Question: how to do a tf in matlab?
Answer: Create the transfer function G ( s ) = s s 2 + 3 s + 2 : num = [1 0]; den = [1 3 2]; G = tf(num,den); num and den are the numerator and denominator polynomial coefficients in descending powers of s. For example, den = [1 3 2] represents the denominator polynomial s2 + 3s + 2.