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<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'>Hi,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span style='font-size:10.0pt;
font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Can anybody explain how PostGIS calculates centroids?
I’ve checked the manual but the relevant section doesn’t refer to an
OGC Specification. From what I can understand, it takes an average of the
coordinates of all the vertices of an entry, ignoring whether or not the
centroid falls outside the polygons. Is this right? This differs from other
GIS- GeoMedia, for example, when confronted with a multipolygon entry, always
puts the centroid inside the largest polygon.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Can anybody shed some light on this?<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Cheers,<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=2 face=Arial><span lang=EN-GB style='font-size:
10.0pt;font-family:Arial'>Matt<o:p></o:p></span></font></p>
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face="Times New Roman"><span lang=EN-GB style='font-size:12.0pt'> <o:p></o:p></span></font></p>
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<p class=MsoNormal style='mso-element:frame'><font size=3 color="#2e3a75"
face=Arial><span lang=EN-GB style='font-size:12.0pt;font-family:Arial;
color:#2E3A75'>Matt Doughty</span></font><span lang=EN-GB><o:p></o:p></span></p>
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<p class=MsoNormal style='mso-element:frame'><font size=3 color="#2e3a75"
face=Arial><span style='font-size:12.0pt;font-family:Arial;color:#2E3A75'>GEOGRAMA
S.L.</span></font><font face=Arial><span style='font-family:Arial'><o:p></o:p></span></font></p>
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<p class=MsoNormal style='mso-element:frame'><font size=3 color="#2e3a75"
face=Arial><span style='font-size:12.0pt;font-family:Arial;color:#2E3A75'>Tel.:
+34 945 13 13 72 652 77 14 15</span></font><font
face=Arial><span style='font-family:Arial'><o:p></o:p></span></font></p>
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<p class=MsoNormal style='mso-element:frame'><font size=3 color="#2e3a75"
face=Arial><span style='font-size:12.0pt;font-family:Arial;color:#2E3A75'>Fax:
+34 945 23 03 40 </span></font><font face=Arial><span style='font-family:
Arial'><o:p></o:p></span></font></p>
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<p class=MsoNormal style='mso-element:frame'><font size=3 color="#2e3a75"
face=Arial><span style='font-size:12.0pt;font-family:Arial;color:#2E3A75'>www.geograma.com</span></font><font
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