信号与系统课后matlab作业DOC.docx

1、信号与系统课后matlab作业DOCM2-1(1)t=-2:0.001:4;T=2;xt=rectpuls(t-1,T);plot(t,xt)axis(-2,4,-0.5,1.5)图象为：(2)t=sym(t);y=Heaviside(t);ezplot(y,-1,1);gridonaxis(-11-0.11.1)图象为：(3)A=10;a=-1;B=5;b=-2;t=0:0.001:10;xt=A*exp(a*t)-B*exp(b*t);plot(t,xt)图象为：(4)t=sym(t);y=t*Heaviside(t);ezplot(y,-1,3);gridonaxis(-13-0.13.

2、1)图象为：(5)A=2;w0=10*pi;phi=pi/6;t=0:0.001:0.5;xt=abs(A*sin(w0*t+phi);plot(t,xt)图象为：(6)A=1;w0=1;B=1;w1=2*pi;t=0:0.001:20;xt=A*cos(w0*t)+B*sin(w1*t);plot(t,xt)图象为：(7)A=4;a=-0.5;w0=2*pi;t=0:0.001:10;xt=A*exp(a*t).*cos(w0*t);plot(t,xt)图象为：(8)w0=30;t=-15:0.001:15;xt=cos(w0*t).*sinc(t/pi);plot(t,xt)axis(-1

3、5,15,-1.1,1.1)图象为：M2-3（1）functionyt=x2_3(t)yt=(t).*(t=0&t=2&t=3&t=0&t=2&t=3&t0)+0*(t0)+0*(t=0);zi=12;y=lsim(sys,x,t,zi);plot(t,y);title(完全响应)figure;y2=y-y1;plot(t,y2);title(零输入响应)M6-5a=1221;b=12;sys=tf(b,a);pzmap(sys)冲击响应a=1221;b=12;sys=tf(b,a);impulse(sys)阶跃响应a=1221;b=12;sys=tf(b,a);step(sys)频率响应a=

4、1221;b=12;w=linspace(-10,10,20000);H=freqs(b,a,w);plot(w,abs(H)M7-1（1）num=216445632;den=33-1518-12;r,p,k=residuez(num,den)r=-0.01779.4914-3.0702+2.3398i-3.0702-2.3398ip=-3.23611.23610.5000+0.8660i0.5000-0.8660ik=-2.6667（2）num=4-8.86-17.9826.74-8.04;den=1-210665;r,p,k=residuez(num,den)r=1.0849+1.3745

5、i1.0849-1.3745i0.9769-1.2503i0.9769+1.2503ip=2.0000+3.0000i2.0000-3.0000i-1.0000+2.0000i-1.0000-2.0000ik=-0.1237M7-2k=0:10;a=2-13;b=2-1;y1=filter(b,a,x);stem(k,y1)title(零状态响应)figure;h=impz(b,a,k);x=0.5.k;y2=conv(x,h);N=length(y2);stem(0:N-1,y2)title(零输入响应)完全响应y=y1+y2M7-3(1)num=216445632;den=33-1518-12;zplane(num,den)由图可知极点不是都在单位圆内，所以系统不是稳定系统。（2）num=4-8.68-17.9826.74-8.04;den=1-210665;zplane(num,den)由图可知极点不是都在单位圆内，所以系统不是稳定系统。