MATLAB: Can I preserve adding order when calling graph/addedge

graphgraph theorytable

Hi when calling graph/addedge. The added edge are re-ordered from the adding order. For example:
>> g = graph;
>> g = graph;
>> g = g.addedge(5, 6);
>> g = g.addedge(1, 2);
>> g.Edges
ans =
  2×1 table
    EndNodes
    ________
     1    2 
     5    6
Is there a way to avoid this re-order?
This question comes from a requirement that I would like to remember indices of some edges for quick access. However, if calling addedge the indices will be then dis-ordered. It is not suitable to look up edge by EndNodes in my case because the graph can contain multi-edges.

Best Answer

The edges in a graph are always presented in the same order (sort first by source node, secondarily be target node). You can maintain an index into the previous numbering of the edges by adding a new property that tracks this:
>> g = graph;
>> g = addedge(g, 5, 6, 1);
>> g = addedge(g, 1, 2, 2);
>> g.Edges
ans =
  2×2 table
    EndNodes    Weight
    ________    ______
     1    2       2   
     5    6       1
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