Pairing the actuators on a periodic mesh for n_act — 5. Panel a: map of the weight w_a given to each actuator. The blue frame is the simulated domain. The red dots are the actuator positions. The green arrows emphasise the different possible pairings for the spacing q = (3, 1). Panel b: map of the weighted number of pairs n_w(q) according to the interactuator spacing q. The blue frame encompasses all the possible positive pairings ∣q∣ on the domain. The green arrow points towards the weighted number of pairs n_w(q=(3, 1)).