1 | //======================================================================= |
2 | // Copyright 1997, 1998, 1999, 2000 University of Notre Dame. |
3 | // Copyright (C) Vladimir Prus 2003 |
4 | // Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek |
5 | // |
6 | // Distributed under the Boost Software License, Version 1.0. (See |
7 | // accompanying file LICENSE_1_0.txt or copy at |
8 | // http://www.boost.org/LICENSE_1_0.txt) |
9 | //======================================================================= |
10 | #ifndef BOOST_GRAPH_RANDOM_HPP |
11 | #define BOOST_GRAPH_RANDOM_HPP |
12 | |
13 | #include <boost/graph/graph_traits.hpp> |
14 | #include <boost/random/uniform_int.hpp> |
15 | #include <boost/random/uniform_real.hpp> |
16 | #include <boost/random/variate_generator.hpp> |
17 | |
18 | #include <boost/pending/property.hpp> |
19 | #include <boost/graph/properties.hpp> |
20 | #include <boost/graph/iteration_macros.hpp> |
21 | #include <boost/next_prior.hpp> |
22 | |
23 | #include <boost/graph/adjacency_list.hpp> |
24 | #include <boost/graph/copy.hpp> |
25 | #include <boost/mpl/if.hpp> |
26 | #include <boost/type_traits/is_convertible.hpp> |
27 | |
28 | #include <iostream> |
29 | #include <boost/assert.hpp> |
30 | |
31 | namespace boost { |
32 | |
33 | // grab a random vertex from the graph's vertex set |
34 | template <class Graph, class RandomNumGen> |
35 | typename graph_traits<Graph>::vertex_descriptor |
36 | random_vertex(Graph& g, RandomNumGen& gen) |
37 | { |
38 | if (num_vertices(g) > 1) { |
39 | #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581)) |
40 | std::size_t n = std::random( num_vertices(g) ); |
41 | #else |
42 | uniform_int<> distrib(0, num_vertices(g)-1); |
43 | variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib); |
44 | std::size_t n = rand_gen(); |
45 | #endif |
46 | typename graph_traits<Graph>::vertex_iterator |
47 | i = vertices(g).first; |
48 | return *(boost::next(i, n)); |
49 | } else |
50 | return *vertices(g).first; |
51 | } |
52 | |
53 | template <class Graph, class RandomNumGen> |
54 | typename graph_traits<Graph>::edge_descriptor |
55 | random_edge(Graph& g, RandomNumGen& gen) { |
56 | if (num_edges(g) > 1) { |
57 | #if BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT(0x581)) |
58 | typename graph_traits<Graph>::edges_size_type |
59 | n = std::random( num_edges(g) ); |
60 | #else |
61 | uniform_int<> distrib(0, num_edges(g)-1); |
62 | variate_generator<RandomNumGen&, uniform_int<> > rand_gen(gen, distrib); |
63 | typename graph_traits<Graph>::edges_size_type |
64 | n = rand_gen(); |
65 | #endif |
66 | typename graph_traits<Graph>::edge_iterator |
67 | i = edges(g).first; |
68 | return *(boost::next(i, n)); |
69 | } else |
70 | return *edges(g).first; |
71 | } |
72 | |
73 | template <typename Graph, typename RandomNumGen> |
74 | typename graph_traits<Graph>::edge_descriptor |
75 | random_out_edge(Graph& g, typename graph_traits<Graph>::vertex_descriptor src, RandomNumGen& gen) { |
76 | typedef typename graph_traits<Graph>::degree_size_type degree_size_type; |
77 | typedef boost::uniform_int<degree_size_type> ui_type; |
78 | ui_type ui(0, out_degree(src, g) - 1); |
79 | boost::variate_generator<RandomNumGen&, ui_type> |
80 | variate(gen, ui); |
81 | typename graph_traits<Graph>::out_edge_iterator it = out_edges(src, g).first; |
82 | std::advance(it, variate()); |
