Hello guys.
I am makig a program to plot the step response of a transfer function. But my program starts defining the numerator and the denominator of the transfer function like the following:
if true
syms s
num_planta=1;
den_planta=s*(s+2);
end
Then I make the fraction
if true
transfer_fnc=num_planta/den_planta
end
Then with that variable I make a code works, but the code does not plot anything. So I decided to do it possible. So I use some techniques but nothing work. I am gonna explain the techniques, so if you can guide me, I will be grateful.
1. Using step(transfer_fcn)
if true
aux_transfer_fcn=transfer_fcn
SS=tf('s')
subs(transfer_fcn,s,SS)
step(aux_transfer_fcn)
end
But matlab says that I cannot substitute a "symbolic" variable to a "tf" variable
2. Making with matrix
if true
[num_transfer_fcn,den_transfer_fcn]=numden(transfer_fcn)
coefs_num_transfer_fcn=coeffs(num_transfer_fcn,s,'all')
coefs_den_transfer_fcn=coeffs(den_transfer_fcn,s,'all')
system=tf(coefs_num_transfer_fcn,coefs_den_transfer_fcn)
end
But matlab does no accept matrices like [1,2,3] only [1 2 3], so I was looking up how to convert but I failed lot of times.
Could you please guide me?
