Grass and postgis support topology, you can use qgis a front-end for them.<br><br>On Saturday, 7 March 2020, Stefan Keller <<a href="mailto:sfkeller@gmail.com">sfkeller@gmail.com</a>> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<br>
This is about processing either an area mesh (tesselation) layer. Area<br>
meshes are topological structures and issue is that most spatial data<br>
formats - other than TopoJSON and E00 - are non-topological.<br>
<br>
This in means, that a data reader has to infer the topology from<br>
geometry (which requires exponential computing time), and even worse,<br>
that potentially there are topological errors (like gaps,<br>
overlaps/slivers). The built-in "Topology Checker Plugin" of QGIS [1]<br>
does the validation preprocessing step.<br>
<br>
Are there any ideas to store topology in a polygon vector layer (e.g.<br>
as array of features IDs to reference polygon neighbors), so a reader<br>
(a PyQGIS function/extension) doesn't have to rebuild the topology<br>
every time?<br>
<br>
:Stefan<br>
<br>
[1] <a href="https://docs.qgis.org/3.4/en/docs/user_manual/plugins/core_plugins/plugins_topology_checker.html" target="_blank">https://docs.qgis.org/3.4/en/<wbr>docs/user_manual/plugins/core_<wbr>plugins/plugins_topology_<wbr>checker.html</a><br>
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