Boost C++ Libraries

libs/graph/example/fr_layout.cpp

// Copyright 2004 The Trustees of Indiana University.

// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)

//  Authors: Douglas Gregor
//           Andrew Lumsdaine
#include <boost/graph/fruchterman_reingold.hpp>
#include <boost/graph/random_layout.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/topology.hpp>
#include <boost/lexical_cast.hpp>
#include <string>
#include <iostream>
#include <map>
#include <vector>
#include <boost/random/linear_congruential.hpp>
#include <boost/progress.hpp>
#include <boost/shared_ptr.hpp>

using namespace boost;

void usage()
{
    std::cerr << "Usage: fr_layout [options] <width> <height>\n"
              << "Arguments:\n"
              << "\t<width>\tWidth of the display area (floating point)\n"
              << "\t<Height>\tHeight of the display area (floating point)\n\n"
              << "Options:\n"
              << "\t--iterations n\tNumber of iterations to execute.\n"
              << "\t\t\tThe default value is 100.\n"
              << "Input:\n"
              << "  Input is read from standard input as a list of edges, one "
                 "per line.\n"
              << "  Each edge contains two string labels (the endpoints) "
                 "separated by a space.\n\n"
              << "Output:\n"
              << "  Vertices and their positions are written to standard "
                 "output with the label,\n  x-position, and y-position of a "
                 "vertex on each line, separated by spaces.\n";
}

typedef boost::rectangle_topology<> topology_type;
typedef topology_type::point_type point_type;

typedef adjacency_list< listS, vecS, undirectedS,
    property< vertex_name_t, std::string > >
    Graph;

typedef graph_traits< Graph >::vertex_descriptor Vertex;

typedef std::map< std::string, Vertex > NameToVertex;

Vertex get_vertex(const std::string& name, Graph& g, NameToVertex& names)
{
    NameToVertex::iterator i = names.find(name);
    if (i == names.end())
        i = names.insert(std::make_pair(name, add_vertex(name, g))).first;
    return i->second;
}

class progress_cooling : public linear_cooling< double >
{
    typedef linear_cooling< double > inherited;

public:
    explicit progress_cooling(std::size_t iterations) : inherited(iterations)
    {
        display.reset(new progress_display(iterations + 1, std::cerr));
    }

    double operator()()
    {
        ++(*display);
        return inherited::operator()();
    }

private:
    shared_ptr< boost::progress_display > display;
};

int main(int argc, char* argv[])
{
    int iterations = 100;

    if (argc < 3)
    {
        usage();
        return -1;
    }

    double width = 0;
    double height = 0;

    for (int arg_idx = 1; arg_idx < argc; ++arg_idx)
    {
        std::string arg = argv[arg_idx];
        if (arg == "--iterations")
        {
            ++arg_idx;
            if (arg_idx >= argc)
            {
                usage();
                return -1;
            }
            iterations = lexical_cast< int >(argv[arg_idx]);
        }
        else
        {
            if (width == 0.0)
                width = lexical_cast< double >(arg);
            else if (height == 0.0)
                height = lexical_cast< double >(arg);
            else
            {
                usage();
                return -1;
            }
        }
    }

    if (width == 0.0 || height == 0.0)
    {
        usage();
        return -1;
    }

    Graph g;
    NameToVertex names;

    std::string source, target;
    while (std::cin >> source >> target)
    {
        add_edge(get_vertex(source, g, names), get_vertex(target, g, names), g);
    }

    typedef std::vector< point_type > PositionVec;
    PositionVec position_vec(num_vertices(g));
    typedef iterator_property_map< PositionVec::iterator,
        property_map< Graph, vertex_index_t >::type >
        PositionMap;
    PositionMap position(position_vec.begin(), get(vertex_index, g));

    minstd_rand gen;
    topology_type topo(gen, -width / 2, -height / 2, width / 2, height / 2);
    random_graph_layout(g, position, topo);
    fruchterman_reingold_force_directed_layout(
        g, position, topo, cooling(progress_cooling(iterations)));

    graph_traits< Graph >::vertex_iterator vi, vi_end;
    for (boost::tie(vi, vi_end) = vertices(g); vi != vi_end; ++vi)
    {
        std::cout << get(vertex_name, g, *vi) << '\t' << position[*vi][0]
                  << '\t' << position[*vi][1] << std::endl;
    }
    return 0;
}