47
votes
Filter by bounding box in GeoPandas
You can use the cx method on a geodataframe to select rows within a bounding box. For your example frames:
xmin, ymin, xmax, ymax = df_sussex.total_bounds
sac_sussex = df_sac.cx[xmin:xmax, ymin:ymax]
...
- 894
29
votes
Accepted
Refering to another layer with Field Calculator in QGIS
For QGIS versions QGIS 3.16 and higher
Since QGIS 3.16 the functionality of the "refFunctions plugin" was emended into core. The current corresponding function is the overlay_within().
For ...
- 1,946
27
votes
Displaying overlapping points in QGIS
Try renderers: "Point displacement" or "Point Cluster" from symbology menu. (QGIS 3.x required for point cluster.)
As point displacement they can look like this for example:
And ...
- 32.6k
26
votes
Accepted
Check whether table has overlapping polygons, in PostGIS?
In the situation where you only need to know whether a table contains any overlapping polygons, and you're not concerned with the size or abundance of overlaps, I recommend a query of the following ...
- 12.9k
23
votes
Accepted
Using ST_Difference to remove overlapping features?
A self-join allows you to operate on the relationship between pairs of two features. But I don't think you're interested in pairs: for each feature, you want to operate on the relationship between ...
- 12.9k
21
votes
Refering to another layer with Field Calculator in QGIS
It can be done in Field Calculator with function aggregate(). In point layer create new field with field calculator expression like this:
aggregate(
layer:= 'polygon_layer_name',
aggregate:='...
- 6,765
20
votes
Accepted
Merging overlapping features using Geopandas?
The GeoDataFrame
import geopandas as gpd
g1 = gpd.GeoDataFrame.from_file("poly_intersect.shp")
g1.shape
(4, 3)
1) You can use the itertools module
a) If you want to merge the intersections of the ...
- 54.2k
20
votes
Counting points in polygons using QGIS
The tool you're looking for is now called "Count points in polygons", and it can be found in the QGIS's Processing Toolbox (Ctrl+Alt+T) under Vector analysis tools or can be also launched ...
- 8,546
19
votes
Calculating percent area of intersection in WHERE clause
Adding to Alexandre's very useful answer, if some of your census units may span three of your towns (and therefore you can't guarantee more than 50% falls in any town) you can do this:
select ...
- 321
16
votes
Summing up values of overlapping polygons in QGIS
QGIS 3.2
Thanks to new Union tool in QGIS 3.2, this has become quite easy!!!
What we do, is just use Union and Aggregate tools.
(1) Union (Processing Toolbox | Vetor Overlay | Union)
(2) We ...
- 30.4k
15
votes
Accepted
Identifying polygons that intersect with another layer using QGIS
There is a possibility using a "Virtual Layer" through Layer > Add Layer > Add/Edit Virtual Layer...
Let's assume we have three features in 'vegetation' (green) and four in 'treatment' ...
- 29.9k
14
votes
Accepted
Removing overlaps and keeping highest priority polygon using PostGIS
Fortunately, with the prio dependency, this is easier to solve than a purely recursive difference aggregation.
I'd prefer the LATERAL statement (here in full verbose mode), both for clarity of the ...
- 28.8k
14
votes
Accepted
Correcting the geometry of overlapping polygons in the same layer in QGIS
First make sure your Buildings have a unique "id" (which does not contain a | character, you will see why below). You can add it for example via field calculator by adding a new field with ...
- 32.6k
13
votes
Calculating percentage of overlap between two different layers using ArcMap
Add a new field to both layers to hold the original areas and call it Area
Calculate the areas for all the polygons in each layer and put into the Area field
Execute a union of layer 1 and layer 2 - ...
- 7,275
13
votes
Merging neighbouring polygons in QGIS
You can use the dissolve tool from the QGIS Processing Toolbox. You find it at Vector > Geoprocessing Tools > Dissolve (see documentation). This will give you a large polygon where all parts are ...
