bandwidth.html 2.6 KB

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  3. Copyright (c) Jeremy Siek 2000
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  8. <Head>
  9. <Title>Boost Graph Library: Bandwidth</Title>
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  14. <BR Clear>
  15. <H1><A NAME="sec:bandwidth">
  16. <TT>bandwidth</TT>
  17. </H1>
  18. <pre>
  19. (1)
  20. template &lt;typename Graph&gt;
  21. typename graph_traits&lt;Graph&gt;::vertices_size_type
  22. bandwidth(const Graph& g)
  23. (2)
  24. template &lt;typename Graph, typename VertexIndexMap&gt;
  25. typename graph_traits&lt;Graph&gt;::vertices_size_type
  26. bandwidth(const Graph& g, VertexIndexMap index_map)
  27. </pre>
  28. The <b><i>bandwidth</i></b> of a graph is the maximum
  29. distance between two adjacent vertices, with distance measured on a
  30. line upon which the vertices have been placed at unit intervals. To
  31. put it another way, if the vertices of a graph
  32. <i>G=(V,E)</i> are each assigned an index from zero to <i>|V| - 1</i>
  33. given by <i>index[v]</i>, then the bandwidth of <i>G</i> is<br>
  34. <br>
  35. <i>B(G) = max { |index[u] - index[v]|&nbsp;&nbsp;| (u,v) in E }</i><br>
  36. <h3>Defined in</h3>
  37. <a href="../../../boost/graph/bandwidth.hpp"><tt>boost/graph/bandwidth.hpp</tt></a>
  38. <hr>
  39. <H1><A NAME="sec:ith-bandwidth">
  40. <TT>ith_bandwidth</TT>
  41. </H1>
  42. <pre>
  43. (1)
  44. template &lt;typename Graph&gt;
  45. typename graph_traits&lt;Graph&gt;::vertices_size_type
  46. ith_bandwidth(typename graph_traits&lt;Graph&gt;::vertex_descriptor i,
  47. const Graph&amp; g)
  48. (2)
  49. template &lt;typename Graph, typename VertexIndexMap&gt;
  50. typename graph_traits&lt;Graph&gt;::vertices_size_type
  51. ith_bandwidth(typename graph_traits&lt;Graph&gt;::vertex_descriptor i,
  52. const Graph&amp; g,
  53. VertexIndexMap index)
  54. </pre>
  55. The <b><i>i-th bandwidth</i></b> a graph is the maximum distance
  56. between the <i>i-th</i> vertex and any of its neighbors.<br>
  57. <br>
  58. <i>B<sub>i</sub>(G) = max { |index[i] - index[j]|&nbsp;&nbsp;| (i,j) in E }</i><br>
  59. <br>
  60. So the bandwidth <i>B(G)</i> can be expressed as the maximum
  61. of the i-th bandwidths <i>B<sub>i</sub>(G)</i>.<br>
  62. <br>
  63. <i>B(G) = max { B<sub>i</sub>(G) &nbsp;&nbsp;| i=0...|V|-1 }</i><br>
  64. <h3>Defined in</h3>
  65. <a href="../../../boost/graph/bandwidth.hpp"><tt>boost/graph/bandwidth.hpp</tt></a>
  66. <br>
  67. <HR>
  68. <TABLE>
  69. <TR valign=top>
  70. <TD nowrap>Copyright &copy; 2000-2001</TD><TD>
  71. <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>)
  72. </TD></TR></TABLE>
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