1 2 1 dimensions: FFTW on vector of size 5 3 Error norm of |x - z1| 2.77388 4 5 2 dimensions: FFTW on vector of size 25 6 Error norm of |x - z1| 21.1472 7 8 3 dimensions: FFTW on vector of size 125 9 Error norm of |x - z1| 91.4129 10 11 4 dimensions: FFTW on vector of size 625 12 Error norm of |x - z1| 471.544 13