GP_UCB _beta is NaN #329
Description
On the first iteration of the optimization when using the GP_UCB acquisition function the iteration is 0. This causes nt to be 0 which causes std::log(nt * pi2 / delta3) to be NaN. This results in all values returned by operator() also being NaN for this iteration. Looking at this reference seems to imply that the iteration (referred to as t in the paper) should start at 1 rather than 0.