[Nauty-list] Issue with geng and showg

keith.briggs at bt.com keith.briggs at bt.com
Fri May 6 01:53:19 EST 2011

When I do "geng -help" the -n option is not documented.  Why does geng accept it?
The following works perfectly:

geng  4 4:4  | showg

From: nauty-list-bounces at cs.anu.edu.au [nauty-list-bounces at cs.anu.edu.au] On Behalf Of Marcus Nunes [man238 at psu.edu]
Sent: 05 May 2011 16:28
To: Nauty List
Subject: [Nauty-list] Issue with geng and showg

Hi there

I'm trying to use geng.c to generate and save my graphs. When I run

./geng -n 4 4:4  result.g6

I get

>A ./geng -d0D3 n=4 e=4
>Z 2 graphs generated in 0.00 sec

But, when I try to use showg to read my output, I get

./showg result.g6
>E showg: illegal character

It seems geng is not generating the graphs correctly. For the example above, I have


which, compared to examples I found on internet, doesn't make sense at all.

Do you have some help to offer to me? I'm using Mac OS 10.6.7, gcc 4.2.1 and I have no experience with C. I want to generate the graphs and work with them in R.

Marcus Nunes
man238 at psu.edu<mailto:man238 at psu.edu>

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