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<title>GEOS: geos::algorithm::CentroidArea Class Reference</title>
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<h1>geos::algorithm::CentroidArea Class Reference</h1> </div>
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<!-- doxytag: class="geos::algorithm::CentroidArea" -->
<p>Computes the centroid of an area geometry.
<a href="#_details">More...</a></p>
<p><code>#include <<a class="el" href="geosAlgorithm_8h_source.html">geos/geosAlgorithm.h</a>></code></p>
<p><a href="classgeos_1_1algorithm_1_1CentroidArea-members.html">List of all members.</a></p>
<table class="memberdecls">
<tr><td colspan="2"><h2><a name="pub-methods"></a>
Public Member Functions</h2></td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1algorithm_1_1CentroidArea.html#a3453f5cd603fdbf9680b90bbe918f216">add</a> (const <a class="el" href="classgeos_1_1geom_1_1Geometry.html">geom::Geometry</a> *geom)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1algorithm_1_1CentroidArea.html#a57305fbb2a2bb84e2e5bd790c028a98a">add</a> (const <a class="el" href="classgeos_1_1geom_1_1CoordinateSequence.html">geom::CoordinateSequence</a> *ring)</td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a5bf54b5d65fe560663bee230c42222b6"></a><!-- doxytag: member="geos::algorithm::CentroidArea::getCentroid" ref="a5bf54b5d65fe560663bee230c42222b6" args="() const " -->
<a class="el" href="classgeos_1_1geom_1_1Coordinate.html">geom::Coordinate</a> * </td><td class="memItemRight" valign="bottom"><b>getCentroid</b> () const </td></tr>
<tr><td class="memItemLeft" align="right" valign="top"><a class="anchor" id="a04d4c6d5fd06fec2fe9cb95749ad0aa7"></a><!-- doxytag: member="geos::algorithm::CentroidArea::getCentroid" ref="a04d4c6d5fd06fec2fe9cb95749ad0aa7" args="(geom::Coordinate &ret) const " -->
bool </td><td class="memItemRight" valign="bottom"><a class="el" href="classgeos_1_1algorithm_1_1CentroidArea.html#a04d4c6d5fd06fec2fe9cb95749ad0aa7">getCentroid</a> (<a class="el" href="classgeos_1_1geom_1_1Coordinate.html">geom::Coordinate</a> &ret) const </td></tr>
<tr><td class="mdescLeft"> </td><td class="mdescRight">Return false if a centroid couldn't be computed. <br/></td></tr>
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<hr/><a name="_details"></a><h2>Detailed Description</h2>
<p>Computes the centroid of an area geometry. </p>
<p>Algorithm:</p>
<p>Based on the usual algorithm for calculating the centroid as a weighted sum of the centroids of a decomposition of the area into (possibly overlapping) triangles. The algorithm has been extended to handle holes and multi-polygons. See <code><a href="http://www.faqs.org/faqs/graphics/algorithms-faq/">http://www.faqs.org/faqs/graphics/algorithms-faq/</a></code> for further details of the basic approach. </p>
<hr/><h2>Member Function Documentation</h2>
<a class="anchor" id="a3453f5cd603fdbf9680b90bbe918f216"></a><!-- doxytag: member="geos::algorithm::CentroidArea::add" ref="a3453f5cd603fdbf9680b90bbe918f216" args="(const geom::Geometry *geom)" -->
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<td class="memname">void geos::algorithm::CentroidArea::add </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="classgeos_1_1geom_1_1Geometry.html">geom::Geometry</a> * </td>
<td class="paramname"> <em>geom</em></td>
<td> ) </td>
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<p>Adds the area defined by a Geometry to the centroid total. If the geometry has no area it does not contribute to the centroid.</p>
<dl><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>geom</em> </td><td>the geometry to add </td></tr>
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<a class="anchor" id="a57305fbb2a2bb84e2e5bd790c028a98a"></a><!-- doxytag: member="geos::algorithm::CentroidArea::add" ref="a57305fbb2a2bb84e2e5bd790c028a98a" args="(const geom::CoordinateSequence *ring)" -->
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<td class="memname">void geos::algorithm::CentroidArea::add </td>
<td>(</td>
<td class="paramtype">const <a class="el" href="classgeos_1_1geom_1_1CoordinateSequence.html">geom::CoordinateSequence</a> * </td>
<td class="paramname"> <em>ring</em></td>
<td> ) </td>
<td></td>
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<p>Adds the area defined by an array of coordinates. The array must be a ring; i.e. end with the same coordinate as it starts with. </p>
<dl><dt><b>Parameters:</b></dt><dd>
<table border="0" cellspacing="2" cellpadding="0">
<tr><td valign="top"></td><td valign="top"><em>ring</em> </td><td>an array of <a class="el" href="">Coordinate</a>s </td></tr>
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</dd>
</dl>
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<hr/>The documentation for this class was generated from the following file:<ul>
<li><a class="el" href="CentroidArea_8h_source.html">CentroidArea.h</a></li>
</ul>
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