>>
subplot(3,1,3),plot(t,h3t),title('\\sigma=,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
?=0.04，??0.6:?0.3:0
>> syms t s;
>> h1=1/(s-0.04-0.6*i); >> h2=1/(s-0.04-0.3*i); >> h3=1/(s-0.04); >> h1t=ilaplace(h1) h1t =
exp(1/25*t)*(cos(3/5*t)+i*sin(3/5*t)) >> h2t=ilaplace(h2) h2t =
exp(1/25*t)*(cos(3/10*t)+i*sin(3/10*t)) >> h3t=ilaplace(h3) h3t = exp(1/25*t) >> t=-50:0.1:50;
>> h1t =exp(1/25.*t).*(cos(3/5.*t)+i.*sin(3/5.*t)); >> h2t =exp(1/25.*t).*(cos(3/10.*t)+i.*sin(3/10.*t)); >> h3t =exp(1/25*t); >>
subplot(3,1,1),plot(t,h1t),title('\\sigma=0.04,\\omega=0.6'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored. >>
subplot(3,1,2),plot(t,h2t),title('\\sigma=0.04,\\omega=0.3'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored.
>>
subplot(3,1,3),plot(t,h3t),title('\\sigma=0.04,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
?=-0.04:0.02:0.04,?=0.6
>> syms t s;
>> h1=1/(s+0.04-0.6*i); >> h2=1/(s+0.02-0.6*i); >> h3=1/(s-0.6*i); >> h4=1/(s-0.02-0.6*i); >> h5=1/(s-0.04-0.6*i); >> h1t=ilaplace(h1) h1t =
exp(-1/25*t)*(cos(3/5*t)+i*sin(3/5*t)) >> h2t=ilaplace(h2) h2t =
exp(-1/50*t)*(cos(3/5*t)+i*sin(3/5*t)) >> h3t=ilaplace(h3) h3t =
cos(3/5*t)+i*sin(3/5*t) >> h4t=ilaplace(h4) h4t =
exp(1/50*t)*(cos(3/5*t)+i*sin(3/5*t)) >> h5t=ilaplace(h5) h5t =
exp(1/25*t)*(cos(3/5*t)+i*sin(3/5*t)) >> t=-50:0.1:50;
>> h1t =exp(-1/25.*t).*(cos(3/5.*t)+i.*sin(3/5.*t)); >> h2t =exp(-1/50.*t).*(cos(3/5.*t)+i*sin(3/5.*t)); >> h3t =cos(3/5.*t)+i.*sin(3/5*t);
>> h4t =exp(1/50.*t).*(cos(3/5.*t)+i.*sin(3/5.*t)); >> h5t =exp(1/25.*t).*(cos(3/5.*t)+i.*sin(3/5.*t)); >>
subplot(2,3,1),plot(t,h1t),title('\\sigma=-0.04,\\omega=0.6'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored. >>
subplot(2,3,2),plot(t,h2t),title('\\sigma=-0.02,\\omega=0.6'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored. >>
subplot(2,3,3),plot(t,h3t),title('\\sigma=0,\\omega=0.6'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored. >>
subplot(2,3,4),plot(t,h4t),title('\\sigma=0.02,\\omega=0.6'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored. >>
subplot(2,3,5),plot(t,h5t),title('\\sigma=0.04,\\omega=0.6'),xlabel('\\sigma'),ylabel('j\\omega')
Warning: Imaginary parts of complex X and/or Y arguments ignored. >>
?=-0.04:0.02:0.04,?=0
>> syms t s; >> h1=1/(s+0.04); >> h2=1/(s+0.02); >> h3=1/s; >> h4=1/(s-0.02); >> h5=1/(s-0.04);
>> h1t=ilaplace(h1) h1t = exp(-1/25*t) >> h2t=ilaplace(h2) h2t = exp(-1/50*t) >> h3t=ilaplace(h3) h3t = 1
>> h4t=ilaplace(h4) h4t = exp(1/50*t) >> h5t=ilaplace(h5) h5t = exp(1/25*t) >> t=-50:0.1:50; >> h1t =exp(-1/25.*t); >> h2t =exp(-1/50*t); >> h3t =1; >>h4t =exp(1/50*t); >> h5t =exp(1/25*t); >>
subplot(2,3,1),plot(t,h1t),title('\\sigma=-0.04,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
subplot(2,3,2),plot(t,h2t),title('\\sigma=-0.02,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
subplot(2,3,3),plot(t,h3t),title('\\sigma=0,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
subplot(2,3,4),plot(t,h4t),title('\\sigma=0.02,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
subplot(2,3,5),plot(t,h5t),title('\\sigma=0.04,\\omega=0'),xlabel('\\sigma'),ylabel('j\\omega') >>
分析由系统函数零、极点分布决定频率特性代码如下： a图: >> s=0:0.1:5;
>> H=1./(s.*i+1)+1./(s.*i+2); >> plot(s,H)
Warning: Imaginary parts of complex X and/or Y arguments ignored. >> xlabel('\\omega') >> ylabel('|H(j\\omega)|') >> title('a 图幅频特性曲线') b图: >> s=0:0.1:5;
>> H=(i.*s)./((s.*i+1).*(s.*i+2)); >> plot(s,H)
Warning: Imaginary parts of complex X and/or Y arguments ignored. >> xlabel('\\omega') >> ylabel('|H(j\\omega)|') >> title('b 图幅频特性曲线') >> c图: >> s=0:0.1:5;
>> H=(i.*s+1)./((s.*i+2).*(s.*i+3)); >> plot(s,H)
Warning: Imaginary parts of complex X and/or Y arguments ignored. >> xlabel('\\omega')