87e-01 f-delta = 7.2e-03
 Iter 29: f = 8.983839e-01 f-delta = 7.6e-03
 Iter 30: f = 9.058962e-01 f-delta = 7.5e-03
 Iter 31: f = 9.126883e-01 f-delta = 6.8e-03
 Iter 32: f = 9.183110e-01 f-delta = 5.6e-03
 Iter 33: f = 9.226911e-01 f-delta = 4.4e-03
 Iter 34: f = 9.260765e-01 f-delta = 3.4e-03
 Iter 35: f = 9.288145e-01 f-delta = 2.7e-03
 Iter 36: f = 9.311877e-01 f-delta = 2.4e-03
 Iter 37: f = 9.333745e-01 f-delta = 2.2e-03
 Iter 38: f = 9.354731e-01 f-delta = 2.1e-03
 Iter 39: f = 9.375329e-01 f-delta = 