Before revision: Given a trajectory T = {P1, P2, P3, ..., Pn}, where Pt is the 2D position at time t. For each pair of positions Pt and P<subt + 11</sub> , calculate the direction angle θ(t, t+1).
After revision: Given a trajectory T = {P1, P2, P3, ..., Pn}, where Pt is the 2D position at time t. For each pair of positions Pt and Pt + 1 , calculate the direction angle θ(t, t+1).