83 | return *it; |
84 | } |
85 | |
86 | template <typename Graph, typename WeightMap, typename RandomNumGen> |
87 | typename graph_traits<Graph>::edge_descriptor |
88 | weighted_random_out_edge(Graph& g, typename graph_traits<Graph>::vertex_descriptor src, WeightMap weight, RandomNumGen& gen) { |
89 | typedef typename property_traits<WeightMap>::value_type weight_type; |
90 | weight_type weight_sum(0); |
91 | BGL_FORALL_OUTEDGES_T(src, e, g, Graph) {weight_sum += get(weight, e);} |
92 | typedef boost::uniform_real<> ur_type; |
93 | ur_type ur(0, weight_sum); |
94 | boost::variate_generator<RandomNumGen&, ur_type> |
95 | variate(gen, ur); |
96 | weight_type chosen_weight = variate(); |
97 | BGL_FORALL_OUTEDGES_T(src, e, g, Graph) { |
98 | weight_type w = get(weight, e); |
99 | if (chosen_weight < w) { |
100 | return e; |
101 | } else { |
102 | chosen_weight -= w; |
103 | } |
104 | } |
105 | BOOST_ASSERT (false); // Should not get here |
106 | } |
107 | |
108 | namespace detail { |
109 | class dummy_property_copier { |
110 | public: |
111 | template<class V1, class V2> |
112 | void operator()(const V1&, const V2&) const {} |
113 | }; |
114 | } |
115 | |
116 | template <typename MutableGraph, class RandNumGen> |
117 | void generate_random_graph1 |
118 | (MutableGraph& g, |
119 | typename graph_traits<MutableGraph>::vertices_size_type V, |
120 | typename graph_traits<MutableGraph>::vertices_size_type E, |
121 | RandNumGen& gen, |
122 | bool allow_parallel = true, |
123 | bool self_edges = false) |
124 | { |
125 | typedef graph_traits<MutableGraph> Traits; |
126 | typedef typename Traits::edge_descriptor edge_t; |
127 | typedef typename Traits::vertices_size_type v_size_t; |
128 | typedef typename Traits::edges_size_type e_size_t; |
129 | typedef typename Traits::vertex_descriptor vertex_descriptor; |
130 | |
131 | // When parallel edges are not allowed, we create a new graph which |
132 | // does not allow parallel edges, construct it and copy back. |
133 | // This is not efficient if 'g' already disallow parallel edges, |
134 | // but that's task for later. |
135 | if (!allow_parallel) { |
136 | |
137 | typedef typename boost::graph_traits<MutableGraph>::directed_category dir; |
138 | typedef typename mpl::if_<is_convertible<dir, directed_tag>, |
139 | directedS, undirectedS>::type select; |
140 | adjacency_list<setS, vecS, select> g2; |
141 | generate_random_graph1(g2, V, E, gen, true, self_edges); |
142 | |
143 | copy_graph(g2, g, vertex_copy(p: detail::dummy_property_copier()). |
144 | edge_copy(p: detail::dummy_property_copier())); |
145 | |
146 | } else { |
147 | |
148 | for (v_size_t i = 0; i < V; ++i) |
149 | add_vertex(g); |
150 | |
151 | e_size_t not_inserted_counter = 0; /* Number of edge insertion failures */ |
152 | e_size_t num_vertices_squared = num_vertices(g) * num_vertices(g); |
153 | for (e_size_t j = 0; j < E; /* Increment in body */) { |
154 | vertex_descriptor a = random_vertex(g, gen), b; |
155 | do { |
156 | b = random_vertex(g, gen); |
157 | } while (self_edges == false && a == b); |
158 | edge_t e; bool inserted; |
159 | boost::tie(e, inserted) = add_edge(a, b, g); |
160 | if (inserted) { |
161 | ++j; |
162 | } else { |
163 | ++not_inserted_counter; |
164 | } |
165 | if (not_inserted_counter >= num_vertices_squared) { |
166 | return; /* Rather than looping forever on complete graph */ |
167 | } |
168 | } |
