Unanswered Questions

34,110 questions with no upvoted or accepted answers
32 votes
0 answers
3k views

Leaflet v1 plugin: layer control for ungrouped, grouped, and nested-grouped layers

I need a Leaflet plugin which extends L.Control.Layers. I have the following requirements: works with Leaflet 1.x handles ungrouped layers alongside grouped ones handles nested layer groups does not ...
17 votes
0 answers
2k views

Extract TopoJSON directly from PostGIS

I have a simple "region" table: id (TEXT), name (TEXT), geom (MULTIPOLYGON). Here's the query I can use to extract a GeoJSON FeatureCollection: SELECT row_to_json(fc) FROM ( SELECT '...
16 votes
1 answer
1k views

Constructing a Voronoi diagram using a complicated travel time metric

I have in my possession four sets of shapefiles: 1. Locations (points), around 1000 2. Roads (lines), each road has a speed attribute 3. Terrain (polygons), each zone also has a speed attribute 4. ...
14 votes
1 answer
588 views

Remove reference to raster layer object PyQGIS

I am developing a plugin to load a set of raster files on QGIS. When there is a large number of files to be loaded, the main UI freezes. So I use QgsTask to move the creation of raster layers to a ...
14 votes
0 answers
688 views

High PostgreSQL/PostGIS memory and disk usage when saving QGIS project

Why would simply pressing the Save button in QGIS cause my local PostgreSQL instance to cause memory and disk usage to spike to "Not Responding" levels? Seems to me like the PostgreSQL ...
12 votes
0 answers
2k views

Making polygon for every point in set using Voronoi diagram

I'm trying to make polygons from points, where each point will be represented by one polygon. I tried using Voronois, but the results are incomplete. While I more or less understand where this ...
12 votes
0 answers
293 views

Processing post-execution script hook to clear scratch layers?

I've been cobbling together some Processing scripts for QGIS 2.18 (I'm not a fan of QGIS 3 scripts), and I keep running into one particular problem: my script creates a lot of scratch layers and they ...
11 votes
0 answers
499 views

Calculate volume of space defined by multiple overlapping 3D polygons

I have thousands of 3D polygons scattered in space but they mostly overlap with many of their neighbors in big extent. Is there any way how to compute volume they define effectively? I would love ...
11 votes
0 answers
392 views

Multithreaded DB connection for QGIS plugin

I am using QGIS 2.18.21 and PostgreSQL 9.6. on a Windows 8 machine. I am trying to do processing of a certain database task in the background, and I want the user to be able to continue to work in ...
11 votes
0 answers
312 views

ESRI Runtime Geodatabase Shape storage

Does anyone out there know the geometry storage encoding for ESRI's Runtime Geodatabase (.sqlite) format? aka mobile geodatabase. There are 'GDB_ tables', 'st_ tables', 'RTREE indexes' and other ...
11 votes
0 answers
518 views

MapScript with Python 3

I am trying to build raster summarizing features into a GeoDjango webmap, and would like to use the django-raster and django-wms packages to do so. I believe that I have them set up correctly, but am ...
10 votes
0 answers
275 views

Saving ArcGIS Pro symbology to PostGIS DB for each layer

I want to have a default style/symbology assigned to each layer in a PostGIS database so that whenever it is loaded in ArcGIS Pro, it will come up with the default style. There is a way in QGIS to ...
10 votes
0 answers
675 views

PyQgis Exporting Print Layout: "ERROR 6: The PNG driver does not support update access to existing datasets."

I am trying to export a .tif loaded into a pre-configured print layout template and further exported as .png def openLayer(project, fp, basename, vector=True): layer = QgsVectorLayer(fp, basename) ...
10 votes
0 answers
410 views

PyQGIS script crashes QGIS 3 when removing a custom pluginLayer which has custom legend

I upgrade a 2.18 plugin to 3.4. PluginLayer has been refactored and I could not create a custom legend as simple as previous major version of QGIS 2 : QgsDefaultPluginLayerLegend was removed. Use ...
10 votes
1 answer
540 views

Removing overlapping features by percentage in PostGIS

I have geometry records of type MultiLineStringZM and I am trying to INSERT new records that overlap some of the records currently in the table. If they were type MultiPolygon I could use ST_Area() as ...

15 30 50 per page
1
2 3 4 5
2274