scipy.signal.freqs

scipy.signal.freqs(b, a, worN=None, plot=None)

Compute frequency response of analog filter.

Given the numerator (b) and denominator (a) of a filter compute its frequency response.

b[0]*(jw)**(nb-1) + b[1]*(jw)**(nb-2) + ... + b[nb-1]

H(w) = ——————————————————–

a[0]*(jw)**(na-1) + a[1]*(jw)**(na-2) + ... + a[na-1]

Parameters:

b : ndarray

numerator of a linear filter

a : ndarray

numerator of a linear filter

worN : {None, int}, optional

If None, then compute at 200 frequencies around the interesting parts of the response curve (determined by pole-zero locations). If a single integer, the compute at that many frequencies. Otherwise, compute the response at frequencies given in worN.

Returns:

w : ndarray

The frequencies at which h was computed.

h : ndarray

The frequency response.