1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>return_centroid</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="../centroid.html" title="centroid"> 9<link rel="prev" href="centroid_2.html" title="centroid"> 10<link rel="next" href="return_centroid_2_with_strategy.html" title="return_centroid (with strategy)"> 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="centroid_2.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../centroid.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="return_centroid_2_with_strategy.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.algorithms.centroid.return_centroid_1"></a><a class="link" href="return_centroid_1.html" title="return_centroid">return_centroid</a> 28</h5></div></div></div> 29<p> 30 <a class="indexterm" name="idm45635705421872"></a> 31Calculates the centroid of a geometry. 32 </p> 33<h6> 34<a name="geometry.reference.algorithms.centroid.return_centroid_1.h0"></a> 35 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.description"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.description">Description</a> 36 </h6> 37<p> 38 The free function centroid calculates the geometric center (or: center 39 of mass) of a geometry. This version with the return_ prefix returns 40 the centroid, and a template parameter must therefore be specified in 41 the call.. 42 </p> 43<h6> 44<a name="geometry.reference.algorithms.centroid.return_centroid_1.h1"></a> 45 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.synopsis"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.synopsis">Synopsis</a> 46 </h6> 47<p> 48</p> 49<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Point</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">></span> 50<span class="identifier">Point</span> <span class="identifier">return_centroid</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="keyword">const</span> <span class="special">&</span> <span class="identifier">geometry</span><span class="special">)</span></pre> 51<p> 52 </p> 53<h6> 54<a name="geometry.reference.algorithms.centroid.return_centroid_1.h2"></a> 55 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.parameters"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.parameters">Parameters</a> 56 </h6> 57<div class="informaltable"><table class="table"> 58<colgroup> 59<col> 60<col> 61<col> 62<col> 63</colgroup> 64<thead><tr> 65<th> 66 <p> 67 Type 68 </p> 69 </th> 70<th> 71 <p> 72 Concept 73 </p> 74 </th> 75<th> 76 <p> 77 Name 78 </p> 79 </th> 80<th> 81 <p> 82 Description 83 </p> 84 </th> 85</tr></thead> 86<tbody> 87<tr> 88<td> 89 <p> 90 Point 91 </p> 92 </td> 93<td> 94 <p> 95 Any type fulfilling a Point Concept 96 </p> 97 </td> 98<td> 99 <p> 100 - 101 </p> 102 </td> 103<td> 104 <p> 105 Must be specified 106 </p> 107 </td> 108</tr> 109<tr> 110<td> 111 <p> 112 Geometry const & 113 </p> 114 </td> 115<td> 116 <p> 117 Any type fulfilling a Geometry Concept 118 </p> 119 </td> 120<td> 121 <p> 122 geometry 123 </p> 124 </td> 125<td> 126 <p> 127 A model of the specified concept 128 </p> 129 </td> 130</tr> 131</tbody> 132</table></div> 133<h6> 134<a name="geometry.reference.algorithms.centroid.return_centroid_1.h3"></a> 135 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.returns"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.returns">Returns</a> 136 </h6> 137<p> 138 The calculated centroid 139 </p> 140<h6> 141<a name="geometry.reference.algorithms.centroid.return_centroid_1.h4"></a> 142 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.header"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.header">Header</a> 143 </h6> 144<p> 145 Either 146 </p> 147<p> 148 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 149 </p> 150<p> 151 Or 152 </p> 153<p> 154 <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">algorithms</span><span class="special">/</span><span class="identifier">centroid</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> 155 </p> 156<h6> 157<a name="geometry.reference.algorithms.centroid.return_centroid_1.h5"></a> 158 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.conformance"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.conformance">Conformance</a> 159 </h6> 160<p> 161 The function centroid implements function Centroid from the <a href="http://www.opengeospatial.org/standards/sfa" target="_top">OGC 162 Simple Feature Specification</a>. 