The header `<boost/graph/random>` provides routines to create random graph, select random vertices and edges, and randomize properties.

# Synopsis

      template <class Graph, class RandomNumGen>
      typename graph_traits<Graph>::vertex_descriptor
      random_vertex(Graph& g, RandomNumGen& gen);

      template <class Graph, class RandomNumGen>
      typename graph_traits<Graph>::edge_descriptor
      random_edge(Graph& g, RandomNumGen& gen);

      template <typename MutableGraph, class RandNumGen>
      void generate_random_graph
        (MutableGraph& g,
         typename graph_traits<MutableGraph>::vertices_size_type V,
         typename graph_traits<MutableGraph>::vertices_size_type E,
         RandNumGen& gen,
         bool self_edges = false);

      template<class Property, class G, class RandomGenerator>
        void randomize_property(G& g, RandomGenerator rg);

# Description

## random_vertex

      template <class Graph, class RandomNumGen>
      typename graph_traits<Graph>::vertex_descriptor
      random_vertex(Graph& g, RandomNumGen& gen);

Effects: Selects a random vertex in a graph and returns it.

Preconditions: `num_vertices(g) != 0`

Complexity: `O(num_vertices(g))`

## random_edge

      template <class Graph, class RandomNumGen>
      typename graph_traits<Graph>::edge_descriptor
      random_edge(Graph& g, RandomNumGen& gen);

Effects: Selects a random edge in a graph and returns it.

Preconditions: `num_edges(g) != 0`

Complexity: `O(num_edges(g))`

## generate_random_graph

      template <typename MutableGraph, class RandNumGen>
      void generate_random_graph
        (MutableGraph& g,
         typename graph_traits<MutableGraph>::vertices_size_type V,
         typename graph_traits<MutableGraph>::vertices_size_type E,
         RandNumGen& gen,
         bool allow_parallel = true,
         bool self_edges = false);

Effects: Adds `V` vertices and `E` edges, to `g`. Source and target vertices of each edge are randomly choosen. If `self_edges` is false, then no edge will have the same source and targets.

Precondition: `num_vertices(g) == 0`

Compleixity: `O(V*E)`

## randomize_property

      template<class Property, class G, class RandomGenerator>
        void randomize_property(G& g, RandomGenerator& rg);

Effects: Sets the random value of property on either all vertices, or all edges, depending on property kind.

Complexity: `O(V)` or `O(E)`, depending on property kind.

Last modified: Feb 05, 2003

© Copyright Vladimir Prus 2003. Permission to copy, use, modify, sell and distribute this document is granted provided this copyright notice appears in all copies. This document is provided ``as is'' without express or implied warranty, and with no claim as to its suitability for any purpose.