Question

求助：matlab中用lsim求任意输入的响应曲线时报错。

n=[0.01,3];d=[1.33/10^4,0.028,3];
sys=tf(n,d);
t=0:0.005:2;
u=cos(t)/sin(t);
[y,t]=lsim(sys,u,t);plot(t,y);hold;plot(t,u,'r')

Error using ==> lti.lsim at 81
When simulating the response to a specific input signal, the input data U must be a matrix of real values with at least two
rows (samples) and without any NaN or Inf.
Error in ==> test at 6
[y,t]=lsim(sys,u,t);plot(t,y);hold;plot(t,u,'r')

我把输入改成u=cos(t)+sin(t);就完全没问题。但是乘或除就报错。为啥？

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Answer 1

你的u里面有无穷大的数，不能仿真