hilbert_inverse.adb accuracy test
IEEE 64-bit floating point, Hilbert vs random matrix
for N by N matrices, N=2, 4, 8, 16, 32, 64, 126, 256

N= 2, norm= 5.00000000000000E-01, mindiag= 2.77777777777778E-02
     avgerr= 0.00000000000000E+00, maxerr= 0.00000000000000E+00
random  norm= 9.57703478614662E-01, mindiag= 3.43126544107735E-01
     avgerr= 1.11022302462516E-16, maxerr= 2.22044604925031E-16

N= 4, norm= 5.00000000000000E-01, mindiag= 3.40136054421595E-05
     avgerr= 1.49213974509621E-13, maxerr= 4.83169060316868E-13
random  norm= 8.78224828689464E-01, mindiag= 3.07400787317013E-01
     avgerr= 9.88792381306780E-17, maxerr= 6.10622663543836E-16

N= 8, norm= 5.00000000000000E-01, mindiag= 7.70063725548032E-11
     avgerr= 8.17485670268070E-08, maxerr= 6.72487658448517E-07
random  norm= 9.50140439416347E-01, mindiag= 2.85028269325517E-01
     avgerr= 1.98395445037691E-16, maxerr= 1.34614541735800E-15

N= 16, norm= 5.00000000000000E-01, mindiag= 1.38929828320648E-17
     avgerr= 8.22267382740392E-01, maxerr= 9.06417759880424E+00
random  norm= 9.98965688514973E-01, mindiag= 2.13256146691945E-02
     avgerr= 3.42109153506076E-15, maxerr= 2.55739873722405E-13

N= 32, norm= 5.00000000000000E-01, mindiag= 2.51620816179365E-18
     avgerr= 2.92239094468823E+00, maxerr= 9.28515417873859E+01
random  norm= 9.99062706250261E-01, mindiag= 2.66942573115051E-01
     avgerr= 6.63972530800836E-16, maxerr= 9.33194493901723E-15

N= 64, norm= 5.00000000000000E-01, mindiag= 5.84627620370273E-19
     avgerr= 8.09338344584467E+00, maxerr= 1.37222497192025E+03
random  norm= 9.98923463280743E-01, mindiag= 1.65117409510912E-01
     avgerr= 1.75048357778857E-15, maxerr= 1.58206781009085E-14

N= 128, norm= 5.00000000000000E-01, mindiag= 8.08057018267399E-19
     avgerr= 1.11581809358086E+01, maxerr= 4.63998453617096E+02
random  norm= 9.99971685931073E-01, mindiag= 3.65391502673622E-02
     avgerr= 2.06410062479718E-14, maxerr= 8.04873528936767E-13

N= 256, norm= 5.00000000000000E-01, mindiag= 6.30280034566471E-20
     avgerr= 3.88699966200056E+01, maxerr= 4.49170629262924E+03
random  norm= 9.99970950186239E-01, mindiag= 9.27201229859621E-01
     avgerr= 3.20751142961347E-15, maxerr= 1.53597707469588E-12

hilbert_inverse ends