[Nauty] What are the differences between using and not using the -t option in labelg for canonical graph labeling?

[lczhangmath]

Hello, everyone,


I noticed the option -t in labelg. I would like to ask, if I don't use the -t option, will the obtained labels still be canonical? In other words, if I want to get the canonical labeling of a graph, do I have to use the -t option? I noticed that when I don't use the -t option for canonical graph labeling, the graph's labels also change. So, what is labelg doing at this time? Do the obtained labels have some special meaning?


 echo 'E{EG' |showg




Graph 1, order 6.
  0 : 1 2 3 5;
  1 : 0 2;
  2 : 0 1;
  3 : 0 4;
  4 : 3 5;
  5 : 0 4;




echo 'E{EG' |labelg |showg


Graph 1, order 6.
  0 : 4 5;
  1 : 4 5;
  2 : 3 5;
  3 : 2 5;
  4 : 0 1;
  5 : 0 1 2 3;




Use  labelg  -t:
echo 'E{EG' |labelg  -t|showg


Graph 1, order 6.
  0 : 3 4;
  1 : 2 5;
  2 : 1 5;
  3 : 0 5;
  4 : 0 5;
  5 : 1 2 3 4;


Best wishes,
Licheng