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| 2 | <!-- |
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| 3 | -- Copyright (c) Jeremy Siek 2000 |
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| 4 | -- |
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| 5 | -- Distributed under the Boost Software License, Version 1.0. |
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| 6 | -- (See accompanying file LICENSE_1_0.txt or copy at |
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| 7 | -- http://www.boost.org/LICENSE_1_0.txt) |
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| 8 | --> |
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| 9 | <Head> |
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| 10 | <Title>Boost Graph Library: Transpose Graph</Title> |
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| 11 | <BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b" |
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| 12 | ALINK="#ff0000"> |
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| 13 | <IMG SRC="../../../boost.png" |
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| 14 | ALT="C++ Boost" width="277" height="86"> |
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| 15 | |
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| 16 | <BR Clear> |
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| 17 | |
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| 18 | <H1><TT>transpose_graph</TT></H1> |
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| 19 | |
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| 20 | <PRE> |
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| 21 | template <class <a href="./VertexListGraph.html">VertexListGraph</a>, class <a href="./MutableGraph.html">MutableGraph</a>> |
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| 22 | void transpose_graph(const VertexListGraph& G, MutableGraph& G_T, |
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| 23 | const bgl_named_params<P, T, R>& params = <i>all defaults</i>) |
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| 24 | </PRE> |
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| 25 | |
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| 26 | <P> |
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| 27 | This function computes the transpose of a directed graph. The |
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| 28 | transpose of a directed graph <i>G = (V, E)</i>is the graph |
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| 29 | <i>G<sup>T</sup> = (V, E<sup>T</sup>)</i> , where <i>E<sup>T</sup> = |
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| 30 | {(v, u) in V x V: (u, v) in E}</i> . i.e., <i>G<sup>T</sup></i> is |
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| 31 | <i>G</i> with all its edges reversed. Graph <TT>G_T</TT> passed into |
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| 32 | the algorithm must have no vertices and |
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| 33 | no edges. The vertices and edges will be added by <tt>transpose_graph()</tt> by |
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| 34 | calling <tt>add_vertex</tt> and <tt>add_edge</tt> as follows for each edge |
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| 35 | <i>(u,v)</i> in <tt>G</tt>. |
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| 36 | |
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| 37 | <H3>Example</H3> |
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| 38 | |
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| 39 | Here's an example of transposing a graph: |
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| 40 | <a href="../example/transpose-example.cpp"><tt>example/transpose-example.cpp</tt></a>. |
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| 41 | |
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| 42 | <H3>Where Defined</H3> |
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| 43 | |
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| 44 | <P> |
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| 45 | <a href="../../../boost/graph/transpose_graph.hpp"><TT>boost/graph/transpose_graph.hpp</TT></a> |
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| 46 | |
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| 47 | <P> |
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| 48 | |
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| 49 | <H3>Parameters</H3> |
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| 50 | |
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| 51 | IN: <tt>const VertexListGraph& G</tt> |
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| 52 | <blockquote> |
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| 53 | A directed graph. The graph type must be a model of <a href="./VertexListGraph.html">Vertex List Graph</a>. |
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| 54 | </blockquote> |
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| 55 | |
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| 56 | OUT: <tt>const MutableGraph& G_T</tt> |
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| 57 | <blockquote> |
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| 58 | The transposed graph. The graph type must be a model of <a |
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| 59 | href="./MutableGraph.html">Mutable Graph</a>. |
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| 60 | </blockquote> |
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| 61 | |
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| 62 | <h3>Named Parameters</h3> |
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| 63 | |
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| 64 | IN: <tt>vertex_copy(VertexCopier vc)</tt> |
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| 65 | <blockquote> |
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| 66 | This is a <a href="http://www.sgi.com/tech/stl/BinaryFunction.html">Binary Function</a> that copies the properties of a vertex in the original graph |
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| 67 | into the corresponding vertex in the copy.<br> |
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| 68 | |
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| 69 | <b>Default:</b> <tt>vertex_copier<VertexListGraph, MutableGraph></tt> |
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| 70 | which uses the property tag <tt>vertex_all</tt> to access a property |
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| 71 | map from the graph. |
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| 72 | </blockquote> |
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| 73 | |
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| 74 | IN: <tt>edge_copy(EdgeCopier ec)</tt> |
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| 75 | <blockquote> |
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| 76 | This is a <a href="http://www.sgi.com/tech/stl/BinaryFunction.html">Binary Function</a> that copies the properties of an edge in the original graph |
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| 77 | into the corresponding edge in the copy.<br> |
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| 78 | |
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| 79 | <b>Default:</b> <tt>edge_copier<VertexListGraph, MutableGraph></tt> |
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| 80 | which uses the property tag <tt>edge_all</tt> to access a property |
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| 81 | map from the graph. |
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| 82 | </blockquote> |
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| 83 | |
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| 84 | IN: <tt>vertex_index_map(VertexIndexMap i_map)</tt> |
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| 85 | <blockquote> |
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| 86 | The vertex index map type must be a model of <a |
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| 87 | href="../../property_map/ReadablePropertyMap.html">Readable Property |
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| 88 | Map</a> and must map the vertex descriptors of <tt>G</tt> to the |
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| 89 | integers from 0 to <tt>num_vertices(G)</tt>.<br> |
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| 90 | |
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| 91 | <b>Default:</b> <tt>get(vertex_index, G)</tt> |
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| 92 | Note: if you use this default, make sure your graph has |
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| 93 | an internal <tt>vertex_index</tt> property. For example, |
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| 94 | <tt>adjacenty_list</tt> with <tt>VertexList=listS</tt> does |
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| 95 | not have an internal <tt>vertex_index</tt> property. |
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| 96 | </blockquote> |
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| 97 | |
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| 98 | |
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| 99 | UTIL/OUT: <tt>orig_to_copy(Orig2CopyMap c)</tt> |
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| 100 | <blockquote> |
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| 101 | This maps vertices in the original graph to vertices in the copy. |
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| 102 | |
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| 103 | <b>Default:</b> an <a |
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| 104 | href="../../property_map/iterator_property_map.html"> |
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| 105 | </tt>iterator_property_map</tt></a> created from a |
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| 106 | <tt>std::vector</tt> of the output graph's vertex descriptor type of size |
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| 107 | <tt>num_vertices(g)</tt> and using the <tt>i_map</tt> for the index |
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| 108 | map. |
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| 109 | </blockquote> |
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| 110 | |
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| 111 | <H3>Complexity</H3> |
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| 112 | |
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| 113 | <P> |
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| 114 | The time complexity is <i>O(V + E)</i>. |
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| 115 | |
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| 116 | |
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| 117 | |
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| 118 | <br> |
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| 119 | <HR> |
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| 120 | <TABLE> |
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| 121 | <TR valign=top> |
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| 122 | <TD nowrap>Copyright © 2000-2001</TD><TD> |
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| 123 | <A HREF="../../../people/jeremy_siek.htm">Jeremy Siek</A>, Indiana University (<A HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>) |
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| 124 | </TD></TR></TABLE> |
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| 125 | |
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| 126 | </BODY> |
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| 127 | </HTML> |
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