tsa
ArmaFft.
filter2
filter a time series using fftconvolve3 with ARMA filter
padding of x currently works only if x is 1d in example it produces same observations at beginning as lfilter even without padding.
TODO: this returns 1 additional observation at the end
statsmodels.sandbox.tsa.fftarma.ArmaFft.filter
statsmodels.sandbox.tsa.fftarma.ArmaFft.from_coeffs