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--></script> <div id="nav-path" class="navpath"> <ul> <li class="navelem"><a class="el" href="dir_f5421e52a658cd938113ed6044324834.html">src</a> </li> <li class="navelem"><a class="el" href="dir_ae92c2ff78847f0cb49b545f9089bbbc.html">ompl</a> </li> <li class="navelem"><a class="el" href="dir_bcc018587a1660af6e54d7cc713e88f2.html">datastructures</a> </li> </ul> </div> </div> <div class="header"> <div class="headertitle"> <div class="title">GreedyKCenters.h</div> </div> </div> <div class="contents"> <div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">/*********************************************************************</span> <a name="l00002"></a>00002 <span class="comment">* Software License Agreement (BSD License)</span> <a name="l00003"></a>00003 <span class="comment">*</span> <a name="l00004"></a>00004 <span class="comment">* Copyright (c) 2011, Rice University</span> <a name="l00005"></a>00005 <span class="comment">* All rights reserved.</span> <a name="l00006"></a>00006 <span class="comment">*</span> <a name="l00007"></a>00007 <span class="comment">* Redistribution and use in source and binary forms, with or without</span> <a name="l00008"></a>00008 <span class="comment">* modification, are permitted provided that the following conditions</span> <a name="l00009"></a>00009 <span class="comment">* are met:</span> <a name="l00010"></a>00010 <span class="comment">*</span> <a name="l00011"></a>00011 <span class="comment">* * Redistributions of source code must retain the above copyright</span> <a name="l00012"></a>00012 <span class="comment">* notice, this list of conditions and the following disclaimer.</span> <a name="l00013"></a>00013 <span class="comment">* * Redistributions in binary form must reproduce the above</span> <a name="l00014"></a>00014 <span class="comment">* copyright notice, this list of conditions and the following</span> <a name="l00015"></a>00015 <span class="comment">* disclaimer in the documentation and/or other materials provided</span> <a name="l00016"></a>00016 <span class="comment">* with the distribution.</span> <a name="l00017"></a>00017 <span class="comment">* * Neither the name of the Rice University nor the names of its</span> <a name="l00018"></a>00018 <span class="comment">* contributors may be used to endorse or promote products derived</span> <a name="l00019"></a>00019 <span class="comment">* from this software without specific prior written permission.</span> <a name="l00020"></a>00020 <span class="comment">*</span> <a name="l00021"></a>00021 <span class="comment">* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS</span> <a name="l00022"></a>00022 <span class="comment">* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT</span> <a name="l00023"></a>00023 <span class="comment">* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS</span> <a name="l00024"></a>00024 <span class="comment">* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE</span> <a name="l00025"></a>00025 <span class="comment">* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,</span> <a name="l00026"></a>00026 <span class="comment">* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,</span> <a name="l00027"></a>00027 <span class="comment">* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;</span> <a name="l00028"></a>00028 <span class="comment">* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER</span> <a name="l00029"></a>00029 <span class="comment">* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT</span> <a name="l00030"></a>00030 <span class="comment">* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN</span> <a name="l00031"></a>00031 <span class="comment">* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE</span> <a name="l00032"></a>00032 <span class="comment">* POSSIBILITY OF SUCH DAMAGE.</span> <a name="l00033"></a>00033 <span class="comment">*********************************************************************/</span> <a name="l00034"></a>00034 <a name="l00035"></a>00035 <span class="comment">/* Author: Mark Moll */</span> <a name="l00036"></a>00036 <a name="l00037"></a>00037 <span class="preprocessor">#ifndef OMPL_DATASTRUCTURES_GREEDY_K_CENTERS_</span> <a name="l00038"></a>00038 <span class="preprocessor"></span><span class="preprocessor">#define OMPL_DATASTRUCTURES_GREEDY_K_CENTERS_</span> <a name="l00039"></a>00039 <span class="preprocessor"></span> <a name="l00040"></a>00040 <span class="preprocessor">#include "ompl/util/RandomNumbers.h"</span> <a name="l00041"></a>00041 <a name="l00042"></a>00042 <span class="keyword">namespace </span>ompl <a name="l00043"></a>00043 { <a name="l00047"></a>00047 <span class="keyword">template</span><<span class="keyword">typename</span> _T> <a name="l00048"></a><a