Compare explorh and explorepd1

explorepd1 with golden section search with 10 iterations
k   fmin           function counter
4   1.480504e-01   14
8   5.252595e-05   291
12  2.879071e-11   498
16  4.060138e-20   724


exploreh
k   fmin           function counter
4   1.480504e-01   14
8   4.516912e-02   28
12  4.640768e-03   40
16  2.446631e-03   54
32  4.394661e-07   96
64  4.366391e-16   211
128 5.714716e-32   440