Relative angle of the heading of the barycenter of the group with the wall.

PDF of the relative angle of the heading of the barycenter of the group with the wall for fish experiments (red line in all panels), model simulations (panels ABC), and robot experiments (panels DEF), compared to the corresponding null models (k = 0, no interaction between individuals) in both simulations and robots (gray line in all panels). Curves for agents (fish model and robots) are in blue and gray, depending on the value of k (see legend in panel B). Interaction strategies involve the k nearest neighbors (panels AD), k random neighbors (panels BE), and the k most influential neighbors (panels CF).