[Nauty-list] shortg outputs

[Kenneth Joseph Ryan]

Hi,

I use shortg -k to reduce files of graphs. The input files in our applications can be rather large (tens of millions of bipartite undirected graphs all with the same number of vertices), and the reductions are typically an order of magnitude or more.

For a new method to our problem type, each input file will be presorted by a "secondary criterion."  I ultimately need to produce an output file which

1)      contains the isomorphic copy within each class that occurs "first" in the input file and

2)      the output file needs to preserve input file order.
At this point, I realize that I could use the class output produced by shortg -vu and then extract the needed subset of input graphs through a separate program, but am hoping to find a direct, more timely solution because the reductions are so large.

I focused on reading the manual and then even tried my hand at reading nauty code but with no luck, so I moved onto simple examples. Through simple examples I already know that 2) does not happen directly, but I have not constructed an example where 1) did not hold. Does 1) always hold? Is there a setting (or some slick approach) such that I can get 1) AND 2) directly?

Thanks in advance for your time,
----
Ken Ryan, Associate 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<mailto:kjryan at bgsu.edu>
Web: http://www.cba.bgsu.edu/faculty_staff/ryan/



----
Ken Ryan, Associate 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/

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