On Tuesday, September 6, 2016 at 9:29:33 AM UTC, Jihoon Seo wrote:
>
>
> Hi
> I generated some directed graphs using `geng` and `directg`, the utilities
> included in Nauty <http://pallini.di.uniroma1.it/>.
>
> ./geng 5 | ./directg
>
>
> The generated graphs look like:
>
>> &D?????
>> &DA????
>> &DA??G?
>> &DAC???
>> &DA??C?
>> &D???K?
>> &DAC?G?
>> &DA??K?
>> &DAC?K?
>> &DACG??
>
>
> And here is the description of `digraph6` format (from Nauty user's guide
> <http://pallini.di.uniroma1.it/nug26.pdf>)
> ------------------------------
>
>> Data type:
>> simple directed graphs (allowing loops) of order 0 to 68719476735.
>> Optional Header:
>> >>digraph6<< (without end of line!)
>> File name extension:
>> .d6
>> One graph:
>> Suppose G has n vertices. Write the adjacency matrix of G
>> as a bit vector x of length n^2, row by row.
>> Then the graph is represented as '&' N(n) R(x).
>> The character '&' (decimal 38) appears as the first character.
>>
>
so & needs to be skipped.
> Example:
>> Suppose n=5 and G has edges 0->2, 0->4, 3->1 and 3->4.
>> x = 00101 00000 00000 01001 00000
>> Then N(n) = 68 and
>> R(x) = R(00101 00000 00000 01001 00000) = 73 63 65 79 63.
>> So, the graph is 38 68 73 63 65 79 63.
>
>
> But when I run this line in Sage:
>
>> G1 = Graph('&D?????')
>
>
try skipping &, and also you are making directed graphs (DiGraph in Sage)
G1 = DiGraph('D?????')
this seems to work.
>
> Sage returns error:
>
>> RuntimeError: The string seems corrupt: valid characters are
>> ?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~
>
>
> How can I generate a directed graph object with `digraph6` format string,
> or some other format?
>
> e.g. directg -T : use a simple text output format (nv ne edges) instead of
> digraph6
>
>> ./geng 5 | ./directg -T
>
> 5 0
>> 5 1 0 4
>> 5 2 0 4 4 0
>> 5 2 0 4 1 4
>> 5 2 0 4 4 1
>> 5 2 4 0 4 1
>> 5 3 0 4 4 0 1 4
>> 5 3 0 4 4 0 4 1
>> 5 4 0 4 4 0 1 4 4 1
>> 5 3 0 4 1 4 2 4
>
>
> e.g. directg -G : like -T but includes group size as third item (if less
> than 10^10)
> The group size does not include exchange of isolated vertices.
>
>> ./geng 5 | ./directg -G
>> 5 0 1
>> 5 1 1 0 4
>> 5 2 2 0 4 4 0
>> 5 2 2 0 4 1 4
>> 5 2 1 0 4 4 1
>> 5 2 2 4 0 4 1
>> 5 3 1 0 4 4 0 1 4
>> 5 3 1 0 4 4 0 4 1
>> 5 4 2 0 4 4 0 1 4 4 1
>> 5 3 6 0 4 1 4 2 4
>
>
>
>
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