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nauty-labelg - Man Page

canonically label graphs


labelg [-q] [-sgz | -C#W#] [-fxxx] [-S|-t]


[-i# -I#:# -K#] [infile [outfile]]

Canonically label a file of graphs or digraphs.


force output to sparse6 format


force output to graph6 format


force output to digraph6 format If neither -s, -g or -z are given, the output format is determined by the header or, if there is none, by the format of the first input graph. As an exception, digraphs are always written in digraph6 format.


Use sparse representation internally.

Note that this changes the canonical labelling. Multiple edges are not supported.  One loop per vertex is ok.


Use Traces.

Note that this changes the canonical labelling. Multiple edges and loops are not supported, nor invariants.

-C# Make an invariant in 0..#-1 and output the number of graphs

with each value of the invariant.

Don't write graphs unless

-W too.

-W# (requires -C) Output the graphs with this invariant value,

in their original labelling.

Don't write the table.

The output file will have a header if and only if the input file does.


Specify a partition of the point set.  xxx is any

string of ASCII characters except nul.

This string is

considered extended to infinity on the right with the character 'z'.  One character is associated with each point, in the order given.  The labelling used obeys these rules:

(1) the new order of the points is such that the associated

characters are in ASCII ascending order

(2) if two graphs are labelled using the same string xxx,

the output graphs are identical iff there is an associated-character-preserving isomorphism between them. No option can be concatenated to the right of -f.


select an invariant (1 = twopaths, 2 = adjtriang(K), 3 = triples,

4 = quadruples, 5 = celltrips, 6 = cellquads, 7 = cellquins, 8 = distances(K), 9 = indsets(K), 10 = cliques(K), 11 = cellcliq(K),

12 = cellind(K), 13 = adjacencies, 14 = cellfano, 15 = cellfano2, 16 = refinvar(K))


select mininvarlevel and maxinvarlevel (default 1:1)


select invararg (default 3)


suppress auxiliary information


April 2024 nauty 2.8.8 Nauty Manual