ScaleFree.cc

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#include <iostream>
#include <sstream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/plod_generator.hpp>
#include <boost/random/linear_congruential.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <boost/date_time/gregorian/gregorian.hpp>
typedef boost::adjacency_list<> Graph;
typedef boost::plod_iterator<boost::minstd_rand, Graph> SFGen;

void printUsage()
{
  std::cout << "Usage: scale_free nbNodes alpha beta random_generator_seed" << std::endl;
  std::cout << "Produces a scale-free network (See Boost Graph Library) in 'topo' format on the standard output" << std::endl;
  std::cout << "based the Power Law Out Degree algorithm. The number of connectivity 'credits' assigned to a node is defined by beta*random_number(0,nbNodes-1)^(-alpha)." << std::endl;
  exit(1);
}
using namespace boost::posix_time;
int main(int argc, char ** argv)
{
    boost::gregorian::date d(boost::gregorian::day_clock::local_day());
    std::cout << d.month().as_long_string() << std::endl;
    second_clock::local_time();
    time_duration duration;
  if(argc != 5)
        {
          printUsage();
        }
  std::stringstream stream;
  stream << argv[1];
  Graph::vertices_size_type nbNodes = 0;
  stream >> nbNodes;
  stream.clear();

  double  alpha = 0;
  stream << argv[2];
  stream >> alpha;
  stream.clear();

  double beta = 0.0;
  stream << argv[3];
  stream >> beta;
  stream.clear();


  int seed = 0;
  stream << argv[4];
  stream >> seed;
  stream.clear();
  
  boost::minstd_rand gen;
  gen.seed(seed);

  Graph g(SFGen(gen, nbNodes, alpha, beta,true), SFGen(), nbNodes);
  typedef boost::property_map<Graph, boost::vertex_index_t>::type IndexMap;
  IndexMap index = get(boost::vertex_index, g);
  std::pair<Graph::edge_iterator,Graph::edge_iterator> pair = edges(g);
  std::cout << "p top " << num_vertices(g) << " " << num_edges(g) << std::endl;
  unsigned i = 0;
  for(Graph::edge_iterator it = pair.first; it != pair.second; ++it)
        {
          std::cout << "c" << i << ": n" << index[source(*it,g)] << ", n" << index[target(*it,g)] << ";" << std::endl;
          ++i;
        }
  return 0;
}