class="code" href="classompl_1_1GreedyKCenters.html">00048</a> <span class="keyword">class </span><a class="code" href="classompl_1_1GreedyKCenters.html" title="An instance of this class can be used to greedily select a given number of representatives from a set...">GreedyKCenters</a> <a name="l00049"></a>00049 { <a name="l00050"></a>00050 <span class="keyword">public</span>: <a name="l00052"></a><a class="code" href="classompl_1_1GreedyKCenters.html#a244fad14a2118b60ec969d2beb7b0194">00052</a> <span class="keyword">typedef</span> boost::function2<double, const _T&, const _T&> <a class="code" href="classompl_1_1GreedyKCenters.html#a244fad14a2118b60ec969d2beb7b0194" title="The definition of a distance function.">DistanceFunction</a>; <a name="l00053"></a>00053 <a name="l00054"></a>00054 <a class="code" href="classompl_1_1GreedyKCenters.html" title="An instance of this class can be used to greedily select a given number of representatives from a set...">GreedyKCenters</a>(<span class="keywordtype">void</span>) <a name="l00055"></a>00055 { <a name="l00056"></a>00056 } <a name="l00057"></a>00057 <a name="l00058"></a>00058 <span class="keyword">virtual</span> ~<a class="code" href="classompl_1_1GreedyKCenters.html" title="An instance of this class can be used to greedily select a given number of representatives from a set...">GreedyKCenters</a>(<span class="keywordtype">void</span>) <a name="l00059"></a>00059 { <a name="l00060"></a>00060 } <a name="l00061"></a>00061 <a name="l00063"></a><a class="code" href="classompl_1_1GreedyKCenters.html#aa46b77a69db20e4c411bbb85956eab21">00063</a> <span class="keywordtype">void</span> <a class="code" href="classompl_1_1GreedyKCenters.html#aa46b77a69db20e4c411bbb85956eab21" title="Set the distance function to use.">setDistanceFunction</a>(<span class="keyword">const</span> <a class="code" href="classompl_1_1GreedyKCenters.html#a244fad14a2118b60ec969d2beb7b0194" title="The definition of a distance function.">DistanceFunction</a> &distFun) <a name="l00064"></a>00064 { <a name="l00065"></a>00065 <a class="code" href="classompl_1_1GreedyKCenters.html#a4c617a02bb7489b3d1e32261f099f113" title="The used distance function.">distFun_</a> = distFun; <a name="l00066"></a>00066 } <a name="l00067"></a>00067 <a name="l00069"></a><a class="code" href="classompl_1_1GreedyKCenters.html#ad38037a0f3f7c23ce9175e8eedfa5dcd">00069</a> <span class="keyword">const</span> <a class="code" href="classompl_1_1GreedyKCenters.html#a244fad14a2118b60ec969d2beb7b0194" title="The definition of a distance function.">DistanceFunction</a>& <a class="code" href="classompl_1_1GreedyKCenters.html#ad38037a0f3f7c23ce9175e8eedfa5dcd" title="Get the distance function used.">getDistanceFunction</a>(<span class="keywordtype">void</span>)<span class="keyword"> const</span> <a name="l00070"></a>00070 <span class="keyword"> </span>{ <a name="l00071"></a>00071 <span class="keywordflow">return</span> <a class="code" href="classompl_1_1GreedyKCenters.html#a4c617a02bb7489b3d1e32261f099f113" title="The used distance function.">distFun_</a>; <a name="l00072"></a>00072 } <a name="l00073"></a>00073 <a name="l00082"></a><a class="code" href="classompl_1_1GreedyKCenters.html#a1e1aa026ec5c4833183846fd95ea2b57">00082</a> <span class="keywordtype">void</span> <a class="code" href="classompl_1_1GreedyKCenters.html#a1e1aa026ec5c4833183846fd95ea2b57" title="Greedy algorithm for selecting k centers.">kcenters</a>(<span class="keyword">const</span> std::vector<_T>& data, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> k, <a name="l00083"></a>00083 std::vector<unsigned int>& centers, std::vector<std::vector<double> >& dists) <a name="l00084"></a>00084 { <a name="l00085"></a>00085 <span class="comment">// array containing the minimum distance between each data point</span> <a name="l00086"></a>00086 <span class="comment">// and the centers computed so far</span> <a name="l00087"></a>00087 std::vector<double> minDist(data.size(), std::numeric_limits<double>::infinity()); <a name="l00088"></a>00088 <a name="l00089"></a>00089 centers.clear(); <a name="l00090"></a>00090 centers.reserve(k); <a name="l00091"></a>00091 dists.resize(data.size(), std::vector<double>(k)); <a name="l00092"></a>00092 <span class="comment">// first center is picked randomly</span> <a name="l00093"></a>00093 centers.push_back(<a class="code" href="classompl_1_1GreedyKCenters.html#a9f9f1e9cacc57cc0a7c1526406cc94dd">rng_</a>.