1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>nearest(Geometry const &, unsigned)</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Geometry"> 8<link rel="up" href="../group__predicates.html" title="Predicates (boost::geometry::index::)"> 9<link rel="prev" href="satisfies_unarypredicate_const___.html" title="satisfies(UnaryPredicate const &)"> 10<link rel="next" href="../../srs.html" title="SRS"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="satisfies_unarypredicate_const___.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../group__predicates.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../srs.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_"></a><a name="group__predicates_1ga8772d9d3e5b12b3292f7d94d47310e3e"></a><a class="link" href="nearest_geometry_const____unsigned_.html" title="nearest(Geometry const &, unsigned)">nearest(Geometry 28 const &, unsigned)</a> 29</h5></div></div></div> 30<p> 31 <a class="indexterm" name="idm45635672004144"></a> 32Generate <a class="link" href="nearest_geometry_const____unsigned_.html#group__predicates_1ga8772d9d3e5b12b3292f7d94d47310e3e">nearest()</a> 33 predicate. 34 </p> 35<h6> 36<a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.h0"></a> 37 <span class="phrase"><a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.description"></a></span><a class="link" href="nearest_geometry_const____unsigned_.html#geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.description">Description</a> 38 </h6> 39<p> 40 When nearest predicate is passed to the query, k-nearest neighbour search 41 will be performed. <code class="literal"><a class="link" href="nearest_geometry_const____unsigned_.html#group__predicates_1ga8772d9d3e5b12b3292f7d94d47310e3e">nearest()</a></code> 42 predicate takes a <code class="literal"><code class="computeroutput"><span class="identifier">Geometry</span></code></code> 43 from which distances to <code class="literal"><code class="computeroutput"><span class="identifier">Values</span></code></code> 44 are calculated and the maximum number of <code class="literal"><code class="computeroutput"><span class="identifier">Values</span></code></code> 45 that should be returned. Internally boost::geometry::comparable_distance() 46 is used to perform the calculation. 47 </p> 48<h6> 49<a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.h1"></a> 50 <span class="phrase"><a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.synopsis"></a></span><a class="link" href="nearest_geometry_const____unsigned_.html#geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.synopsis">Synopsis</a> 51 </h6> 52<pre class="programlisting"><code class="computeroutput"><span class="keyword">template</span><span class="special"><</span></code><code class="computeroutput"><span class="keyword">typename</span> <span class="identifier">Geometry</span></code><code class="computeroutput"><span class="special">></span></code> 53<span class="emphasis"><em>unspecified</em></span> <code class="computeroutput"><span class="identifier">nearest</span></code><code class="computeroutput"><span class="special">(</span></code><code class="computeroutput"><span class="identifier">Geometry</span> <span class="keyword">const</span> <span class="special">&</span></code> <code class="computeroutput"><span class="identifier">geometry</span></code><code class="computeroutput"><span class="special">,</span></code> <code class="computeroutput"><span class="keyword">unsigned</span></code> <code class="computeroutput"><span class="identifier">k</span></code><code class="computeroutput"><span class="special">)</span></code> 54</pre> 55<h6> 56<a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.h2"></a> 57 <span class="phrase"><a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.parameter_s_"></a></span><a class="link" href="nearest_geometry_const____unsigned_.html#geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.parameter_s_">Parameter(s)</a> 58 </h6> 59<div class="informaltable"><table class="table"> 60<colgroup> 61<col> 62<col> 63<col> 64</colgroup> 65<thead><tr> 66<th> 67 <p> 68 Type 69 </p> 70 </th> 71<th> 72 <p> 73 Name 74 </p> 75 </th> 76<th> 77 <p> 78 Description 79 </p> 80 </th> 81</tr></thead> 82<tbody> 83<tr> 84<td> 85 <p> 86 <code class="computeroutput"><span class="identifier">Geometry</span> <span class="keyword">const</span> 87 <span class="special">&</span></code> 88 </p> 89 </td> 90<td> 91 <p> 92 <code class="computeroutput"><span class="identifier">geometry</span></code> 93 </p> 94 </td> 95<td> 96 <p> 97 The geometry from which distance is calculated. 98 </p> 99 </td> 100</tr> 101<tr> 102<td> 103 <p> 104 <code class="computeroutput"><span class="keyword">unsigned</span></code> 105 </p> 106 </td> 107<td> 108 <p> 109 <code class="computeroutput"><span class="identifier">k</span></code> 110 </p> 111 </td> 112<td> 113 <p> 114 The maximum number of values to return. 115 </p> 116 </td> 117</tr> 118</tbody> 119</table></div> 120<h6> 121<a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.h3"></a> 122 <span class="phrase"><a name="geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.example"></a></span><a class="link" href="nearest_geometry_const____unsigned_.html#geometry.reference.spatial_indexes.group__predicates.nearest_geometry_const____unsigned_.example">Example</a> 123 </h6> 124<p> 125</p> 126<pre class="programlisting"><span class="identifier">bgi</span><span class="special">::</span><span class="identifier">query</span><span class="special">(</span><span class="identifier">spatial_index</span><span class="special">,</span> <span class="identifier">bgi</span><span class="special">::</span><span class="identifier">nearest</span><span class="special">(</span><span class="identifier">pt</span><span class="special">,</span> <span class="number">5</span><span class="special">),</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">back_inserter</span><span class="special">(</span><span class="identifier">result</span><span class="special">));</span> 127<span class="identifier">bgi</span><span class="special">::</span><span class="identifier">query</span><span class="special">(</span><span class="identifier">spatial_index</span><span class="special">,</span> <span class="identifier">bgi</span><span class="special">::</span><span class="identifier">nearest</span><span class="special">(</span><span class="identifier">pt</span><span class="special">,</span> <span class="number">5</span><span class="special">)</span> <span class="special">&&</span> <span class="identifier">bgi</span><span class="special">::</span><span class="identifier">intersects</span><span class="special">(</span><span class="identifier">box</span><span class="special">),</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">back_inserter</span><span class="special">(</span><span class="identifier">result</span><span class="special">));</span> 128<span class="identifier">bgi</span><span class="special">::</span><span class="identifier">query</span><span class="special">(</span><span class="identifier">spatial_index</span><span class="special">,</span> <span class="identifier">bgi</span><span class="special">::</span><span class="identifier">nearest</span><span class="special">(</span><span class="identifier">box</span><span class="special">,</span> <span class="number">5</span><span class="special">),</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">back_inserter</span><span class="special">(</span><span class="identifier">result</span><span class="special">));</span> 129</pre> 130<p> 131 </p> 132<div class="warning"><table border="0" summary="Warning"> 133<tr> 134<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../../doc/src/images/warning.png"></td> 135<th align="left">Warning</th> 136</tr> 137<tr><td align="left" valign="top"><p> 138 Only one <code class="literal"><a class="link" href="nearest_geometry_const____unsigned_.html#group__predicates_1ga8772d9d3e5b12b3292f7d94d47310e3e">nearest()</a></code> 139 predicate may be used in a query. 140 </p></td></tr> 141</table></div> 142</div> 143<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 144<td align="left"></td> 145<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 146 Wulkiewicz, Oracle and/or its affiliates<p> 147 Distributed under the Boost Software License, Version 1.0. (See accompanying 148 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 149 </p> 150</div></td> 151</tr></table> 152<hr> 153<div class="spirit-nav"> 154<a accesskey="p" href="satisfies_unarypredicate_const___.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../group__predicates.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../../srs.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 155</div> 156</body> 157</html> 158
