“…In many applications of swarm robotics, the swarm must spread across a domain according to a target distribution in order to achieve its goal. Some examples are in surveillance and area coverage [8,20,23,31], achieving a heterogeneous target distribution [4,10,14,16,17,34,41], and aggregation and pattern formation [28][29][30][36][37][38]. Despite the importance of assessing performance, some studies such as [28,29,34,38,41] rely only on qualitative methods such as visual comparison.…”