Operate coefficients in Symbolic expressions

Hi,

I would like to know how to operate the coefficients in a symbolic expression.

Thanks!

Example:

syms s k kc
G_s=k/(s^3+6*s^2+10*s);
D_s=kc*(s+2)/(s+9.067);

t_s=(G_s*D_s)/(1+G_s*D_s);
vpa(simplify(t_s),5)

Result:

Desired result:

Answer 1

[Ameer Hamza]

Maybe there is an easy option, but something like this will work

syms s k kc
G_s=k/(s^3+6*s^2+10*s);
D_s=kc*(s+2)/(s+9.067);
t_s=(G_s*D_s)/(1+G_s*D_s);
[n,d] = numden(t_s);
a = gcd(coeffs(n));
vpa(simplify((n/a)/(d/a)))

[Ignacio Fidalgo]

Thank you very much for your answer, but as you've said, i'm looking for an easier option. Maybe one already implemented in matlab, since this is a very simple example but it can get harder.

[Walter Roberson]

There is no method implemented in MATLAB for this purpose. You are fighting against the internal rules for representation of ratios.

You could probably replace the last line with

vpa(n/a)/vpa(d/a)