%--------------------------
 % @Author: Jingqiao Hu
 % @Date: 2022-01-06 15:33:25
 % @LastEditTime: 2022-01-08 17:37:20

 % specifically for those repeated edges with opposite directions
%--------------------------
function [edges1, ia, ic] = unique_edges(edges0)

    % remove repeated edges with opposite direction
    e0(:,1) = mean(edges0(:,[1,3]), 2);
    e0(:,2) = mean(edges0(:,[2,4]), 2);
    [~, ia, ic] = uniquetol(e0, 'ByRows', true ); 

    edges1 = edges0(ia,:);
end