libs/geometry/doc/html/geometry/reference/algorithms/is_valid/is_valid_1.html

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  25 <div class="section">
  26 <div class="titlepage"><div><div><h5 class="title">
  27 <a name="geometry.reference.algorithms.is_valid.is_valid_1"></a><a class="link" href="is_valid_1.html" title="is_valid">is_valid</a>
  28 </h5></div></div></div>
  29 <p>
  30             <a class="indexterm" name="idp99868496"></a>
  31 Checks if a geometry is valid (in the OGC sense)
  32           </p>
  33 <h6>
  34 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h0"></a>
  35             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.synopsis"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.synopsis">Synopsis</a>
  36           </h6>
  37 <p>
  38 </p>
  39 <pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Geometry</span><span class="special">&gt;</span>
  40 <span class="keyword">bool</span> <span class="identifier">is_valid</span><span class="special">(</span><span class="identifier">Geometry</span> <span class="keyword">const</span> <span class="special">&amp;</span> <span class="identifier">geometry</span><span class="special">)</span></pre>
  41 <p>
  42           </p>
  43 <h6>
  44 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h1"></a>
  45             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.parameters"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.parameters">Parameters</a>
  46           </h6>
  47 <div class="informaltable"><table class="table">
  48 <colgroup>
  49 <col>
  50 <col>
  51 <col>
  52 <col>
  53 </colgroup>
  54 <thead><tr>
  55 <th>
  56                     <p>
  57                       Type
  58                     </p>
  59                   </th>
  60 <th>
  61                     <p>
  62                       Concept
  63                     </p>
  64                   </th>
  65 <th>
  66                     <p>
  67                       Name
  68                     </p>
  69                   </th>
  70 <th>
  71                     <p>
  72                       Description
  73                     </p>
  74                   </th>
  75 </tr></thead>
  76 <tbody><tr>
  77 <td>
  78                     <p>
  79                       Geometry const &amp;
  80                     </p>
  81                   </td>
  82 <td>
  83                     <p>
  84                       Any type fulfilling a Geometry Concept
  85                     </p>
  86                   </td>
  87 <td>
  88                     <p>
  89                       geometry
  90                     </p>
  91                   </td>
  92 <td>
  93                     <p>
  94                       A model of the specified concept
  95                     </p>
  96                   </td>
  97 </tr></tbody>
  98 </table></div>
  99 <h6>
 100 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h2"></a>
 101             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.returns"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.returns">Returns</a>
 102           </h6>
 103 <p>
 104             Returns true if the geometry is valid (in the OGC sense); furthermore,
 105             the following geometries are considered valid: multi-geometries with
 106             no elements, linear geometries containing spikes, areal geometries with
 107             duplicate (consecutive) points
 108           </p>
 109 <h6>
 110 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h3"></a>
 111             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.header"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.header">Header</a>
 112           </h6>
 113 <p>
 114             Either
 115           </p>
 116 <p>
 117             <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span></code>
 118           </p>
 119 <p>
 120             Or
 121           </p>
 122 <p>
 123             <code class="computeroutput"><span class="preprocessor">#include</span> <span class="special">&lt;</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">is_valid</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
 124           </p>
 125 <h6>
 126 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h4"></a>
 127             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.conformance"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.conformance">Conformance</a>
 128           </h6>
 129 <p>
 130             The function is_valid is not defined by OGC.
 131           </p>
 132 <h6>
 133 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h5"></a>
 134             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.supported_geometries"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.supported_geometries">Supported
 135             geometries</a>
 136           </h6>
 137 <div class="informaltable"><table class="table">
 138 <colgroup>
 139 <col>
 140 <col>
 141 </colgroup>
 142 <thead><tr>
 143 <th>
 144                     <p>
 145                       Geometry
 146                     </p>
 147                   </th>
 148 <th>
 149                     <p>
 150                       Status
 151                     </p>
 152                   </th>
 153 </tr></thead>
 154 <tbody>
 155 <tr>
 156 <td>
 157                     <p>
 158                       Point
 159                     </p>
 160                   </td>
 161 <td>
 162                     <p>
 163                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 164                     </p>
 165                   </td>
 166 </tr>
 167 <tr>
 168 <td>
 169                     <p>
 170                       Segment
 171                     </p>
 172                   </td>
 173 <td>
 174                     <p>
 175                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 176                     </p>
 177                   </td>
 178 </tr>
 179 <tr>
 180 <td>
 181                     <p>
 182                       Box
 183                     </p>
 184                   </td>
 185 <td>
 186                     <p>
 187                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 188                     </p>
 189                   </td>
 190 </tr>
 191 <tr>
 192 <td>
 193                     <p>
 194                       Linestring
 195                     </p>
 196                   </td>
 197 <td>
 198                     <p>
 199                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 200                     </p>
 201                   </td>
 202 </tr>
 203 <tr>
 204 <td>
 205                     <p>
 206                       Ring
 207                     </p>
 208                   </td>
