[Nauty-list] shortg question

[Ken Ryan]

Hi,

 From a set of input graphs, I need to (1) remove isomorphs, (2) keep the 
same labelling as the inputs, and (3) know for each output graph the 
corresponding input graph.  If I use

shortg -kv

(1) and (2) are done.  As for (3),

shortg -help

describes the example

   23 : 30 154 78

under the -k option where inputs 30, 154, and 78 were isomorphic and 
produced output 23.  Is it the case (in general) that shortg is programmed 
such that the output is always the first listed input, i.e., output 23 is 
input 30 in the example?  I could go back to my inputs and use the 
information from -k to obtain a subset such that I have (1)-(3), but want 
to avoid this extra step if possible.  If the answer to my question is no 
and there is another way to get (1)-(3) directly, please advise.

Thanks,

Ken Ryan, Assistant Professor
Applied Statistics and Operations Research
Bowling Green State University
Bowling Green, Ohio 43403-0267
Phone: (419)372-2958
Fax: (419)372-2875
Email: kjryan at bgsu.edu
Web: http://www.cba.bgsu.edu/faculty_staff/ryan/