octave:16> foo = [1, 2, 1, 0, -1, 0, -1, 3] foo = 1 2 1 0 -1 0 -1 3 octave:17> foof = fft(foo) foof = Columns 1 through 3: 5.00000 + 0.00000i 5.53553 - 1.29289i 0.00000 + 1.00000i Columns 4 through 6: -1.53553 + 2.70711i -5.00000 + 0.00000i -1.53553 - 2.70711i Columns 7 and 8: 0.00000 - 1.00000i 5.53553 + 1.29289i octave:18> foo2 = ifft(foof) foo2 = Columns 1 through 5: 1.0000e+00 2.0000e+00 1.0000e+00 -2.2204e-16 -1.0000e+00 Columns 6 through 8: -2.2204e-16 -1.0000e+00 3.0000e+00