Analyzing the Runtime of the Gene-pool Optimal Mixing Evolutionary Algorithm (GOMEA) on the Concatenated Trap Function
Yukai Qiao, Marcus Gallagher
TL;DR
This work provides the first runtime analysis of GOMEA on the concatenated trap function, a modular, deceptive optimization benchmark. By proving that a truthful FOS enables efficient recombination of optimal subsolutions, the authors derive an upper bound of $O(m^{3}2^{k})$ on the expected runtime, achieving a substantial speedup over the $(1+1)$ EA’s $O(\ln{m}(mk)^{k})$. They validate the theory with experiments showing that, for a suitably large population $\mu=cm2^{k}$, GOMEA reliably finds the global optimum with high probability, and that the Optimal Mixing operator is key to preserving building blocks. The continuation work extends these results to generalized trap functions, highlighting the role of the optimal-region probability $p_{*}$ and offering bounds that scale as $O(\frac{1}{p_{*}}m^{3})$, with empirical evidence supporting robustness across parameter choices. Overall, the paper advances theoretical understanding of linkage learning and informed variation in modular, deceptive optimization problems, with implications for complex real-world domains that exhibit subfunction structure.
Abstract
The Gene-pool Optimal Mixing Evolutionary Algorithm (GOMEA) is a state of the art evolutionary algorithm that leverages linkage learning to efficiently exploit problem structure. By identifying and preserving important building blocks during variation, GOMEA has shown promising performance on various optimization problems. In this paper, we provide the first runtime analysis of GOMEA on the concatenated trap function, a challenging benchmark problem that consists of multiple deceptive subfunctions. We derived an upper bound on the expected runtime of GOMEA with a truthful linkage model, showing that it can solve the problem in $O(m^{3}2^k)$ with high probability, where $m$ is the number of subfunctions and $k$ is the subfunction length. This is a significant speedup compared to the (1+1) EA, which requires $O(ln{(m)}(mk)^{k})$ expected evaluations.
