<HTML> <!-- Copyright (c) Jeremy Siek 2000 Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) --> <Head> <Title>Boost Graph Library: Transpose Graph</Title> <BODY BGCOLOR="#ffffff" LINK="#0000ee" TEXT="#000000" VLINK="#551a8b" ALINK="#ff0000"> <IMG SRC="../../../boost.png" ALT="C++ Boost" width="277" height="86"> <BR Clear> <H1><TT>transpose_graph</TT></H1> <PRE> template <class <a href="./VertexListGraph.html">VertexListGraph</a>, class <a href="./MutableGraph.html">MutableGraph</a>> void transpose_graph(const VertexListGraph& G, MutableGraph& G_T, const bgl_named_params<P, T, R>& params = <i>all defaults</i>) </PRE> <P> This function computes the transpose of a directed graph. The transpose of a directed graph <i>G = (V, E)</i>is the graph <i>G<sup>T</sup> = (V, E<sup>T</sup>)</i> , where <i>E<sup>T</sup> = {(v, u) in V x V: (u, v) in E}</i> . i.e., <i>G<sup>T</sup></i> is <i>G</i> with all its edges reversed. Graph <TT>G_T</TT> passed into the algorithm must have no vertices and no edges. The vertices and edges will be added by <tt>transpose_graph()</tt> by calling <tt>add_vertex</tt> and <tt>add_edge</tt> as follows for each edge <i>(u,v)</i> in <tt>G</tt>. <H3>Example</H3> Here's an example of transposing a graph: <a href="../example/transpose-example.cpp"><tt>example/transpose-example.cpp</tt></a>. <H3>Where Defined</H3> <P> <a href="../../../boost/graph/transpose_graph.hpp"><TT>boost/graph/transpose_graph.hpp</TT></a> <P> <H3>Parameters</H3> IN: <tt>const VertexListGraph& G</tt> <blockquote> A directed graph. The graph type must be a model of <a href="./VertexListGraph.html">Vertex List Graph</a>. </blockquote> OUT: <tt>const MutableGraph& G_T</tt> <blockquote> The transposed graph. The graph type must be a model of <a href="./MutableGraph.html">Mutable Graph</a>. </blockquote> <h3>Named Parameters</h3> IN: <tt>vertex_copy(VertexCopier vc)</tt> <blockquote> 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 into the corresponding vertex in the copy.<br> <b>Default:</b> <tt>vertex_copier<VertexListGraph, MutableGraph></tt> which uses the property tag <tt>vertex_all</tt> to access a property map from the graph. </blockquote> IN: <tt>edge_copy(EdgeCopier ec)</tt> <blockquote> 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 into the corresponding edge in the copy.<br> <b>Default:</b> <tt>edge_copier<VertexListGraph, MutableGraph></tt> which uses the property tag <tt>edge_all</tt> to access a property map from the graph. </blockquote> IN: <tt>vertex_index_map(VertexIndexMap i_map)</tt> <blockquote> The vertex index map type must be a model of <a href="../../property_map/doc/ReadablePropertyMap.html">Readable Property Map</a> and must map the vertex descriptors of <tt>G</tt> to the integers from 0 to <tt>num_vertices(G)</tt>.<br> <b>Default:</b> <tt>get(vertex_index, G)</tt> Note: if you use this default, make sure your graph has an internal <tt>vertex_index</tt> property. For example, <tt>adjacenty_list</tt> with <tt>VertexList=listS</tt> does not have an internal <tt>vertex_index</tt> property. </blockquote> UTIL/OUT: <tt>orig_to_copy(Orig2CopyMap c)</tt> <blockquote> This maps vertices in the original graph to vertices in the copy. <b>Default:</b> an <a href="../../property_map/doc/iterator_property_map.html"> </tt>iterator_property_map</tt></a> created from a <tt>std::vector</tt> of the output graph's vertex descriptor type of size <tt>num_vertices(g)</tt> and using the <tt>i_map</tt> for the index map. </blockquote> <H3>Complexity</H3> <P> The time complexity is <i>O(V + E)</i>. <br> <HR> <TABLE> <TR valign=top> <TD nowrap>Copyright © 2000-2001</TD><TD> <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>) </TD></TR></TABLE> </BODY> </HTML>