1 dimensions: FFTW on vector of size 12 

 2 dimensions: FFTW on vector of size 144 
  Error norm of |x - z1| 106.931

 3 dimensions: FFTW on vector of size 1728 
  Error norm of |x - z1| 107.435

 4 dimensions: FFTW on vector of size 20736 
  Error norm of |x - z1| 109.66