169 | } |
170 | } |
171 | |
172 | template <typename MutableGraph, class RandNumGen> |
173 | void generate_random_graph |
174 | (MutableGraph& g, |
175 | typename graph_traits<MutableGraph>::vertices_size_type V, |
176 | typename graph_traits<MutableGraph>::vertices_size_type E, |
177 | RandNumGen& gen, |
178 | bool allow_parallel = true, |
179 | bool self_edges = false) |
180 | { |
181 | generate_random_graph1(g, V, E, gen, allow_parallel, self_edges); |
182 | } |
183 | |
184 | template <typename MutableGraph, typename RandNumGen, |
185 | typename VertexOutputIterator, typename EdgeOutputIterator> |
186 | void generate_random_graph |
187 | (MutableGraph& g, |
188 | typename graph_traits<MutableGraph>::vertices_size_type V, |
189 | typename graph_traits<MutableGraph>::vertices_size_type E, |
190 | RandNumGen& gen, |
191 | VertexOutputIterator vertex_out, |
192 | EdgeOutputIterator edge_out, |
193 | bool self_edges = false) |
194 | { |
195 | typedef graph_traits<MutableGraph> Traits; |
196 | typedef typename Traits::vertices_size_type v_size_t; |
197 | typedef typename Traits::edges_size_type e_size_t; |
198 | typedef typename Traits::vertex_descriptor vertex_t; |
199 | typedef typename Traits::edge_descriptor edge_t; |
200 | |
201 | for (v_size_t i = 0; i < V; ++i) |
202 | *vertex_out++ = add_vertex(g); |
203 | |
204 | e_size_t not_inserted_counter = 0; /* Number of edge insertion failures */ |
205 | e_size_t num_vertices_squared = num_vertices(g) * num_vertices(g); |
206 | for (e_size_t j = 0; j < E; /* Increment in body */) { |
207 | vertex_t a = random_vertex(g, gen), b; |
208 | do { |
209 | b = random_vertex(g, gen); |
210 | } while (self_edges == false && a == b); |
211 | edge_t e; bool inserted; |
212 | boost::tie(e, inserted) = add_edge(a, b, g); |
213 | if (inserted) { |
214 | *edge_out++ = std::make_pair(source(e, g), target(e, g)); |
215 | ++j; |
216 | } else { |
217 | ++not_inserted_counter; |
218 | } |
219 | if (not_inserted_counter >= num_vertices_squared) { |
220 | return; /* Rather than looping forever on complete graph */ |
221 | } |
222 | } |
223 | } |
224 | |
225 | namespace detail { |
226 | |
227 | template<class Property, class G, class RandomGenerator> |
228 | void randomize_property(G& g, RandomGenerator& rg, |
229 | Property, vertex_property_tag) |
230 | { |
231 | typename property_map<G, Property>::type pm = get(Property(), g); |
232 | typename graph_traits<G>::vertex_iterator vi, ve; |
233 | for (boost::tie(vi, ve) = vertices(g); vi != ve; ++vi) { |
234 | pm[*vi] = rg(); |
235 | } |
236 | } |
237 | |
238 | template<class Property, class G, class RandomGenerator> |
239 | void randomize_property(G& g, RandomGenerator& rg, |
240 | Property, edge_property_tag) |
241 | { |
242 | typename property_map<G, Property>::type pm = get(Property(), g); |
243 | typename graph_traits<G>::edge_iterator ei, ee; |
244 | for (boost::tie(ei, ee) = edges(g); ei != ee; ++ei) { |
245 | pm[*ei] = rg(); |
246 | } |
247 | } |
248 | } |
249 | |
250 | template<class Property, class G, class RandomGenerator> |
251 | void randomize_property(G& g, RandomGenerator& rg) |
252 | { |
253 | detail::randomize_property |
254 | (g, rg, Property(), typename property_kind<Property>::type()); |
255 | } |
256 | |
257 | |
258 | |
259 | |
260 | } |
261 | |
262 | #include <boost/graph/iteration_macros_undef.hpp> |
263 | |
264 | #endif |
265 | |