<a class="code" href="classompl_1_1RNG.html#ad122fd3309d2a2c72ca1dd665c1a2803" title="Generate a random integer within given bounds: [lower_bound, upper_bound].">uniformInt</a>(0, data.size() - 1)); <a name="l00094"></a>00094 <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> i=1; i<k; ++i) <a name="l00095"></a>00095 { <a name="l00096"></a>00096 <span class="keywordtype">unsigned</span> ind; <a name="l00097"></a>00097 <span class="keyword">const</span> _T& center = data[centers[i - 1]]; <a name="l00098"></a>00098 <span class="keywordtype">double</span> maxDist = -std::numeric_limits<double>::infinity(); <a name="l00099"></a>00099 <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> j=0; j<data.size(); ++j) <a name="l00100"></a>00100 { <a name="l00101"></a>00101 <span class="keywordflow">if</span> ((dists[j][i-1] = <a class="code" href="classompl_1_1GreedyKCenters.html#a4c617a02bb7489b3d1e32261f099f113" title="The used distance function.">distFun_</a>(data[j], center)) < minDist[j]) <a name="l00102"></a>00102 minDist[j] = dists[j][i - 1]; <a name="l00103"></a>00103 <span class="comment">// the j-th center is the one furthest away from center 0,..,j-1</span> <a name="l00104"></a>00104 <span class="keywordflow">if</span> (minDist[j] > maxDist) <a name="l00105"></a>00105 { <a name="l00106"></a>00106 ind = j; <a name="l00107"></a>00107 maxDist = minDist[j]; <a name="l00108"></a>00108 } <a name="l00109"></a>00109 } <a name="l00110"></a>00110 <span class="comment">// no more centers available</span> <a name="l00111"></a>00111 <span class="keywordflow">if</span> (maxDist < std::numeric_limits<double>::epsilon()) <span class="keywordflow">break</span>; <a name="l00112"></a>00112 centers.push_back(ind); <a name="l00113"></a>00113 } <a name="l00114"></a>00114 <a name="l00115"></a>00115 <span class="keyword">const</span> _T& center = data[centers.back()]; <a name="l00116"></a>00116 <span class="keywordtype">unsigned</span> i = centers.size() - 1; <a name="l00117"></a>00117 <span class="keywordflow">for</span> (<span class="keywordtype">unsigned</span> j = 0; j < data.size(); ++j) <a name="l00118"></a>00118 dists[j][i] = <a class="code" href="classompl_1_1GreedyKCenters.html#a4c617a02bb7489b3d1e32261f099f113" title="The used distance function.">distFun_</a>(data[j], center); <a name="l00119"></a>00119 } <a name="l00120"></a>00120 <a name="l00121"></a>00121 <span class="keyword">protected</span>: <a name="l00123"></a><a class="code" href="classompl_1_1GreedyKCenters.html#a4c617a02bb7489b3d1e32261f099f113">00123</a> <a class="code" href="classompl_1_1GreedyKCenters.html#a244fad14a2118b60ec969d2beb7b0194" title="The definition of a distance function.">DistanceFunction</a> <a class="code" href="classompl_1_1GreedyKCenters.html#a4c617a02bb7489b3d1e32261f099f113" title="The used distance function.">distFun_</a>; <a name="l00124"></a>00124 <a name="l00126"></a><a class="code" href="classompl_1_1GreedyKCenters.html#a9f9f1e9cacc57cc0a7c1526406cc94dd">00126</a> <a class="code" href="classompl_1_1RNG.html" title="Random number generation. An instance of this class cannot be used by multiple threads at once (membe...">RNG</a> <a class="code" href="classompl_1_1GreedyKCenters.html#a9f9f1e9cacc57cc0a7c1526406cc94dd">rng_</a>; <a name="l00127"></a>00127 }; <a name="l00128"></a>00128 } <a name="l00129"></a>00129 <a name="l00130"></a>00130 <span class="preprocessor">#endif</span> </pre></div></div> </div> <!-- window showing the filter options --> <div id="MSearchSelectWindow" onmouseover="return searchBox.OnSearchSelectShow()" onmouseout="return searchBox.OnSearchSelectHide()" onkeydown="return searchBox.OnSearchSelectKey(event)"> <a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(0)"><span class="SelectionMark"> </span>All</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(1)"><span class="SelectionMark"> </span>Classes</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(2)"><span class="SelectionMark"> </span>Namespaces</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(3)"><span class="SelectionMark"> </span>Functions</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(4)"><span class="SelectionMark"> </span>Variables</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(5)"><span class="SelectionMark"> </span>Typedefs</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(6)"><span class="SelectionMark"> </span>Enumerations</a><a class="SelectItem" href="javascript:void(0)" onclick="searchBox.OnSelectItem(7)"><span class="SelectionMark"> </span>Enumerator</a></div> <!-- iframe showing the search results (closed by default) --> <div id="MSearchResultsWindow"> <iframe src="javascript:void(0)" frameborder="0" name="MSearchResults" id="MSearchResults"> </iframe> </div> </div> <div class="footer span-22 push-2 last"> <a href="http://www.kavrakilab.org">Physical and Biological Computing Group</a> • <a href="http://www.cs.rice.edu">Department of Computer Science</a> • <a href="http://www.rice.edu">Rice University</a><br> <div class="gray">Generated on Sun Oct 9 2011 23:04:40 by <a href="http://www.doxygen.org/index.html">doxygen</a> 1.7.4</div> </div> </div> </body> </html>