NAME

       nauty-watercluster2 - (faster alternative to directg)

SYNOPSIS

       watercluster2 [ix] [oy] [S] [T] [B] [Z] [C] [m]

DESCRIPTION

              Reads graphs in g6 code or multicode (optional) from stdin and directs them

              ix: the indegree of every vertex may be at most x.

              The default maximum indegree is unlimited.

              oy: the outdegree of every vertex may be at most y.

              The default maximum outdegree is unlimited.

              S : allow that for every pair of vertices x,y at most one of the edges x-->y

              and y-->x may be present. By default both of them may be present in the same graph.

              T : Output directed graphs in T-code. This is a simple ASCII output format.

              Every line contains one graph. First the number of vertices, then the number of directed edges and
              then  the  list of directed edges with the start first and the end then. E.g.: 3 2 0 1 2 1 means 3
              vertices, 2 directed edges: 0-->1 and 2-->1

              B : Output the directed graphs in a binary code. Every item of the code is an

              unsigned char. The first unsigned char is the number nv of vertices.  The  vertices  are  numbered
              1..nv.  Then  the  list of vertices x for which there is a directed edge 1->x follow. This list is
              ended by a 0. Then the list of outgoing neighbours of 2 follows -- again ended with a 0, etc.  The
              code is complete with the 0 ending the list of outgoing neighbours of nv.

              Z : Output the directed graphs in digraph6 code. See formats.txt for a

              complete definition.

              C : Do really construct all the directed graphs in memory, but don't output

              them. This is not a big difference in case of restricted in- and outdegrees, because all  that  is
              done  extra  is that edges are directed instead of just keeping track of in- and out-degrees. This
              option is intended only for testing purposes to test also routines that are normally not used when
              counting. Things that would speed up the counting  also  in  some  cases  of  restricted  in-  and
              out-degrees  --  like  multiplying  the possibilities of assigning directions to edges that can be
              assigned directions independent of each other (depending on the degrees  of  the  endvertices  and
              overlaps) -- are not included.  In case of not restrictive bounds on the in- and out-degree it not
              really  constructing  the  graphs  can  be  considerably  faster.  In  cases of restricted in- and
              out-degrees the only difference is that the graph isn't modified.  The fact that  in  case  of  no
              output  the  graph is not modified is mainly to save time for the one case of waterclusters, where
              large numbers were determined. If  large  numbers  (without  output)  for  other  cases  shall  be
              determined, one should think about adding the multiplication routines.

              m : read multicode instead of g6 code

       This program uses different labelling routines -- all based on the ideas of

       G.  Brinkmann, Generating water clusters and other directed graphs,mJournal of Mathematical Chemistry 46,
       1112--1121 (2009)

nauty 2.8.9                                      September 2024                           NAUTY-WATERCLUSTER2(1)