## table of contents

NAUTY-LABELG(1) | Nauty Manual | NAUTY-LABELG(1) |

# NAME¶

nauty-labelg - canonically label graphs

# SYNOPSIS¶

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

# DESCRIPTION¶

- [-i#
**-I**#:#**-K**#] [infile [outfile]] - Canonically label a file of graphs or digraphs.

**-s**- force output to sparse6 format
**-g**- force output to graph6 format
**-z**- 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. **-S**- Use sparse representation internally.

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

**-t**- 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.

**-fxxx**- 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**.

**-i**#- 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))

July 2022 | nauty 2.7.4 |