1<HTML> 2<!-- 3 Copyright (c) 2004 Kris Beevers 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: astar_heuristic</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> 19<pre> 20astar_heuristic<Graph, CostType> 21</pre> 22</H1> 23 24This class is a default implementation of the <a 25href="./AStarHeuristic.html">AStarHeuristic</a> concept. It 26implements a "zero" heuristic -- a heuristic function that returns a 27cost of zero regardless of the vertex it is passed. 28 29<h3>Model of</h3> 30 31<a href="./AStarHeuristic.html">AStarHeuristic</a> 32 33<H3>Template Parameters</H3> 34 35<P> 36<TABLE border> 37<TR> 38<th>Parameter</th><th>Description</th><th>Default</th> 39</tr> 40 41<TR><TD><TT>Graph</TT></TD> 42<TD> 43The type of the graph being searched. 44</TD> 45<TD></TD> 46</TR> 47 48<TR><TD><TT>CostType</TT></TD> 49<TD> 50A type that can be used with the <tt>compare</tt> and 51<tt>combine</tt> functions passed to A*. Typically an integer or 52floating point type. 53</TD> 54<TD></TD> 55</TR> 56 57</table> 58 59<H3>Where Defined</H3> 60 61<P> 62<a href="../../../boost/graph/astar_search.hpp"> 63<TT>boost/graph/astar_search.hpp</TT></a> 64 65<h3>Member Functions</h3> 66 67This class implements the single member function required by <a 68href="./AStarHeuristic.html">AStarHeuristic</a>: 69 70<table border> 71<tr> 72<th>Function</th><th>Description</th> 73</tr> 74 75<tr><td><tt> 76CostType operator()(graph_traits<Graph>::vertex_descriptor u); 77</tt></td><td> 78Called for the target of every out edge of a vertex being examined. 79Returns the cost, estimated by the heuristic, from vertex <tt>u</tt> 80to a goal. 81</td></tr> 82 83</table> 84 85<br> 86<HR> 87<TABLE> 88<TR valign=top> 89<TD nowrap>Copyright © 2004</TD><TD> 90<A HREF="http://cs.krisbeevers.com/">Kristopher Beevers</A>, 91Rensselaer Polytechnic Institute (<A 92HREF="mailto:beevek@cs.rpi.edu">beevek@cs.rpi.edu</A>) 93</TD></TR></TABLE> 94 95</BODY> 96</HTML> 97
