Transfer function using symbol

Question

Peter 2011-10-18

评论： Walter Roberson 2016-9-14

Hello,

is there anyway to create a transfer function with symbol?

like... tf(K*[1 1], [1 1 1]); keeping K as K, with out any value assign to it.

i tried that but it's giving me an error like this:

"Cell contents reference from a non-cell array object."

any idea?

thanks!

Walter Roberson 2016-9-14

Answer 1

Ashikur 2011-10-21

tf cannot take symbols as argument , you cannot do the way you are trying. However you can create your transfer function with all symbols.

s= sym(s)

k = sym(k)

H= (k*s+k)/(s^2+s+1)

Or you could assign some dummy value to k and then change it when your program needs.