计算多边形kml的质心[关闭]答案

【问题标题】：calculate centorid of the polygon kml [closed]计算多边形kml的质心[关闭]
【发布时间】：2018-06-01 03:06:10
【问题描述】：

点分布不均匀时如何计算多边形的中心？在下面的kml 文件中，lat/lons 的 30% 位于一侧，因此平均值不会产生好的结果。有没有人知道任何好的库来实现它？

<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2" 
xmlns:gx="http://www.google.com/kml/ext/2.2" 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://www.opengis.net/kml/2.2 
http://schemas.opengis.net/kml/2.2.0/ogckml22.xsd 
http://www.google.com/kml/ext/2.2 
http://code.google.com/apis/kml/schema/kml22gx.xsd">
  <Document id="DLS_Parcels">
    <name>DLS_Parcels</name>
   <Snippet/>
<Folder id="FeatureLayer0">
  <name>DLS_Parcels</name>
  <Snippet/>
  <Placemark id="ID_00000">
    <name>189</name>
    <Snippet/>
    <description><![CDATA[<html><body><table border="1"><tr><th>Field Name</th><th>Field Value</th></tr><tr><td>OBJECTID</td><td>240106</td></tr><tr><td>SBPI_ID_NO</td><td>1076078</td></tr><tr><td>District Code</td><td>6</td></tr><tr><td>Municipality/Community Code</td><td>343</td></tr><tr><td>Quarter Code</td><td>1</td></tr><tr><td>Block Code</td><td>0</td></tr><tr><td>Parcel Number</td><td>189</td></tr><tr><td>Sheet</td><td>26</td></tr><tr><td>Plan</td><td>50</td></tr><tr><td>SRC_SL_CODE</td><td>5</td></tr><tr><td>SOURCE</td><td>DCDB</td></tr><tr><td>Parcel Area</td><td>2516</td></tr><tr><td>CadastralPlan</td><td>Null</td></tr></table></body></html>]]></description>
    <styleUrl>#PolyStyle00</styleUrl>
    <MultiGeometry>
      <Polygon>
        <extrude>0</extrude>
        <altitudeMode>clampToGround</altitudeMode>
        <tessellate>1</tessellate>
        <outerBoundaryIs>
          <LinearRing>
            <coordinates> 32.394743,35.040539,0.000000 
32.394946,35.040474,0.000000 32.395228,35.040376,0.000000 
32.395274,35.040366,0.000000 32.395306,35.040379,0.000000 
32.395318,35.040406,0.000000 32.395308,35.040847,0.000000 
32.394855,35.040830,0.000000 32.394861,35.040659,0.000000 
32.394642,35.040669,0.000000 32.394506,35.040674,0.000000 
32.394505,35.040673,0.000000 32.394505,35.040672,0.000000 
32.394505,35.040671,0.000000 32.394504,35.040670,0.000000 
32.394504,35.040669,0.000000 32.394504,35.040668,0.000000 
32.394503,35.040667,0.000000 32.394503,35.040666,0.000000 
32.394503,35.040666,0.000000 32.394503,35.040665,0.000000 
32.394502,35.040664,0.000000 32.394502,35.040663,0.000000 
32.394502,35.040662,0.000000 32.394502,35.040661,0.000000 
32.394502,35.040660,0.000000 32.394502,35.040659,0.000000 
32.394501,35.040658,0.000000 32.394501,35.040657,0.000000 
32.394501,35.040656,0.000000 32.394501,35.040655,0.000000 
32.394501,35.040654,0.000000 32.394501,35.040653,0.000000 
32.394501,35.040652,0.000000 32.394501,35.040651,0.000000 
32.394501,35.040650,0.000000 32.394501,35.040649,0.000000 
32.394502,35.040649,0.000000 32.394502,35.040648,0.000000 
32.394502,35.040647,0.000000 32.394502,35.040646,0.000000 
32.394502,35.040645,0.000000 32.394502,35.040644,0.000000 
32.394503,35.040643,0.000000 32.394503,35.040642,0.000000 
32.394503,35.040641,0.000000 32.394503,35.040640,0.000000 
32.394504,35.040639,0.000000 32.394504,35.040638,0.000000 
32.394504,35.040637,0.000000 32.394505,35.040636,0.000000 
32.394505,35.040636,0.000000 32.394505,35.040635,0.000000 
32.394506,35.040634,0.000000 32.394506,35.040633,0.000000 
32.394507,35.040632,0.000000 32.394507,35.040631,0.000000 
32.394508,35.040630,0.000000 32.394508,35.040629,0.000000 
32.394509,35.040629,0.000000 32.394509,35.040628,0.000000 
32.394510,35.040627,0.000000 32.394510,35.040626,0.000000 
32.394511,35.040625,0.000000 32.394512,35.040624,0.000000 
32.394512,35.040624,0.000000 32.394513,35.040623,0.000000 
32.394514,35.040622,0.000000 32.394514,35.040621,0.000000 
32.394515,35.040621,0.000000 32.394516,35.040620,0.000000 
32.394516,35.040619,0.000000 32.394517,35.040618,0.000000 
32.394518,35.040618,0.000000 32.394519,35.040617,0.000000 
32.394519,35.040616,0.000000 32.394520,35.040616,0.000000 
32.394521,35.040615,0.000000 32.394522,35.040614,0.000000 
32.394523,35.040614,0.000000 32.394524,35.040613,0.000000 
32.394624,35.040579,0.000000 32.394743,35.040539,0.000000</coordinates>
            </LinearRing>
        </outerBoundaryIs>
      </Polygon>
    </MultiGeometry>
  </Placemark>
</Folder>
<Style id="PolyStyle00">
  <LabelStyle>
    <color>00000000</color>
    <scale>0.000000</scale>
  </LabelStyle>
  <LineStyle>
    <color>ff0000e6</color>
    <width>3.000000</width>
  </LineStyle>
  <PolyStyle>
    <color>00000000</color>
    <outline>1</outline>
  </PolyStyle>
</Style>
</Document>
</kml>

【问题讨论】：

标签： geometry polygon kml computational-geometry

【解决方案1】：

您可以使用geoPHP

这是一个例子

$kml = '<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://www.opengis.net/kml/2.2">
  <Placemark>
    <name>The Pentagon</name>
    <Polygon>
      <extrude>1</extrude>
      <altitudeMode>relativeToGround</altitudeMode>
      <outerBoundaryIs>
        <LinearRing>
          <coordinates>
            -77.05788457660967,38.87253259892824,100 
            -77.05465973756702,38.87291016281703,100 
            -77.05315536854791,38.87053267794386,100 
            -77.05552622493516,38.868757801256,100 
            -77.05844056290393,38.86996206506943,100 
            -77.05788457660967,38.87253259892824,100
          </coordinates>
        </LinearRing>
      </outerBoundaryIs>
      <innerBoundaryIs>
        <LinearRing>
          <coordinates>
            -77.05668055019126,38.87154239798456,100 
            -77.05542625960818,38.87167890344077,100 
            -77.05485125901024,38.87076535397792,100 
            -77.05577677433152,38.87008686581446,100 
            -77.05691162017543,38.87054446963351,100 
            -77.05668055019126,38.87154239798456,100
          </coordinates>
        </LinearRing>
      </innerBoundaryIs>
    </Polygon>
  </Placemark>
</kml>';

$polygon = geoPHP::load($kml, 'kml');

$centroid = $polygon->getCentroid();

$centX = $centroid->getX();

$centY = $centroid->getY();

【讨论】：