Simple Filter representation in Matlab Suppose I have an IIR filter in the $z$-domain in the following form:
$$
H\left(z\right)=\frac{1}{1-0.2z^{-1}-0.1z^{-2}}
$$
How do I represent this in MATLAB?
I am pretty sure if I just listed the coefficients as H = [1 -0.2 -0.1];
this would be considered wrong. Can somebody help me with this please?
You have to define numerator and denominator polynomials. In your case you have

b = 1;
a = [1,-0.2, -0.1];