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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I have seen examples where for the purpose of overlay operations, someone chops up their large polys into smaller ones, each with an attribute that contains
the id for the large poly. I don’t know if that would fit your use case.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">David.<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> mapserver-users [mailto:mapserver-users-bounces@lists.osgeo.org]
<b>On Behalf Of </b>Ben Madin<br>
<b>Sent:</b> Friday, October 23, 2015 1:23 AM<br>
<b>To:</b> Lydon Chandra<br>
<b>Cc:</b> mapserver-users@lists.osgeo.org<br>
<b>Subject:</b> Re: [mapserver-users] Shapefile spatial index challenge<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">G’day Lydon,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I feel your pain, but there is little benefit to creating more quadrants. The idea (as I understand it - could be wrong) is to be able to use a (fast) bounding box to find the polygons to test, rather than having to test against every polygon
using more complex algorithms. <o:p></o:p></p>
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<p class="MsoNormal">I suppose you could consider that if you want to find out if a point is in one or more of your polygons, the benefit of having more index squares. You only have 8 polygons (I presume) so this should limit you in most cases to only having
to compare your ‘point’ with only a couple of polygons using the more complex algorithms.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">hth<o:p></o:p></p>
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<p class="MsoNormal">cheers<o:p></o:p></p>
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<p class="MsoNormal">Ben<o:p></o:p></p>
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<p class="MsoNormal">On 2015-10-08, at 21:31 , Lydon Chandra <<a href="mailto:lydon_chandra@technologyonecorp.com">lydon_chandra@technologyonecorp.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Hi List,<o:p></o:p></p>
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<p class="MsoNormal">How can we generate more quadrants for the spatial index for the Australia polygon below ?<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Using MapServer shptree, even forcing it to go to 50 level deep, the spatial index does not have more quadrants.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">More data and details at:<o:p></o:p></p>
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<p class="MsoNormal"><a href="http://www.evernote.com/l/AhrYASBGtqVOkJn0BLqZkceADvOsA_UBfvY/" target="_blank">http://www.evernote.com/l/AhrYASBGtqVOkJn0BLqZkceADvOsA_UBfvY/</a><o:p></o:p></p>
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<p class="MsoNormal"><image.png><o:p></o:p></p>
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<p class="MsoNormal">Kind Regards,<o:p></o:p></p>
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<p class="MsoNormal">Don<br clear="all">
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<p class="MsoNormal">_______________________________________________<br>
mapserver-users mailing list<br>
<a href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/mapserver-users">http://lists.osgeo.org/mailman/listinfo/mapserver-users</a><o:p></o:p></p>
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<p class="MsoNormal"><span style="font-family:"Helvetica","sans-serif";color:black"><br>
-- <br>
<br>
Ben Madin<br>
<br>
t : +61 8 6102 5535<br>
m : +61 448 887 220<br>
e : <a href="mailto:ben@ausvet.com.au">ben@ausvet.com.au</a><br>
<br>
AusVet Animal Health Services<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Helvetica","sans-serif";color:black"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Helvetica","sans-serif";color:black">18/27 Market Street, Fremantle<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-family:"Helvetica","sans-serif";color:black">Western Australia<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-family:"Helvetica","sans-serif";color:black">AusVet's website: <a href="http://www.ausvet.com.au">http://www.ausvet.com.au</a> Find our office: <a href="http://w3w.co/leader.code.frozen">http://w3w.co/leader.code.frozen</a><br>
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This transmission is for the intended addressee only and is confidential information. If you have received this transmission in error, please delete it and notify the sender. The contents of this email are the opinion of the writer only and are not endorsed
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