RosettaCodeData/Task/Fast-Fourier-transform/Python/fast-fourier-transform-1.py

12 lines
317 B
Python

from cmath import exp, pi
def fft(x):
N = len(x)
if N <= 1: return x
even = fft(x[0::2])
odd = fft(x[1::2])
return [even[k] + exp(-2j*pi*k/N)*odd[k] for k in xrange(N/2)] + \
[even[k] - exp(-2j*pi*k/N)*odd[k] for k in xrange(N/2)]
print fft([1.0, 1.0, 1.0, 1.0, 0.0, 0.0, 0.0, 0.0])