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19 votes
Accepted

Creating animated light cone of a lighthouse and part of coastline covered by light in QGIS

Before starting, make sure your point layer contains an attribute speed that contains values for the speed of the light cone for each lighthouse (point). Framerate of 20 fps, left point with speed of ...
Babel's user avatar
  • 72.7k
11 votes
Accepted

Point Clustering in QGIS, but values show a percentage and not count of points

The displayed number is part of the point clustering symbol. To modify it, click on the cluster symbol: Then select the font marker and click the epsilon for the character data override: Edit it and ...
JGH's user avatar
  • 42.3k
11 votes

Symbolising point shapefile in QGIS: half blue half red colored point

To just show another possibility: you can use Geometry Generator and create wedge buffers. The advantage is that A) you have only one symbol layer and B) you can use it to create even more complex ...
Babel's user avatar
  • 72.7k
10 votes

Points not showing on map on QGIS

Look at the layer's order, it is because OpenStreetMap layer is covering everything. Just drag down the OpenStreetMap to the bottom of the layer list. It should fix your problem.
GforGIS's user avatar
  • 3,126
10 votes

Creating bar chart from point layer using QGIS Geometry Generator

Let's assume there is an input point layer called 'points_in_polygon' with its attribute table, see the image below. Attributes Imitatation : "city" → "CATEG" "month" → ...
Taras's user avatar
  • 33.2k
10 votes
Accepted

Connecting dynamically the 8 nearest lines to @map_extent_center in QGIS

Create the lines from all points to the center of the map canvas with your expression, but aggregate them into an array with array_agg(). Inside the array, order the lines according to their length, ...
Babel's user avatar
  • 72.7k
9 votes

Symbolising point shapefile in QGIS: half blue half red colored point

In QGIS you have to go to: Layer Properties > Symbology > Symbol selector > Simple Marker > scroll down and select the half circle > Rotation: 90° For the second half circle: add ...
Lina's user avatar
  • 233
8 votes

Removing duplicate point features using QGIS

You can use the QGIS built-in tool named "Delete duplicate geometries" under Processing Toolbox" > Vector general in the Processing Toolbox (Ctrl+Alt+T).
Kadir Şahbaz's user avatar
8 votes

Determining on which side of line points are located using QGIS

You can also use QGIS expressions for this. See below for the expression to get a 0 or 1 output for each point, depending on which side of the line it is (see below for curved lines). The solution is ...
Babel's user avatar
  • 72.7k
8 votes
Accepted

Adding simple Geomasking (Donut masking) feature using PyQGIS

Preamble: Unfortunatelly I did not read your articles, but I hope I understood your issue correctly. Let's assume there is an input point layer called 'points2', see the image below. The task is the ...
Taras's user avatar
  • 33.2k
8 votes
Accepted

Creating buffers to closest distances with two categories in QGIS

You will need the computed distance to classify the output. One option is to create a virtual layer that will compute the distance, record it, buffer the point and that you can style as you wish using ...
JGH's user avatar
  • 42.3k
8 votes
Accepted

Creating bar chart from point layer using QGIS Geometry Generator

Use the following expression in Geoemtry Generator, style the resulting line as arrow and assign the color corresponding to the category values (see below for that). The expression creates a bar chart,...
Babel's user avatar
  • 72.7k
8 votes

Triangulation in QGIS

A stepwise approach to get the coordinates. First I show how to create the lines, and afterwards how to get the coordinates of the points where they cross. To imitate a real-world example, the lines ...
Babel's user avatar
  • 72.7k
7 votes

Determining on which side of line points are located using QGIS

In PyQGIS 3 there is a handy method available, namely segmentSide() from the QgsGeometryUtils class. Let's assume there are two layers: a line layer with a single feature, and a point layer with nine ...
Taras's user avatar
  • 33.2k
7 votes
Accepted

Delete default shadow's points in QGIS

As this really look like the "drawing effects" and as you can set several effect on the same symbol in different place I think you have disabled the "Layer" rendering drawing ...
J.R's user avatar
  • 16.5k
7 votes

