w=1;t1=1;clear A;for e=0.2:0.5:3sys0=tf(w*w,[1,2*e*w,w*w]);t=0:0.01:4;step(sys0,t);STR=sprintf('阻尼为%3.2f',e);A(t1)=cellstr(STR);t1=t1+1;hold onendlegend(A);grid
w=1;t1=1;clear A;for e=-0.2:0.5:3sys0=tf(w*w,[1,2*e*w,w*w]);t=0:0.1:8;step(sys0,t);STR=sprintf('阻尼为%3.2f',e);A(t1)=cellstr(STR);t1=t1+1;hold onendlegend(A);grid