Why is the function to get the nearest distance in MPC controller in the following form?

[TheDarkKnight1998]

Hello, I'm learning to use your framework, some of which MPC didn't understand

def _get_closest_dist(self, pred, pos_veh_front): #TODO
closest_dist = np.full(len(pred), float('Inf'))#
if pos_veh_front < pred[0][0]: # before the vehicle reach the crossing point
for i in range(len(pred)):
lat_max = pred[i, 1] + pred[i, 2] # sy + vx???
lat_min = pred[i, 1] - pred[i, 2]

            if 0 < lat_min < self.W_lane or 0 < lat_max < self.W_lane or \
                    (0 < lat_min and lat_max < self.W_lane) or (lat_min < 0 and self.W_lane < lat_max):  #
                lon_min = pred[i, 0] - pred[i, 2] #sx -vx ??
                closest_dist[i] = lon_min

    return closest_dist

Can you explain it?

[TheDarkKnight1998]

Index 2 should be 4, right?