.1),grid%产生周期的方波b=square(t,50);subplot(4,1,4),plot(t,b),axis(-4*pi,4*pi,-1.1,1.1),grid内容2：a=input(输入方程左边系数向量aa1,a2,.=);n=length(a)-1;y0=input(输入初始条件向量 y0y0,dy0,.=);p=roots(a); v=rot90(vander(p); c=v/y0; dt=0.2; tf=8; t=0:dt:tf;y=zeros(1,length(t);for k=1:n y=y+c(k)*exp(p(k)*t);end;plot(t,y),grid;内容3：a=input(输入方程左边系数向量 aa1,a2,.=);b=input(输入方程右边系数向量 bb1,b2,.=);u=input(输入信号 u(t)=);dt=0.2; tf=8; t=0:dt:tf;r,p,k=residue(b,a); h=zeros(1,length(t);for i=1:length(a)-1; h=h+r(i)*exp(p(i)*t);endsubplot(2,1,1),plot(t,h),gridy=conv(u,h);subplot(2,1,2),plot(t,y(1:length(t),grid实验三：内容1t=0:0.01:2*pi; y=sin(t);plot(t,y),grid,hold ony1=sin(t)+sin(3*t)/3;plot(t,y1)y2=sin(t)+sin(3*t)/3+sin(5*t)/5;plot(t,y2)y3=sin(t)+sin(3*t)/3+sin(5*t)/5+sin(7*t)/7;plot(t,y3)y4=sin(t)+sin(3*t)/3+sin(5*t)/5+sin(7*t)/7+sin(9*t)/9;plot(t,y4)内容2：clear,tf=1; N=256;dt=1/N;t=-N+1:N*dt;f=zeros(1,N/2),ones(1,N),zeros(1,N/2);wf=50;nf=64;w1=linspace(0,wf,nf);dw=wf/(nf-1);f1=f*exp(-j*t*w1)*dt;w=-fliplr(w1),w1(2:nf);f2=-fliplr(f1),f1(2:nf);subplot(1,2,1),plot(t,f,linewidth,1.5),axis(-1,1,-0.1,1.1),gridsubplot(1,2,2),plot(w,abs(f2),linewidth,1.5),grid实验四：内容1%计算传递函数fA=5,10;gA=5,2,1;fB=4;gB=1,1,0;%串联fh1=conv(fA,fB); gh1=conv(gA,gB);disp(串联后传递函数)printsys(fh1,gh1,s)%并联fh2=polyadd(conv(fA,fB),conv(gA,gB); gh2=conv(gA,gB); disp(并联后传递函数)printsys(fh2,gh2,s)%反馈后传递函数fh3=conv(fA,gB); gh3=polyadd(conv(fA,fB),conv(gA,gB);disp(反馈后传递函数)printsys(fh3,gh3,s)%画零极点图num=input(输入分子系数 sum=a1,a2,.=);den=input(输入分母系数 den=b1,b2,.=);z,p=tf2zp(num,den);zplane(z,p),grid内容2：实验五：内容1：cleart=linspace(0,2*pi,1001); u=0.5,0.5; u1=cos(5*t); u2=cos(100*t); u31=u(1)*cos(95*t); u32=u(2)*cos(105*t);u3=u31+u32;subplot(3,1,1),plot(t,u1),gridsubplot(3,1,2),plot(t,u2),gridsubplot(3,1,3),plot(t,u3),grid内容2：实验六：内容1%信号通过带通滤波器cleart=linspace(0,2*pi,1001);w=99,100,101;u=0.5,1,0.5;b=2,0;a=1,2,10001;u1=u*cos(w*t+angle(u)*ones(1,1001);h=freqs(b,a,w);%画频率响应figure(1)subplot(2,1,1),plot(w,abs(h),gridsubplot(2,1,2),plot(w,angle(h),gridu21=abs(u(1)*h(1)*cos(99*t+angle(u(1)*h(1);u22=abs(u(2)*h(2)*cos(100*t+angle(u(2)