- 6,215
13
votes
Show more than 6 labels for the same point using QGIS
Use Geometry Generator for full control of no. of labels and their placement
By default, QGIS uses max. 8 different positions for label placement as established best practice in cartography is to have ...
- 63.1k
12
votes
Counting number of points per line in QGIS
You can use Join by location to join polyline with point shapefiles. However, the point should be exactly snapped to the line in order to be joined, otherwise, it is better to create a buffer of ...
- 40.3k
12
votes
Calculating percentage of overlap of two layers in QGIS 3
Since QGIS 3.8, it's now included in QGIS core, without plugin or coding.
In the Processing Toolbox, search for Overlap and open the Overlap analysis:
Source: http://changelog.qgis.org/en/qgis/...
- 7,050
12
votes
Accepted
One-to-many spatial join with results in one row in QGIS
There is a possibility of using a "Virtual Layer" through Layer > Add Layer > Add/Edit Virtual Layer...
Let's assume there are two polygon layers: 'Layer_A' (brown) and 'Layer_B' (...
- 29.9k
12
votes
Joining attributes by the biggest overlapping areas in QGIS
Since QGIS 3.12 (see the Changelog for more details) the "Join Attributes by Location" algorithm from the Processing Toolbox (Ctrl+Alt+T) has a switch to do exactly this:
The type of the ...
- 27.3k
12
votes
Accepted
Getting attribute information of multiple polygon intersected by line using QGIS
Try this expression:
array_to_string(overlay_intersects('Layer_A', name))
(assuming the City names are stored in name field in the 'Layer A').
- 30.4k
12
votes
Dissolving polygons contained within the same larger polygon in QGIS
If you want to dissolve in-place:
Start edit mode for the layer.
Select the bounding and interior polygons
Click "Merge selected features" button () in the Advanced digitizing Toolbar.
...
- 74.7k
11
votes
Can labels for overlapping points be combined/merged into one label?
One way of doing this is cloning the layer, using definition queries and labelling them separately, using upper-left only label position for the first layer and lower-left for second.
Add THEFIELD ...
- 22.6k
11
votes
Accepted
Removing overlapping part of polygons using QGIS?
You can use the 'Check Geometries' plugin (Vector/Geometry Tools/Check Geometries) to remove overlapping areas.
- 1,825
11
votes
Calculating proportional area of polygon within another layer's polygon using QGIS
Take your model layer and in the attribute table, add a new field called area_mod for example.
Note that there are two ways to generate area:
$area is an ellipsoid based calculation using not just ...
- 10.3k
11
votes
Accepted
Filter by bounding box in GeoPandas
Issue is because you are using 'total_bounds' method. It only produces a tuple with max and min points of bounding box. Method to be used is 'envelope'; previous to build its respective 'GeoDataFrame'....
- 29.4k
11
votes
Accepted
Looking for QGIS equivalent of ArcMap's "Selection by Location" tool with "Have their centroid in" option
There is no direct equivalent in Qgis core, but you can use the "Select Within" plugin, which should do exactly what you need (it adds an entry in the vector menu):
Otherwise, you would need to ...
- 831
11
votes
Accepted
Fitting known size polygons into irregular polygons using ArcGIS Desktop?
It is very complicated task known as bin packing problem.
The script below produces one of countless sub-optimal solutions. Algorithm:
places fish net over rotated POLYGON to find out rotation angle ...
- 22.6k
10
votes
Accepted
Dissolve overlapping polygons according to percent overlap using PostGIS?
This can be easily accomplished using PostGIS. Preview the results using a modified version of the query below:
SELECT a.id, b.id, ST_Area(a.shape), ST_Area(b.shape)
, 100*(ST_Area(...
- 1,136
10
votes
Accepted
Determining if two polygons are overlapping in Google Maps?
JSFiddle Example
I've created a JSFiddle demonstrating a solution to your problem using the JavaScript Topology Suite (JSTS) (JSTS) library.
Explaination
There are two steps to this approach. The ...
- 6,420
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