[H, f1, f2] = freqz2(h, n1, n2) returns H, the n2-by-n1 frequency response of h, and the frequency vectors f1 (of length n1) and f2 (of length n2). h is a two-dimensional FIR filter, in the form of a computational molecule. f1 and f2 are returned as normalized frequencies in the range -1.0 to 1.0, where 1.0 corresponds to half the sampling frequency, or π radians.
So if you put n1 = 1 and n2= 1, you should get a 1-by-1 frequency response H. Hope that helps.
