Research Article

Geometric Generalisation of Surrogate Model-Based Optimisation to Combinatorial and Program Spaces

Table 1

Results for SMBO, an evolutionary algorithm (EA), a (1 + 1) evolutionary algorithm ((1 + 1) EA), and random search (RS) on the NK-landscape benchmark for all combinations of = 2, 3, 4, 5 and = 10, 15, 20, 25.

(optimum) SMBO EA (1 + 1) EA RS
Best Average Best Average Best Average Best Average

n = 10
2 (0.704) 0.704 0.702 0.704 0.686 0.698 0.675 0.704 0.649
3 (0.794) 0.794 0.775 0.794 0.724 0.745 0.705 0.794 0.724
4 (0.787) 0.787 0.755 0.787 0.725 0.787 0.714 0.787 0.727
5 (0.810) 0.810 0.762 0.727 0.706 0.810 0.729 0.810 0.718

n = 15
2 (0.743) 0.743 0.742 0.714 0.693 0.681 0.628 0.714 0.674
3 (0.738) 0.738 0.718 0.706 0.678 0.706 0.622 0.717 0.677
4 (0.747) 0.747 0.721 0.711 0.685 0.705 0.646 0.710 0.680
5 (0.760) 0.758 0.737 0.749 0.711 0.728 0.672 0.757 0.700

n = 20
2 (0.729) 0.729 0.726 0.718 0.689 0.668 0.613 0.711 0.673
3 (0.777) 0.777 0.767 0.761 0.718 0.639 0.606 0.777 0.706
4 (0.775) 0.775 0.747 0.731 0.708 0.676 0.640 0.707 0.684
5 (0.766) 0.761 0.744 0.745 0.710 0.709 0.637 0.721 0.684

n = 25
2 (0.753) 0.753 0.747 0.727 0.698 0.679 0.590 0.701 0.673
3 (0.798) 0.798 0.781 0.742 0.727 0.666 0.607 0.749 0.698
4 (0.775) 0.762 0.743 0.750 0.714 0.639 0.595 0.695 0.679
5 (0.774) 0.756 0.736 0.751 0.713 0.705 0.622 0.722 0.676

The best (maximum) and average values of the best solution found by each algorithm are given for 50 runs.
Bold numbers are the highest maxima and italic numbers are the second highest maxima.