a=1 b=0.5 N=3 tau=1: |dualR-Op| spread 1.38e-40 (b^2/a = 0.25, values 0.25);  |dualP-Op| spread 0.225;  max |dualP_i - midpoint(dualR)| (best shift) 9.81e-41
a=1 b=0.62 N=5 tau=2: |dualR-Op| spread 1.49e-40 (b^2/a = 0.3844, values 0.3844);  |dualP-Op| spread 0.372;  max |dualP_i - midpoint(dualR)| (best shift) 9.26e-41
a=1 b=0.8 N=6 tau=1: |dualR-Op| spread 8.04e-41 (b^2/a = 0.64, values 0.64);  |dualP-Op| spread 0.191;  max |dualP_i - midpoint(dualR)| (best shift) 3.25e-41
a=1.7 b=0.3 N=8 tau=3: |dualR-Op| spread 1.1e-37 (b^2/a = 0.05294117647, values 0.05294117647);  |dualP-Op| spread 0.0529;  max |dualP_i - midpoint(dualR)| (best shift) 5.41e-38
