Fourier transform of ARMA polynomial, zero-padded at end to n
The Fourier transform of the ARMA process is calculated as the ratio
of the fft of the MA polynomial divided by the fft of the AR polynomial.
- Parameters:
- n : int
length of array after zero-padding
- Returns:
fftarma – fft of zero-padded arma polynomial
- Return type:
ndarray