nauty-shortg - remove isomorphs from a file of graphs
shortg [-qvkdu] [-i# -I#:# -K#]
    [-fxxx] [-S|-t] [-Tdir] [infile
    [outfile]]
  
  - 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