Branin's function in [-5, 10] x [0, 15]: three global minima of 0.397887
6 points of a Latin hypercube, then a point per step by log-EI on a Gaussian process
evaluation         x1         x2            f     f - f*
         1  -2.094023  11.483177     7.711008      7.3e0
         2   9.566534   8.178619    31.646772      3.1e1
         3   1.779636   0.917823    15.079196      1.5e1
         4   3.116619   3.157308     1.145222     7.5e-1
         5  -4.412273   6.407455    90.516029      9.0e1
         6   5.122378  13.384503   161.386238      1.6e2
         7   3.802460   1.091098     2.945049      2.5e0
         8   5.754346   1.947420    18.976188      1.9e1
         9  -4.083638  13.352664     6.045107      5.6e0
        10  -2.253838  14.243188    19.938494      2.0e1
        11   4.727562   5.297559    25.625619      2.5e1
        12  10.000000   3.801580     2.580940      2.2e0
        13  10.000000   0.000000    10.960889      1.1e1
        14   0.890363   6.322041    18.719724      1.8e1
        15  -5.000000  15.000000    17.508300      1.7e1
        16   3.235854   2.197541     0.440540     4.3e-2
        17   9.097758   2.736199     1.180535     7.8e-1
        18   9.790067   2.374804     1.212532     8.1e-1
        19   8.300793   0.000000     8.707440      8.3e0
        20   2.863389   2.491949     0.767187     3.7e-1
        21  -3.154554  12.141734     0.425733     2.8e-2
        22  -3.156264  12.562523     0.462544     6.5e-2
        23   9.492983   2.838771     0.513627     1.2e-1
        24  -3.153503  12.328721     0.399197     1.3e-3
        25   9.363618   2.249384     0.446294     4.8e-2
        26  -3.001106  11.914866     0.493115     9.5e-2
        27   3.134020   2.378650     0.407715     9.8e-3
        28   3.208078   2.505644     0.498582     1.0e-1
        29   9.424509   2.484571     0.397984     9.6e-5
        30  -3.833119  15.000000     3.606387      3.2e0
the model of the 30 evaluations, its mean minimized by L-BFGS-B from the best point:
(9.422974, 2.475867): predicted 0.397917, evaluated 0.397909, 2.1e-5 above the minimum at (9.424778, 2.475000)
31 evaluations: the best 2.1e-5 above the global minimum
