NAUTY Format

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Detailed Description

Tool to read graphs from Nauty format data.

Files
file	nauty_reader.h
	Nauty file reader.
Functions
template<typename Graph >
std::istream &	readNautyGraph (Graph &graph, std::istream &is=std::cin)
	Nauty file reader.

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Function Documentation

std::istream& lemon::readNautyGraph	(	Graph &	graph,
		std::istream &	is = std::cin
	)

The geng program is in the gtools suite of the nauty package. This tool can generate all non-isomorphic undirected graphs of several classes with given node number (e.g. general, connected, biconnected, triangle-free, 4-cycle-free, bipartite and graphs with given edge number and degree constraints). This function reads a nauty graph6 format line from the given stream and builds it in the given graph.

The site of nauty package: http://cs.anu.edu.au/~bdm/nauty/

For example, the number of all non-isomorphic planar graphs can be computed with the following code.

      int num = 0;
      SmartGraph graph;
      while (readNautyGraph(graph, std::cin)) {
        PlanarityChecking<SmartGraph> pc(graph);
        if (pc.run()) ++num;
      }
      std::cout << "Number of planar graphs: " << num << std::endl;

The nauty files are quite huge, therefore instead of the direct file generation pipelining is recommended. For example,

      ./geng -c 10 | ./num_of_planar_graphs