FFT Shift

import matplotlib.pyplot as plt
import numpy as np
N = 128
x = np.linspace(-5, 5, N)
y = np.exp(-x**2)
y_fft = np.fft.fftshift(np.fft.fft(y).real)
plt.plot(x, y_fft)
[<matplotlib.lines.Line2D at 0x10d828c18>]
plt.show()

png