I want to use inverse laplace with tf function. How can I do it? I take an error in matlab when ı use code like below.

A=[-2 0 ; 0 -1]
B=[1;2]
C=[1 1]
D=0;
P=ss(A,B,C,D)
syms s 
F=tf(P)
ilaplace(F)

Answer 1

[Star Strider]

Try this:

A=[-2 0 ; 0 -1]
B=[1;2]
C=[1 1]
D=0;
P=ss(A,B,C,D)

syms s t 
F=tf(P)

num = poly2sym(F.Numerator, s)
den = poly2sym(F.Denominator, s)
f(t) = ilaplace(num/den)

figure
fplot(f, [0,10])
grid

producing:

num =
3*s + 5
 
den =
s^2 + 3*s + 2
 
f(t) =
2*exp(-t) + exp(-2*t)

and the plot.

[caglar karabacak]

thank you it works.:))

[Star Strider]

As always, my pleasure!

Answer 2

[madhan ravi]

https://in.mathworks.com/matlabcentral/answers/415409-how-to-get-a-inverse-laplace-of-a-tf#answer_333322

[caglar karabacak]

Thank you I tried this code. My function doesnt have num and den varialbles. I tried to convert this code for my function but it doesnt work please help me .