Approximation of transmittance issue

Hello folks. I have a problem with my matlab code. I need to do approximation but using my filter transmittance which is:

G=(-16.67*s)/(s^2+16.67*s+1)

I got some measured point, i did plot od this, did standard approximation using polyfit and polyvar function and its look like this:

but my teacher said that i cant use polynomial approximation but i have to approximate this function using my filter transmittance instead, but i have no idea how to do this. I would be gratefull for any help.

[Star Strider]

I do not get anything close to that plot using the ‘G’ function you posted. Are you supposed to estimate those constants (-16.67, +16.67) instead of using the ones supplied?

Post your data, and a description of exactly what you want to do.

[Image Analyst]

s = 400 : 50 : 1300;
G=(-16.67*s) ./ (s.^2+16.67*s+1)
plot(s, G, 'r*');
grid on;

And here is the plot:

So, what were you plotting???