127 lines
4.0 KiB
HTML
127 lines
4.0 KiB
HTML
<HTML>
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<!--
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Copyright (c) The Trustees of Indiana University
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Use, modification and distribution is subject to the Boost Software
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License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt)
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Authors: Douglas Gregor
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Andrew Lumsdaine
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-->
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<Head>
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<Title>Boost Graph Library: Small World Generator</Title>
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<script language="JavaScript" type="text/JavaScript">
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<!--
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function address(host, user) {
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}
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</script>
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</head>
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<BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b"
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ALINK="#ff0000">
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<IMG SRC="../../../boost.png"
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ALT="C++ Boost" width="277" height="86">
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<tt>small_world_iterator</tt>
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<br>
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<PRE>
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template<typename RandomGenerator, typename Graph>
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class small_world_iterator
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{
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public:
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typedef std::input_iterator_tag iterator_category;
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typedef std::pair<vertices_size_type, vertices_size_type> value_type;
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typedef const value_type& reference;
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typedef const value_type* pointer;
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typedef void difference_type;
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small_world_iterator();
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small_world_iterator(RandomGenerator& gen, vertices_size_type n,
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vertices_size_type k, double probability = 0.,
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bool allow_self_loops = false);
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// Iterator operations
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reference operator*() const;
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pointer operator->() const;
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small_world_iterator& operator++();
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small_world_iterator operator++(int);
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bool operator==(const small_world_iterator& other) const;
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bool operator!=(const small_world_iterator& other) const;
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};
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</PRE>
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<p> This class template implements a generator for small-world graphs,
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suitable for initializing an <a
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href="adjacency_list.html"><tt>adjacency_list</tt></a> or other graph
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structure with iterator-based initialization. A small-world graph
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consists of a ring graph (where each vertex is connected to its
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<em>k</em> nearest neighbors). Edges in the graph are randomly
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rewired to different vertices with a probability
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<em>p</em>. Small-world graphs exhibit a high clustering coefficient
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(because vertices are always connected to their closest neighbors),
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but rewiring ensures a small diameter.</p>
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<h3>Where Defined</h3>
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<a href="../../../boost/graph/small_world_generator.hpp"><tt>boost/graph/small_world_generator.hpp</tt></a>
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<h3>Constructors</h3>
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<a name="default-constructor"/>
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<pre>small_world_iterator();</pre>
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<blockquote>
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Constructs a past-the-end iterator.
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</blockquote>
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<pre>
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small_world_iterator(RandomGenerator& gen, vertices_size_type n,
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vertices_size_type k, double probability = 0.,
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bool allow_self_loops = false);
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</pre>
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<blockquote>
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Constructs a small-world generator iterator that creates a
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graph with <tt>n</tt> vertices, each connected to its <tt>k</tt>
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nearest neighbors. Probabilities are drawn from the
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random number generator <tt>gen</tt>. Self-loops are permitted only
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when <tt>allow_self_loops</tt> is <tt>true</tt>.
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</blockquote>
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<H3>Example</H3>
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<pre>
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#include <boost/graph/adjacency_list.hpp>
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#include <boost/graph/small_world_generator.hpp>
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#include <boost/random/linear_congruential.hpp>
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typedef boost::adjacency_list<> Graph;
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typedef boost::small_world_iterator<boost::minstd_rand, Graph> SWGen;
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int main()
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{
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boost::minstd_rand gen;
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// Create graph with 100 nodes
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Graph g(SWGen(gen, 100, 6, 0.03), SWGen(), 100);
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return 0;
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}
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</pre>
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<br>
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<HR>
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<TABLE>
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<TR valign=top>
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<TD nowrap>Copyright © 2005</TD><TD>
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<A HREF="http://www.boost.org/people/doug_gregor.html">Doug Gregor</A>, Indiana University (<script language="Javascript">address("cs.indiana.edu", "dgregor")</script>)<br>
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<A HREF="https://homes.cs.washington.edu/~al75">Andrew Lumsdaine</A>,
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Indiana University (<script language="Javascript">address("osl.iu.edu", "lums")</script>)
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</TD></TR></TABLE>
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</BODY>
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</HTML>
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