163 </p> 164<h6> 165<a name="geometry.reference.algorithms.centroid.return_centroid_1.h6"></a> 166 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.behavior"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.behavior">Behavior</a> 167 </h6> 168<div class="informaltable"><table class="table"> 169<colgroup> 170<col> 171<col> 172</colgroup> 173<thead><tr> 174<th> 175 <p> 176 Case 177 </p> 178 </th> 179<th> 180 <p> 181 Behavior 182 </p> 183 </th> 184</tr></thead> 185<tbody> 186<tr> 187<td> 188 <p> 189 Point 190 </p> 191 </td> 192<td> 193 <p> 194 Returns the point itself as the centroid 195 </p> 196 </td> 197</tr> 198<tr> 199<td> 200 <p> 201 Multi Point 202 </p> 203 </td> 204<td> 205 <p> 206 Calculates centroid (based on average) 207 </p> 208 </td> 209</tr> 210<tr> 211<td> 212 <p> 213 linear (e.g. linestring) 214 </p> 215 </td> 216<td> 217 <p> 218 Calculates centroid (based on weighted length) 219 </p> 220 </td> 221</tr> 222<tr> 223<td> 224 <p> 225 areal (e.g. polygon) 226 </p> 227 </td> 228<td> 229 <p> 230 Calculates centroid 231 </p> 232 </td> 233</tr> 234<tr> 235<td> 236 <p> 237 Empty (e.g. polygon without points) 238 </p> 239 </td> 240<td> 241 <p> 242 Throws a <a class="link" href="../../exceptions/centroid_exception.html" title="centroid_exception">centroid_exception</a> 243 </p> 244 </td> 245</tr> 246<tr> 247<td> 248 <p> 249 Cartesian 250 </p> 251 </td> 252<td> 253 <p> 254 Implemented 255 </p> 256 </td> 257</tr> 258<tr> 259<td> 260 <p> 261 Spherical 262 </p> 263 </td> 264<td> 265 <p> 266 Calculates the centroid as if based on Cartesian coordinates 267 </p> 268 </td> 269</tr> 270</tbody> 271</table></div> 272<h6> 273<a name="geometry.reference.algorithms.centroid.return_centroid_1.h7"></a> 274 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.supported_geometries"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.supported_geometries">Supported 275 geometries</a> 276 </h6> 277<div class="informaltable"><table class="table"> 278<colgroup> 279<col> 280<col> 281<col> 282</colgroup> 283<thead><tr> 284<th> 285 </th> 286<th> 287 <p> 288 2D 289 </p> 290 </th> 291<th> 292 <p> 293 3D 294 </p> 295 </th> 296</tr></thead> 297<tbody> 298<tr> 299<td> 300 <p> 301 Point 302 </p> 303 </td> 304<td> 305 <p> 306 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 307 </p> 308 </td> 309<td> 310 <p> 311 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 312 </p> 313 </td> 314</tr> 315<tr> 316<td> 317 <p> 318 Segment 319 </p> 320 </td> 321<td> 322 <p> 323 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 324 </p> 325 </td> 326<td> 327 <p> 328 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 329 </p> 330 </td> 331</tr> 332<tr> 333<td> 334 <p> 335 Box 336 </p> 337 </td> 338<td> 339 <p> 340 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 341 </p> 342 </td> 343<td> 344 <p> 345 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 346 </p> 347 </td> 348</tr> 349<tr> 350<td> 351 <p> 352 Linestring 353 </p> 354 </td> 355<td> 356 <p> 357 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 358 </p> 359 </td> 360<td> 361 <p> 362 <span class="inlinemediaobject"><img src="../../../../img/nyi.png" alt="nyi"></span> 363 </p> 364 </td> 365</tr> 366<tr> 367<td> 368 <p> 369 Ring 370 </p> 371 </td> 372<td> 373 <p> 374 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 375 </p> 376 </td> 377<td> 378 <p> 379 <span class="inlinemediaobject"><img src="../../../../img/nyi.png" alt="nyi"></span> 380 </p> 381 </td> 382</tr> 383<tr> 384<td> 385 <p> 386 Polygon 387 </p> 388 </td> 389<td> 390 <p> 391 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 392 </p> 393 </td> 394<td> 395 <p> 396 <span class="inlinemediaobject"><img src="../../../../img/nyi.png" alt="nyi"></span> 397 </p> 398 </td> 399</tr> 400<tr> 401<td> 402 <p> 403 MultiPoint 404 </p> 405 </td> 406<td> 407 <p> 408 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 409 </p> 410 </td> 411<td> 412 <p> 413 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 414 </p> 415 </td> 416</tr> 417<tr> 418<td> 419 <p> 420 MultiLinestring 421 </p> 422 </td> 423<td> 424 <p> 425 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 426 </p> 427 </td> 428<td> 429 <p> 430 <span class="inlinemediaobject"><img src="../../../../img/nyi.png" alt="nyi"></span> 431 </p> 432 </td> 433</tr> 434<tr> 435<td> 436 <p> 437 MultiPolygon 438 </p> 439 </td> 440<td> 441 <p> 442 <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span> 443 </p> 444 </td> 445<td> 446 <p> 447 <span class="inlinemediaobject"><img src="../../../../img/nyi.png" alt="nyi"></span> 448 </p> 449 </td> 450</tr> 451</tbody> 452</table></div> 453<h6> 454<a name="geometry.reference.algorithms.centroid.return_centroid_1.h8"></a> 455 <span class="phrase"><a name="geometry.reference.algorithms.centroid.return_centroid_1.complexity"></a></span><a class="link" href="return_centroid_1.html#geometry.reference.algorithms.centroid.return_centroid_1.complexity">Complexity</a> 456 </h6> 457<p> 458 Linear 459 </p> 460</div> 461<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 462<td align="left"></td> 463<td align="right"><div class="copyright-footer">Copyright © 2009-2019 Barend Gehrels, Bruno Lalande, Mateusz Loskot, Adam 464 Wulkiewicz, Oracle and/or its affiliates<p> 465 Distributed under the Boost Software License, Version 1.0. (See accompanying 466 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>) 467 </p> 468</div></td> 469</tr></table> 470<hr> 471<div class="spirit-nav"> 472<a accesskey="p" href="centroid_2.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../centroid.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="return_centroid_2_with_strategy.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 473</div> 474</body> 475</html> 476
