def METHOD_NAME(window_ext, sigma=1):
    y, x = np.mgrid[-window_ext:window_ext+1, -window_ext:window_ext+1]
    g = np.zeros(y.shape, dtype=np.double)
    g[:] = np.exp(-0.5 * (x**2 / sigma**2 + y**2 / sigma**2))
    g /= 2 * np.pi * sigma * sigma
    return g