4
votes
Accepted
Converting pipe-separated file containing GeoJSON geometries to GeoJSON with ogr2ogr
As geom is not the default name, you need to add -oo GEOM_POSSIBLE_NAMES=geom to tell ogr2ogr that the geometry is in the geom column: CSV driver: open options.
Something like this:
ogr2ogr -f "...
- 3,804
3
votes
Accepted
More efficient way to use Symmetrical Difference tool for layer with many features
A typical way to solve this is to reduce the size and complexity of the input geometries by first doing an intersection of them with a grid-layer. This can give an enormous difference in processing ...
- 3,804
3
votes
Dealing with NULL when using aggregate function in QGIS Expression
You can replace NULL with empty geometry, e.g.
geom_to_wkt(union(make_point(1, 4), if(is_empty_or_null(make_point(1,2)), geom_from_wkt('POINT()'), make_point(1,2))))
--> 'MultiPoint ((1 4),(1 2))'
...
- 8,838
2
votes
Dealing with NULL when using aggregate function in QGIS Expression
One way is to use array_remove_all to actually remove all NULL values from an array before using collect_geometries:
geom_to_wkt(
collect_geometries(
array_remove_all(
array(...
- 10.7k
2
votes
QGIS - collect geometries with geometrygenerator by value to display only one label
If your road are polygon feature you may use the expression :
buffer (collect ($geometry,"name" ),0)
in the geometry generator to get one polygon for feature with the same name
- 16.9k
1
vote
More efficient way to use Symmetrical Difference tool for layer with many features
Having large complex geometries will slow down processing.
Try:
Multipart To Singleparts
Subdivide
3. And Create Spatial Index
On both input layers
- 76.3k
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