function [HvelsLeft, VvelsLeft, HvelsRight, VvelsRight] = split_centroids(Centroids)
% given a list of three centroids, figure out which is which
% once initially determined, continue tracking them by always
% choosing as the next corresponding the centroid the one that
% is closest to the one under consideration

curCentroids = Centroids(1:3, :);
[CMin IMin] = min(curCentroids(1:3, 1)); %left hand
[CMax IMax] = max(curCentroids(1:3, 1)); %right hand

LastLeft = curCentroids(IMin, :);
LastRight = curCentroids(IMax, :);

[rows cols] = size(Centroids);

HvelsLeft = [];
VvelsLeft = [];
HvelsRight = [];
VvelsRight = [];

for i = 4:3:rows %start at 4, step by 3, go to cols
    curCentroids = Centroids(i:(i+2), :);
    distancesLeft = [LastLeft;LastLeft;LastLeft] - curCentroids;
    distancesRight = [LastRight;LastRight;LastRight] - curCentroids;
    
    distsL = sqrt((distancesLeft(:,1).^2) + (distancesRight(:,2).^2));
    distsR = sqrt((distancesRight(:,1).^2) + (distancesRight(:,2).^2));
    
    [LMin iL] = min(distsL);
    [RMin iR] = min(distsR);
    CurLeft = curCentroids(iL, :);
    CurRight = curCentroids(iR, :);
    
    
    HvelsLeft = [HvelsLeft, CurLeft(1) - LastLeft(1)];
    VvelsLeft = [VvelsLeft, CurLeft(2) - LastLeft(2)];
    HvelsRight = [HvelsRight, CurRight(1) - LastRight(1)];
    VvelsRight = [VvelsRight, CurRight(2) - LastRight(2)];
    
    LastLeft = CurLeft;
    LastRight = CurRight;
end