信号与系统课后matlab作业.doc

M2-1(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);grid onaxis(-1 1 -0.1 1.1)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);grid onaxis(-1 3 -0.1 3.1)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(-15,15,-1.1,1.1)图象为：M2-3（1） function yt=x2_3(t) yt=(t).*(t=0&t=2&t=3&t=0&t=2&t=3&t0)+0*(t0)+0*(t=0);zi=1 2;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=1 2 2 1;b=1 2;sys=tf(b,a);pzmap(sys)冲击响应a=1 2 2 1;b=1 2;sys=tf(b,a);impulse(sys)阶跃响应a=1 2 2 1;b=1 2;sys=tf(b,a);step(sys)频率响应a=1 2 2 1;b=1 2;w=linspace(-10,10,20000);H=freqs(b,a,w);plot(w,abs(H)M7-1（1）num=2 16 44 56 32;den=3 3 -15 18 -12;r,p,k=residuez(num,den)r =-0.0177 9.4914 -3.0702 + 2.3398i -3.0702 - 2.3398ip =-3.2361 1.2361 0.5000 + 0.8660i 0.5000 - 0.8660ik =-2.6667（2）num=4 -8.86 -17.98 26.74 -8.04;den=1 -2 10 6 65;r,p,k=residuez(num,den)r =1.0849 + 1.3745i 1.0849 - 1.3745i 0.9769 - 1.2503i 0.9769 + 1.2503ip =2.0000 + 3.0000i 2.0000 - 3.0000i -1.0000 + 2.0000i -1.0000 - 2.0000ik =-0.1237M7-2k=0:10;a=2 -1 3;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=2 16 44 56 32;den=3 3 -15 18 -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=