1<HTML> 2<!-- 3 Copyright (c) Jeremy Siek 2000 4 5 Distributed under the Boost Software License, Version 1.0. 6 (See accompanying file LICENSE_1_0.txt or copy at 7 http://www.boost.org/LICENSE_1_0.txt) 8 --> 9<Head> 10<Title>Boost Graph Library: Transpose Graph</Title> 11<BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b" 12 ALINK="#ff0000"> 13<IMG SRC="../../../boost.png" 14 ALT="C++ Boost" width="277" height="86"> 15 16<BR Clear> 17 18<H1><TT>transpose_graph</TT></H1> 19 20<PRE> 21template <class <a href="./VertexListGraph.html">VertexListGraph</a>, class <a href="./MutableGraph.html">MutableGraph</a>> 22void transpose_graph(const VertexListGraph& G, MutableGraph& G_T, 23 const bgl_named_params<P, T, R>& params = <i>all defaults</i>) 24</PRE> 25 26<P> 27This function computes the transpose of a directed graph. The 28transpose of a directed graph <i>G = (V, E)</i>is the graph 29<i>G<sup>T</sup> = (V, E<sup>T</sup>)</i> , where <i>E<sup>T</sup> = 30{(v, u) in V x V: (u, v) in E}</i> . i.e., <i>G<sup>T</sup></i> is 31<i>G</i> with all its edges reversed. Graph <TT>G_T</TT> passed into 32the algorithm must have no vertices and 33no edges. The vertices and edges will be added by <tt>transpose_graph()</tt> by 34calling <tt>add_vertex</tt> and <tt>add_edge</tt> as follows for each edge 35<i>(u,v)</i> in <tt>G</tt>. 36 37<H3>Example</H3> 38 39Here's an example of transposing a graph: 40<a href="../example/transpose-example.cpp"><tt>example/transpose-example.cpp</tt></a>. 41 42<H3>Where Defined</H3> 43 44<P> 45<a href="../../../boost/graph/transpose_graph.hpp"><TT>boost/graph/transpose_graph.hpp</TT></a> 46 47<P> 48 49<H3>Parameters</H3> 50 51IN: <tt>const VertexListGraph& G</tt> 52<blockquote> 53A directed graph. The graph type must be a model of <a href="./VertexListGraph.html">Vertex List Graph</a>. 54</blockquote> 55 56OUT: <tt>const MutableGraph& G_T</tt> 57<blockquote> 58The transposed graph. The graph type must be a model of <a 59href="./MutableGraph.html">Mutable Graph</a>. 60</blockquote> 61 62<h3>Named Parameters</h3> 63 64IN: <tt>vertex_copy(VertexCopier vc)</tt> 65<blockquote> 66This is a <a href="http://www.boost.org/sgi/stl/BinaryFunction.html">Binary Function</a> that copies the properties of a vertex in the original graph 67into the corresponding vertex in the copy.<br> 68 69<b>Default:</b> <tt>vertex_copier<VertexListGraph, MutableGraph></tt> 70which uses the property tag <tt>vertex_all</tt> to access a property 71map from the graph. 72</blockquote> 73 74IN: <tt>edge_copy(EdgeCopier ec)</tt> 75<blockquote> 76This is a <a href="http://www.boost.org/sgi/stl/BinaryFunction.html">Binary Function</a> that copies the properties of an edge in the original graph 77into the corresponding edge in the copy.<br> 78 79<b>Default:</b> <tt>edge_copier<VertexListGraph, MutableGraph></tt> 80which uses the property tag <tt>edge_all</tt> to access a property 81map from the graph. 82</blockquote> 83 84IN: <tt>vertex_index_map(VertexIndexMap i_map)</tt> 85<blockquote> 86The vertex index map type must be a model of <a 87href="../../property_map/doc/ReadablePropertyMap.html">Readable Property 88Map</a> and must map the vertex descriptors of <tt>G</tt> to the 89integers from 0 to <tt>num_vertices(G)</tt>.<br> 90 91<b>Default:</b> <tt>get(vertex_index, G)</tt> 92 Note: if you use this default, make sure your graph has 93 an internal <tt>vertex_index</tt> property. For example, 94 <tt>adjacency_list</tt> with <tt>VertexList=listS</tt> does 95 not have an internal <tt>vertex_index</tt> property. 96</blockquote> 97 98 99UTIL/OUT: <tt>orig_to_copy(Orig2CopyMap c)</tt> 100<blockquote> 101This maps vertices in the original graph to vertices in the copy. 102 103<b>Default:</b> an <a 104 href="../../property_map/doc/iterator_property_map.html"> 105 </tt>iterator_property_map</tt></a> created from a 106 <tt>std::vector</tt> of the output graph's vertex descriptor type of size 107 <tt>num_vertices(g)</tt> and using the <tt>i_map</tt> for the index 108 map. 109</blockquote> 110 111<H3>Complexity</H3> 112 113<P> 114The time complexity is <i>O(V + E)</i>. 115 116 117 118<br> 119<HR> 120<TABLE> 121<TR valign=top> 122<TD nowrap>Copyright © 2000-2001</TD><TD> 123<A HREF="http://www.boost.org/people/jeremy_siek.htm">Jeremy Siek</A>, Indiana University (<A HREF="mailto:jsiek@osl.iu.edu">jsiek@osl.iu.edu</A>) 124</TD></TR></TABLE> 125 126</BODY> 127</HTML> 128
