<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Hi<br/>
Thank you all for your quick answers.<br/>
Regards<br/>
Johannes</div>
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<div style="margin:0 0 10px 0;"><b>Gesendet:</b> Montag, 06. April 2020 um 12:51 Uhr<br/>
<b>Von:</b> "Bo Victor Thomsen" <bo.victor.thomsen@gmail.com><br/>
<b>An:</b> qgis-developer@lists.osgeo.org<br/>
<b>Betreff:</b> Re: [QGIS-Developer] Intersections with Qgis</div>
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<p> </p>
<p>Johannes -</p>
<p>The actual intersection code can contain a pre-check of bounding box intersection. This will probably decrease computation time significantly for the check:</p>
<p><tt>for i, geom_i in enumerate(geoms):</tt><br/>
<tt> for j, geom_j in enumerate(geoms):</tt><br/>
<tt> if j > i:</tt></p>
<p><tt> # Check bounding box first...<br/>
result = geom_i.boundingBoxIntersects(geom_j)<br/>
<br/>
if result:<br/>
<br/>
# Bounding box intersects, check actual geometry...<br/>
result = </tt><tt>geom_i.intersects(geom_j)<br/>
<br/>
# Do something with result...</tt></p>
<p> </p>
<pre class="moz-signature">--
Med venlig hilsen / Kind regards
Bo Victor Thomsen</pre>
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<p> </p>
<div class="moz-cite-prefix">Den 06-04-2020 kl. 11:36 skrev Johannes Wildermuth:</div>
<blockquote>
<div style="font-family: Verdana;font-size: 12.0px;">
<div>Hello developers<br/>
I've been currently working on a python plugin in which I have to find all possible intersections on one layer. I want to improve the efficiency of this task. It roughly looks like this:<br/>
for i, geom in enumerate(geoms):<br/>
for j, geom in enumerate(geoms):<br/>
if j > i:<br/>
//intersections<br/>
Is there a faster way? Perhaps with multithreading / rtree?<br/>
Regards<br/>
Johannes Wildermuth</div>
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