# nauty-shortg man page

nauty-shortg — remove isomorphs from a file of graphs

## Synopsis

**shortg** [*-qvkdu*] [*-i# -I#:# -K#*] [*-fxxx*] [*-S|-t*] [*-Tdir*] [*infile* [*outfile*]]

## Description

Remove isomorphs from a file of graphs.If outfile is omitted, it is taken to be the same as infile If both infile and outfile are omitted, input will be taken

from stdin and written to stdout

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

**-s**- force output to sparse6 format
**-g**- force output to graph6 format
**-z**- force output to digraph6 format If none of
**-s**,**-z**,**-g**are given, the output format is determined by the header or, if there is none, by the format of the first input graph. The output format determines the sorting order too. 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,loops, directed edges are not supported, nor invariants.
**-k**- output graphs have the same labelling and format as the inputs. Without
**-k**, output graphs have canonical labelling.**-s**,**-g**,**-z**are ineffective if**-k**is given. **-v**write to stderr a list of which input graphs correspond to which output graphs. The input and output graphs are both numbered beginning at 1. A line like

23 : 30 154 78

means that inputs 30, 154 and 78 were isomorphic, and produced output 23.

**-d**- include in the output only those inputs which are isomorphic to another input. If
**-k**is specified, all such inputs are included in their original labelling. Without**-k**, only one member of each nontrivial isomorphism class is written, with canonical labelling. **-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.

**-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))

**-I**#:#- select mininvarlevel and maxinvarlevel (default 1:1)
**-K**#- select invararg (default 3)
**-u**- Write no output, just report how many graphs it would have output. In this case, outfile is not permitted.
**-Tdir**- Specify that directory "dir" will be used for temporary disk
- space by the sort subprocess.
- The default is usually
*/tmp*. **-q**- Suppress auxiliary output