 40, f(x) = 7.488881e+02, ||grad||_infty = 1.42e+02
Iter    50, f(x) = 5.919198e+02, ||grad||_infty = 4.48e+00
Iter    60, f(x) = 5.889069e+02, ||grad||_infty = 1.93e+00
Iter    70, f(x) = 5.881156e+02, ||grad||_infty = 8.79e-01
Iter    80, f(x) = 5.877669e+02, ||grad||_infty = 9.43e-01
Iter    90, f(x) = 5.874421e+02, ||grad||_infty = 2.62e+00
Iter   100, f(x) = 5.870874e+02, ||grad||_infty = 2.98e-01
Iter   110, f(x) = 5.869636e+02, ||grad||_infty = 2.99e+00
Iter   120, f(x) = 5.868945e+02, ||grad||_infty