ceph/src/boost/libs/graph_parallel/test/distributed_page_rank_test.cpp

   1 // Copyright 2004 The Trustees of Indiana University.
   2
   3 // Use, modification and distribution is subject to the Boost Software
   4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 //  Authors: Douglas Gregor
   8 //           Andrew Lumsdaine
   9
  10 #include <boost/graph/use_mpi.hpp>
  11 #include <boost/throw_exception.hpp>
  12 #include <boost/serialization/vector.hpp>
  13 #include <boost/graph/distributed/page_rank.hpp>
  14 #include <boost/core/lightweight_test.hpp>
  15 #include <boost/graph/distributed/adjacency_list.hpp>
  16 #include <boost/graph/distributed/mpi_process_group.hpp>
  17 #include <boost/core/lightweight_test.hpp>
  18 #include <vector>
  19 #include <iostream>
  20 #include <stdlib.h>
  21
  22 #ifdef BOOST_NO_EXCEPTIONS
  23 void
  24 boost::throw_exception(std::exception const& ex)
  25 {
  26     std::cout << ex.what() << std::endl;
  27     abort();
  28 }
  29 #endif
  30
  31 using namespace boost;
  32 using boost::graph::distributed::mpi_process_group;
  33
  34 bool close_to(double x, double y)
  35 {
  36   double diff = x - y;
  37   if (diff < 0) diff = -diff;
  38   double base = (y == 0? x : y);
  39   if (base != 0) return diff / base < 0.01;
  40   else return true;
  41 }
  42
  43 // Make convenient labels for the vertices
  44 enum vertex_id_t { A, B, C, D, N };
  45
  46 void test_distributed_page_rank(int iterations)
  47 {
  48   using namespace boost::graph;
  49
  50   // create a typedef for the Graph type
  51   typedef adjacency_list<vecS,
  52                          distributedS<mpi_process_group, vecS>,
  53                          bidirectionalS
  54                          > Graph;
  55   typedef graph_traits<Graph>::vertex_descriptor vertex_descriptor;
  56
  57   // writing out the edges in the graph
  58   typedef std::pair<int, int> Edge;
  59   Edge edge_array[] =
  60     { Edge(A,B), Edge(A,C), Edge(B,C), Edge(C,A), Edge(D,C) };
  61   const int num_edges = sizeof(edge_array)/sizeof(edge_array[0]);
  62
  63   // declare a graph object
  64   Graph g(edge_array, edge_array + num_edges, N);
  65
  66   std::vector<double> ranks(num_vertices(g));
  67
  68   page_rank(g,
  69             make_iterator_property_map(ranks.begin(),
  70                                        get(boost::vertex_index, g)),
  71             n_iterations(iterations), 0.85, N);
  72
  73   double local_sum = 0.0;
  74   for(unsigned int i = 0; i < num_vertices(g); ++i) {
  75     std::cout << (char)('A' + g.distribution().global(i)) << " = "
  76               << ranks[i] << std::endl;
  77     local_sum += ranks[i];
  78   }
  79   double sum=0.;
  80   boost::mpi::reduce(communicator(g.process_group()),
  81                      local_sum, sum, std::plus<double>(), 0);
  82   if (process_id(g.process_group()) == 0) {
  83     std::cout << "Sum = " << sum << "\n\n";
  84     BOOST_TEST(close_to(sum, 4)); // 1 when alpha=0
  85   }
  86
  87   //   double expected_ranks0[N] = {0.400009, 0.199993, 0.399998, 0.0};
  88   double expected_ranks[N] = {1.49011, 0.783296, 1.5766, 0.15};
  89   for (int i = 0; i < N; ++i) {
  90     vertex_descriptor v = vertex(i, g);
  91     if (v != Graph::null_vertex()
  92         && owner(v) == process_id(g.process_group())) {
  93       BOOST_TEST(close_to(ranks[local(v)], expected_ranks[i]));
  94     }
  95   }
  96 }
  97
  98 int main(int argc, char* argv[])
  99 {
 100   mpi::environment env(argc, argv);
 101
 102   int iterations = 50;
 103   if (argc > 1) {
 104     iterations = atoi(argv[1]);
 105   }
 106
 107   test_distributed_page_rank(iterations);
 108
 109   return boost::report_errors();
 110 }