So, I guess the question is how to generate the initial tensors then?
>>> import numpy as np
>>> h = 8
>>> d = .5**.5
>>> fy = np.fft.fftfreq(h,d=d)
>>> fy
array([ 0.        ,  0.1767767 ,  0.35355339,  0.53033009, -0.70710678,
       -0.53033009, -0.35355339, -0.1767767 ])