41
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]
...
- 812
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 ...
- 1,876
26
votes
Removing overlapping/duplicate polygons in the same layer using QGIS
To remove duplicates:
You can use the Delete duplicate geometries tool by accessing it via the Processing Toolbox:
Another option is to use the v.clean tool from GRASS and select the rmdupl option:
...
- 72.5k
24
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 ...
- 12.4k
23
votes
Refering to another layer with Field Calculator in QGIS
Out of the box, field calculator does not support spatial joins across feature layers. But, if you have a look at NathanW's post on the function editor for qgis expressions you will be able to make ...
- 3,711
22
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 ...
- 12.4k
21
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 ...
- 26.2k
19
votes
Accepted
Identifying overlapping polygons in single layer using QGIS?
Enable Topology Checker Plugin in Plugin Manager. Add your polygonal layer in Topology Rule Settings window, select "must not overlap" rule and add them. To see overlap errors click on Validate button....
- 3,491
19
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:='...
- 6,487
19
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 ...
- 51.4k
18
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 ...
- 311
16
votes
Find overlapping polylines in same layer in ArcMap?
I recommend that you try using the Intersect (Analysis) tool with one input.
According to How Intersect works (with my bolding):
Intersect can run with a single input. In this case, instead of
...
- 63.9k
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 ...
- 29.2k
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 ...
- 24.5k
13
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 ...
- 26.2k
12
votes
Accepted
Select polygon features that intersect a line feature using pyqgis
areas = []
for line_feature in line_layer.getFeatures():
cands = area_layer.getFeatures(QgsFeatureRequest().setFilterRect(line_feature.geometry().boundingBox()))
for area_feature in cands:
...
- 4,420
12
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 - ...
- 6,410
12
votes
Accepted
Getting attribute information of multiple polygon intersected by line
Try this expression:
array_to_string(overlay_intersects('Layer_A', name))
(assuming the City names are stored in name field in the 'Layer A').
- 29.2k
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 ...
- 21.7k
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.
- 1,785
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'....
- 26.9k
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 ...
- 21.7k
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(...
- 1,135
10
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 ...
- 9,991
10
votes
Accepted
Listing IDs of polygons within another polygon in the Attribute table
A Virtual layer would work well here:
First hit 'Import' to add your layers then add the query:
SELECT A.id, group_concat(b.id)
FROM A
LEFT JOIN B ON ST_Intersects(a.geometry, b.geometry)
GROUP BY A....
- 1,495
10
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 ...
- 811
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 ...
- 24.5k
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 ...
- 53.9k
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