How can I calculate AR coefficients from zero-poles?

I all, I've to calculate AutoRegressive Model coefficients starting from zeros and poles values. There is any command that can do this? I've tried with

[b,a]=zp2tf(1,p,1);

but it seems to be uncorrect.

Answer 1

[Azzi Abdelmalek]

%example, 
z=1   % one zero
p=[-1 -2], % two poles
model=tf(poly(z),poly(p))
[b,a]=tfdata(model,'v')

[Fa']

Thank you Azzi. I've another question: How can I do If I have to generate a signal using this AR model with White Noise as input?

[Azzi Abdelmalek]

use

 lsim(model,u,t)

 % t is time
 % u yuour white noise