[Nauty] genbg and res/mod

[Jernej Azarija]

Hello!

Thanks for this! It turns out that Ubuntu is shipping version 2.4
which apparently does not work properly. mod/res Indeed works fine on
a compiled version of nauty 2.5.

Best,

Jernej

On Wed, Nov 25, 2015 at 9:56 PM, Jernej Azarija
<jernej.azarija at gmail.com> wrote:
> Hello!
>
> Thanks for this! It turns out that Ubuntu is shipping version 2.4
> which apparently does not work properly. mod/res Indeed works fine on
> a compiled version of nauty 2.5.
>
> Best,
>
> Jernej
>
> On Wed, Nov 25, 2015 at 9:24 PM, Sean A. Irvine <sairvin at gmail.com> wrote:
>> Which version do you have?  It seems to be working fine for me (with 2.5):
>>
>> $ genbg -u 6 6 0/1000000
>>>A genbg n=6+6 e=0:36 d=0:0 D=6:6  class=0/1000000
>>>Z 0 graphs generated in 0.00 sec
>> $ genbg -u 6 6 1/1000000
>>>A genbg n=6+6 e=0:36 d=0:0 D=6:6  class=1/1000000
>>>Z 50 graphs generated in 0.00 sec
>> $ genbg -u 6 6
>>>A genbg n=6+6 e=0:36 d=0:0 D=6:6
>>>Z 251610 graphs generated in 0.25 sec
>>
>> On 26 November 2015 at 09:10, Jernej Azarija <jernej.azarija at gmail.com> wrote:
>>> Hello!
>>>
>>> I need to use genbg quite a bit and hence would like to be able to
>>> split graph generation into smaller instances.
>>>
>>> Based on what is written in geng.c I got the idea that using different
>>> values of mod should give disjoint sets of graphs. Am I correct? The
>>> reason that I am asking this is because it seems that is not the case:
>>>
>>> $ genbg -u 6 6 0/1000000
>>>>A genbg n=6+6 e=0:36 d=0:0 D=6:6  class=0/1000000
>>>>Z 251610 graphs generated in 0.21 sec
>>> $ genbg -u 6 6 1/1000000
>>>>A genbg n=6+6 e=0:36 d=0:0 D=6:6  class=1/1000000
>>>>Z 1 graphs generated in 0.08 sec
>>>
>>> as well as
>>>
>>> $ genbg -u 6 6
>>>>A genbg n=6+6 e=0:36 d=0:0 D=6:6
>>>>Z 251610 graphs generated in 0.22 sec
>>>
>>> So I often encounter that some value of res will in fact give the
>>> entire class of graphs and the other values overlap graphs.
>>>
>>> $ genbg -u 7 7 0/10
>>>>A genbg n=7+7 e=0:49 d=0:0 D=7:7  class=0/10
>>>>Z 3366061 graphs generated in 8.36 sec
>>> $ genbg -u 7 7 1/10
>>>>A genbg n=7+7 e=0:49 d=0:0 D=7:7  class=1/10
>>>>Z 33642660 graphs generated in 21.16 sec
>>>
>>> $ genbg -u 7 7
>>>>A genbg n=7+7 e=0:49 d=0:0 D=7:7
>>>>Z 33642660 graphs generated in 21.01 sec
>>>
>>> The same thing seems to happen no matter what value of mod I pick.
>>>
>>> $ genbg -u 7 7 1/1000000
>>>>A genbg n=7+7 e=0:49 d=0:0 D=7:7  class=1/1000000
>>>>Z 33642660 graphs generated in 21.16 sec
>>> $ genbg -u 7 7 100/1000000
>>>>A genbg n=7+7 e=0:49 d=0:0 D=7:7  class=100/1000000
>>>>Z 33642660 graphs generated in 19.38 sec
>>>
>>>
>>> Hence it takes much more time to use res/mod than simply avoiding it.
>>> Am I missing something or is there something wrong with the above
>>> behavior of genbg?
>>>
>>> Best,
>>>
>>> Jernej
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