Pgr_randomSpanningTree< G > Class Template Reference

#include "pgr_randomSpanningTree.hpp"

Collaboration diagram for Pgr_randomSpanningTree< G >:

Public Types
typedef G::E	E
typedef G::V	V

Public Member Functions
std::vector< pgr_randomSpanningTree_t >	randomSpanningTree (G &graph, int64_t root_vertex)

Private Member Functions
std::vector< pgr_randomSpanningTree_t >	undirectedGraph (const G &graph, int64_t root_vertex)

Private Attributes
std::vector< V >	predecessors

Detailed Description

template<class G>
class Pgr_randomSpanningTree< G >

Definition at line 47 of file pgr_randomSpanningTree.hpp.

Member Typedef Documentation

E

template<class G >

typedef G::E Pgr_randomSpanningTree< G >::E

Definition at line 57 of file pgr_randomSpanningTree.hpp.

V

template<class G >

typedef G::V Pgr_randomSpanningTree< G >::V

Definition at line 56 of file pgr_randomSpanningTree.hpp.

Member Function Documentation

randomSpanningTree()

template<class G >

std::vector< pgr_randomSpanningTree_t > Pgr_randomSpanningTree< G >::randomSpanningTree	(	G &	graph,
		int64_t	root_vertex
	)

Definition at line 137 of file pgr_randomSpanningTree.hpp.

                                      {
      predecessors.clear();
      // TODO(aps)
      // Currently only running for undirected graph
      return undirectedGraph(
              graph,
              root_vertex);
}

Referenced by pgr_randomSpanningTree().

undirectedGraph()

template<class G >

std::vector< pgr_randomSpanningTree_t > Pgr_randomSpanningTree< G >::undirectedGraph ( const G &  graph, int64_t  root_vertex  )

inlineprivate

Definition at line 69 of file pgr_randomSpanningTree.hpp.

                                    {
         std::ostringstream log;
         auto v_root(graph.get_V(root_vertex));
 
         std::minstd_rand rng;
 
          /* abort in case of an interruption occurs (e.g. the query is being cancelled) */
          CHECK_FOR_INTERRUPTS();
 
         // TODO(aps)
         // This function is running in infinite loop
         try {
             boost::random_spanning_tree(
                     graph.graph,
                     rng,
                     boost::root_vertex(v_root)
                     .predecessor_map(&predecessors[0])
                     .weight_map(get(&G::G_T_E::cost, graph.graph)));
         } catch (std::exception const &ex) {
             log << ex.what();
         } catch (...) {
             log << "Unknown exception caught";
         }
 
         std::vector< pgr_randomSpanningTree_t > resul;
         return resul;
         std::vector< pgr_randomSpanningTree_t > results;
         double totalcost = 0;
         pgr_randomSpanningTree_t tmp;
 
         tmp.root_vertex = root_vertex;
         tmp.edge = -1;
         tmp.cost = 0;
         tmp.tree_cost = totalcost;
 
         results.push_back(tmp);
 
         for (size_t j = 0; j < predecessors.size(); j++) {
           if (j != v_root) {
             pgr_randomSpanningTree_t tmp;
 
             auto start_node = graph.graph[predecessors[j]].id;
             auto end_node = graph.graph[j].id;  // node
 
             auto v_sn(graph.get_V(start_node));
             auto v_en(graph.get_V(end_node));
 
             auto cost = graph[boost::edge(
                     predecessors[j], j, graph.graph).first].cost;
             auto edge_id =
                 graph.get_edge_id(v_sn, v_en, cost);
         totalcost += cost;
 
             tmp.root_vertex = root_vertex;
             tmp.edge = edge_id;         // edge_id
             tmp.cost = cost;            // cost
             tmp.tree_cost = totalcost;      // tree_cost
             results.push_back(tmp);
           }
         }
         return results;
    }

References pgr_randomSpanningTree_t::cost, pgr_randomSpanningTree_t::edge, Pgr_randomSpanningTree< G >::predecessors, pgr_randomSpanningTree_t::root_vertex, and pgr_randomSpanningTree_t::tree_cost.

Member Data Documentation

predecessors

template<class G >

std::vector< V > Pgr_randomSpanningTree< G >::predecessors

private

Definition at line 65 of file pgr_randomSpanningTree.hpp.

Referenced by Pgr_randomSpanningTree< G >::undirectedGraph().

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The documentation for this class was generated from the following file:

• pgr_randomSpanningTree.hpp