 209 <td>
 210                     <p>
 211                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 212                     </p>
 213                   </td>
 214 </tr>
 215 <tr>
 216 <td>
 217                     <p>
 218                       Polygon
 219                     </p>
 220                   </td>
 221 <td>
 222                     <p>
 223                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 224                     </p>
 225                   </td>
 226 </tr>
 227 <tr>
 228 <td>
 229                     <p>
 230                       MultiPoint
 231                     </p>
 232                   </td>
 233 <td>
 234                     <p>
 235                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 236                     </p>
 237                   </td>
 238 </tr>
 239 <tr>
 240 <td>
 241                     <p>
 242                       MultiLinestring
 243                     </p>
 244                   </td>
 245 <td>
 246                     <p>
 247                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 248                     </p>
 249                   </td>
 250 </tr>
 251 <tr>
 252 <td>
 253                     <p>
 254                       MultiPolygon
 255                     </p>
 256                   </td>
 257 <td>
 258                     <p>
 259                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 260                     </p>
 261                   </td>
 262 </tr>
 263 <tr>
 264 <td>
 265                     <p>
 266                       Variant
 267                     </p>
 268                   </td>
 269 <td>
 270                     <p>
 271                       <span class="inlinemediaobject"><img src="../../../../img/ok.png" alt="ok"></span>
 272                     </p>
 273                   </td>
 274 </tr>
 275 </tbody>
 276 </table></div>
 277 <h6>
 278 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h6"></a>
 279             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.complexity"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.complexity">Complexity</a>
 280           </h6>
 281 <p>
 282             Constant-time for points, segments, boxes and multi-points
 283           </p>
 284 <p>
 285             Linear for linestrings and multi-linestrings
 286           </p>
 287 <p>
 288             Linearithmic for rings
 289           </p>
 290 <p>
 291             Currently, worst-case quadratic for polygons and multi-polygons
 292           </p>
 293 <h6>
 294 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h7"></a>
 295             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.example"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.example">Example</a>
 296           </h6>
 297 <p>
 298             Checks whether a geometry is valid
 299           </p>
 300 <p>
 301 </p>
 302 <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>
 303
 304 <span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span>
 305 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">point_xy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 306 <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">geometry</span><span class="special">/</span><span class="identifier">geometries</span><span class="special">/</span><span class="identifier">polygon</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
 307
 308
 309 <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
 310 <span class="special">{</span>
 311     <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">d2</span><span class="special">::</span><span class="identifier">point_xy</span><span class="special">&lt;</span><span class="keyword">double</span><span class="special">&gt;</span> <span class="identifier">point_type</span><span class="special">;</span>
 312     <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">model</span><span class="special">::</span><span class="identifier">polygon</span><span class="special">&lt;</span><span class="identifier">point_type</span><span class="special">&gt;</span> <span class="identifier">polygon_type</span><span class="special">;</span>
 313
 314     <span class="identifier">polygon_type</span> <span class="identifier">poly</span><span class="special">;</span>
 315     <span class="identifier">boost</span><span class="special">::</span><span class="identifier">geometry</span><span class="special">::</span><span class="identifier">read_wkt</span><span class="special">(</span><span class="string">"POLYGON((0 0,0 10,10 10,10 0,0 0),(0 0,9 1,9 2,0 0),(0 0,2 9,1 9,0 0),(2 9,9 2,9 9,2 9))"</span><span class="special">,</span> <span class="identifier">poly</span><span class="special">);</span>
 316
 317     <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"is valid? "</span> <span class="special">&lt;&lt;</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">is_valid</span><span class="special">(</span><span class="identifier">poly</span><span class="special">)</span> <span class="special">?</span> <span class="string">"yes"</span> <span class="special">:</span> <span class="string">"no"</span><span class="special">)</span> <span class="special">&lt;&lt;</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span>
 318
 319     <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
 320 <span class="special">}</span>
 321 </pre>
 322 <p>
 323           </p>
 324 <p>
 325             Output:
 326           </p>
 327 <pre class="programlisting">is valid? no
 328
 329 <img src="../../../../img/algorithms/is_valid_example.png" alt="is_valid_example">
 330
 331 </pre>
 332 <h6>
 333 <a name="geometry.reference.algorithms.is_valid.is_valid_1.h8"></a>
 334             <span class="phrase"><a name="geometry.reference.algorithms.is_valid.is_valid_1.see_also"></a></span><a class="link" href="is_valid_1.html#geometry.reference.algorithms.is_valid.is_valid_1.see_also">See
 335             also</a>
 336           </h6>
 337 <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem">
 338                 <a class="link" href="../is_simple.html" title="is_simple">is_simple</a>
 339               </li></ul></div>
 340 </div>
 341 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 342 <td align="left"></td>
 343 <td align="right"><div class="copyright-footer">Copyright &#169; 2009-2017 Barend
 344       Gehrels, Bruno Lalande, Mateusz Loskot, Adam Wulkiewicz, Oracle and/or its
 345       affiliates<p>
 346         Distributed under the Boost Software License, Version 1.0. (See accompanying
 347         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>)
 348       </p>
 349 </div></td>
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