signal

A few functions from scipy.signal were implemented with mpmath to investigate the numerical accuracy of the filter design and frequency response calculations.

butter_bp(n, wlo, whi)	Bandpass Butterworth filter design.
butter_lp(n, Wn)	Lowpass Butterworth digital filter design.
butter_lp_ord(wp, ws, deltap, deltas[, fs])	(deltap and deltas are not in dB!)
cheby1_lp(N, rp, Wn)	Chebyshev Type I lowpass digital filter design.
freqz(b[, a, worN])	Frequency response of a filter in (b, a) format (i.e.
poly_from_zeros(z)	Convert the zeros of a polynomial to the coefficients.
zpkfreqz(z, p, k[, worN])	Frequency response of a filter in zpk format.