Creating buffers to closest distances with two categories in QGIS

Alternative solution I use Rule-based symbology with the following expressions: For Filter (calculate distances for each point and select distance <0.7): distance( $geometry, array_get( ...
Ingrid Ingravida's user avatar
7 votes

Labeling count points within dissolved buffers in QGIS

This isn't a complete answer but might provide you or others some ideas to combine with other suggestions. Considerations: Assumes you are OK with clustering algorithm approach (not necessarily same ...
she_weeds's user avatar
  • 12.6k
7 votes
Accepted

Extracting two closest points with matching ID and create line between both points in QGIS

In theory you should be able to adapt your expression to include a filter as follows: with_variable('layer_a_id',$id, make_line( overlay_nearest( layer:='Layer_B', ...
Tom Brennan's user avatar
  • 5,239
6 votes
Accepted

How to draw 8 lines away from every point in a layer using QGIS?

Geometry by expression with output geometry type line and expression below. Adjust the distance parameter: collect_geometries( array_foreach(array:=generate_series(start:=0, stop:=315, step:=45), ...
Bera's user avatar
  • 74.4k
6 votes
Accepted

Labeling count points within dissolved buffers in QGIS

What is a bit tricky: expressions work on a per-feature basis, so there is no direct way to only label the dissolved buffer (and any indirect way would be too complicated for the task, an overkill). ...
Babel's user avatar
  • 72.7k
6 votes

Label placement with callouts in QGIS

Regarding point 3: If your intention was to use a geometry generator for the symbol to make it behave like a polygon in terms of label settings, that won't work. You need to use the geometry ...
she_weeds's user avatar
  • 12.6k
6 votes

Deleting points in in certain area using PostGIS

A bit more idiomatic, using a potentially faster NOT EXISTS: WITH -- get a GEOMETRY representing the areas to keep aoi AS ( SELECT ST_SetSRID( ST_Extent(geom), 4326 ...
geozelot's user avatar
  • 30.4k
6 votes
Accepted

Dropping nearly-identical point locations with GeoPandas

You can round the coordinates of the geometries first using shapely.set_precision: # Round the coordinates to 5 decimals gdf.geometry = shapely.set_precision(gdf.geometry, grid_size=0.00001) Note: in ...
Pieter's user avatar
  • 2,994
6 votes

Creating tangential lines at points along shoreline in QGIS

This can be achieved with a Geometry by Expression / Geometry Generator expression. -- find the nearest line to the current point (change 'coast layer' for the name of your line layer) with_variable('...
Matt's user avatar
  • 17.4k
5 votes
Accepted

Set points according to coordinates using QGIS 3

You can use Advanced digitizing tool to lock the coordinates, then place a point anywhere: But if you have many points to place, you can save them in a csv table and add as a delimited text layer. ...
Bera's user avatar
  • 74.4k
5 votes

Removing duplicate point features using QGIS

Another solution is the SAGA's "Remove Duplicate Points" tool can be found under SAGA > Features - Points in the Processing Toolbox (Ctrl+Alt+T).
Taras's user avatar
  • 33.2k
5 votes

How to draw 8 lines away from every point in a layer using QGIS?

Depending on how you want the lines created (for display or as a layer), one option would be with a Geometry Generator expression under the Symbology tab of the Layer Properties: Essentially you ...
Tom Brennan's user avatar
  • 5,239
5 votes

Creating SVG point symbol depending on content of attribute field in QGIS

No need for python or sql, simply use data driven override for the svg source. I have a point layer with a field symbol, containing the names of different amenities. In the data driven override, I add ...
Babel's user avatar
  • 72.7k
5 votes
Accepted

Dynamically drawing the polygon formed by nearest points to @map_extent_center in QGIS

You can simply create the concave hull around the points you have with function concave_hull(): with_variable( 'min', array_sort (array_agg (ELEVATION),0)[10], concave_hull( ...
Babel's user avatar
  • 72.7k
5 votes

Labeling with comma as in QGIS Attributes table

If you have QGIS 3.28 or newer, you can use this expression to remove the thousand separator:** format_number("Area", places:=1, omit_group_separators:=true) You need to use the ...
Kalak's user avatar
  • 3,854

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