boost/libs/graph/doc/transpose_graph.html

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  10 <Title>Boost Graph Library: Transpose Graph</Title>
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  18 <H1><TT>transpose_graph</TT></H1>
  19
  20 <PRE>
  21 template &lt;class <a href="./VertexListGraph.html">VertexListGraph</a>, class <a href="./MutableGraph.html">MutableGraph</a>&gt;
  22 void transpose_graph(const VertexListGraph&amp; G, MutableGraph&amp; G_T,
  23     const bgl_named_params&lt;P, T, R&gt;&amp; params = <i>all defaults</i>)
  24 </PRE>
  25
  26 <P>
  27 This function computes the transpose of a directed graph. The
  28 transpose 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
  32 the algorithm must have no vertices and
  33 no edges. The vertices and edges will be added by <tt>transpose_graph()</tt> by
  34 calling <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
  39 Here'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
  51 IN: <tt>const VertexListGraph&amp; G</tt>
  52 <blockquote>
  53 A directed graph. The graph type must be a model of <a href="./VertexListGraph.html">Vertex List Graph</a>.
  54 </blockquote>
  55
  56 OUT: <tt>const MutableGraph&amp; G_T</tt>
  57 <blockquote>
  58 The transposed graph.  The graph type must be a model of <a
  59 href="./MutableGraph.html">Mutable Graph</a>.
  60 </blockquote>
  61
  62 <h3>Named Parameters</h3>
  63
  64 IN: <tt>vertex_copy(VertexCopier vc)</tt>
  65 <blockquote>
  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
  67 into the corresponding vertex in the copy.<br>
  68
  69 <b>Default:</b> <tt>vertex_copier&lt;VertexListGraph, MutableGraph&gt;</tt>
  70 which uses the property tag <tt>vertex_all</tt> to access a property
  71 map from the graph.
  72 </blockquote>
  73
  74 IN: <tt>edge_copy(EdgeCopier ec)</tt>
  75 <blockquote>
  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
  77 into the corresponding edge in the copy.<br>
  78
  79 <b>Default:</b> <tt>edge_copier&lt;VertexListGraph, MutableGraph&gt;</tt>
  80 which uses the property tag <tt>edge_all</tt> to access a property
  81 map from the graph.
  82 </blockquote>
  83
  84 IN: <tt>vertex_index_map(VertexIndexMap i_map)</tt>
  85 <blockquote>
  86 The vertex index map type must be a model of <a
  87 href="../../property_map/ReadablePropertyMap.html">Readable Property
  88 Map</a> and must map the vertex descriptors of <tt>G</tt> to the
  89 integers 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>adjacenty_list</tt> with <tt>VertexList=listS</tt> does
  95     not have an internal <tt>vertex_index</tt> property.
  96 </blockquote>
  97
  98
  99 UTIL/OUT: <tt>orig_to_copy(Orig2CopyMap c)</tt>
 100 <blockquote>
 101 This maps vertices in the original graph to vertices in the copy.
 102
 103 <b>Default:</b> an <a
 104   href="../../property_map/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>
 114 The 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 &copy 2000-2001</TD><TD>
 123 <A HREF="../../../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>
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