49
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]
...
- 924
29
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 ...
- 35.6k
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 ...
- 13.2k
22
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:='...
- 6,945
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 ...
- 8,718
17
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 ...
- 31.2k
16
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 ...
- 27.9k
15
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 ...
- 6,265
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' ...
- 34k
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 ...
- 30.9k
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 ...
- 35.6k
14
votes
Using rule-based symbology for overlapping layers in QGIS
Another solution would be to use a Geometry Generator fill for that, together with the powerful aggregate function:
aggregate(layer:='Buffered',
aggregate:='collect',
expression:=...
- 11.9k
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 ...
- 74.9k
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 ...
- 41.4k
12
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 ...
- 23.3k
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/...
- 7,447
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' (...
- 34k
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').
- 31.2k
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.
...
- 78k
12
votes
Deleting polygons within larger polygon in QGIS
Use Menu Vector / Geoprocessing Tools / Difference.
Blue Polygon minus yellow polygons = polygon outlined in red:
- 74.9k
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 ...
- 10.5k
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'....
- 30.2k
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
Getting only the intersection part of self-intersecting polygons in QGIS
You can create a virtual layer.
The query joins the layer to itself where two polygons intersect and their ids are different. And then calculates their intersection geometries.
You need an id column ...
- 77.7k
10
votes
Calculating percentage of overlap of two layers in QGIS 3
Using a "Virtual Layer" through Layer > Add Layer > Add/Edit Virtual Layer....
Let's assume there are two overlapping polygon layers called 'LayerA' (brown) and 'LayerB' (grey), see ...
- 34k
10
votes
Accepted
Best practice for counting polygons in polygons
True Polygon containment is a costly operation; not only does a containment check have to run intersection computations between each pair of vertices in one polygon for each pair of vertices in the ...
- 30.9k
10
votes
Accepted
Dissolving polygons that intersects in QGIS
You can dissolve without a dissolve field but Im not sure if that is what you want.
I suspect it is:
Dissolve
Multipart to singleparts
Field calculate @row_number
Intersect output with your original ...
- 77.7k
10
votes
Accepted
Calculating polygon area within other polygon using GeoPandas
Use GeoPandas Overlay
polygons = gpd.read_file("Polygons.shp")
small_polygon = gpd.read_file("Small_polygon.shp")
Intersection of the two GeoDataFrames:
result = gpd.overlay(...
- 55.4k
10
votes
Dissolving polygons contained within the same larger polygon in QGIS
To get as a different layer from the original one, use the following steps.
Select the polygons you want to dissolve
Run "Vector Geometry" -> "Dissolve tool". (Check "...
- 78k
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