Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
40,202
questions
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1
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Interpolating polygon values based on neighbouring polygons in QGIS
I have many polygons, some have values, others don't. In the image, you see an example. The two grey polygons don't have values, while others have:
Is there maybe a tool in QGIS which can help with ...
- 1,105
0
votes
0
answers
20
views
Merge two GeoJSON files into one creating connection between parcel info and object info
I have two GeoJSON files, one with parcel info (multiplygons) and one with object on the parcel info (multipolygons). The files have exactly the same attributes. What would be the best way to join ...
5
votes
3
answers
308
views
Labeling count points within dissolved buffers in QGIS
I am using the following expression to visualize with a buffer, the nearest neighbors at a given distance:
case when
distance(
$geometry,
array_get(
overlay_nearest(
layer:=@layer,
...
- 1,441
0
votes
1
answer
29
views
Untwine error: Can't refer reader for a LAS file (Point Cloud File)
I was trying to import a las file to QGIS 3.28.12 Firenze. It really take me sometime to attempt to load the file but still failed to display all the points.
So I downloaded a point cloud file for a ...
- 43
2
votes
1
answer
24
views
QGIS atlas feature: Storing information from coverage layer in an atlas variable
Using QGIS` atlas feature, how can I pass information from my coverage layer to the layer's rendering engine?
At the moment, I'm abusing the Page name in the Layout > Atlas tab like this:
"...
- 153
4
votes
2
answers
140
views
QGIS Aggregate expression Function with GroupBy argument
I have a Layer "SplitNEW" which is grouped by the "group"-Column as follow:
0-RED , 1-GREEN , 3-BLUE.
The 3 Lines where previous split. Each Row in attribute table stands for an ...
- 43
0
votes
0
answers
19
views
Finding nearest points to polygon boundaries using QGIS, Points are act as Boundary landmarks
Using QGIS, am trying to determine points nearest to the polygons boundary that may act as the last landmarks at the boundary.
There quite many points, households to be precise, but I want only a few ...
- 11
1
vote
0
answers
33
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Configuring R with QGIS - scripts not running/displaying, settings checked
I have installed R scripts processing plugin but got the following error message when I run the test script:
"This algorithm requires R to be run. Unfortunately, it seems that R is not installed ...
- 31
3
votes
3
answers
146
views
Remove partly overlapping geometries from service area in QGIS
In QGIS, Service area (from point) or Service area (from layer) geoprocessing tools create 1 resp. n multipart line features which (usually) contain many overlapping sections.
Most of them can be ...
- 1,185
3
votes
1
answer
113
views
Creating dummy (random) vector layers of different geometry types, with random attributes
Problem
In QGIS, one sometimes needs some layers with dummy data just to test something: the functionality of an expression, the syntax of an SQL query in a virtual layer, creting quickly an animation ...
- 67.1k
1
vote
1
answer
28
views
QGIS data defined labelling using attribute fields in shapefile
I usually override automatic labelling by storing the X and Y coordinates of labels in manually created fields in my shapefile. I find that when using auxiliary storage in the project file, QGIS tends ...
- 21
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33
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Traced polygon on QGIS plots miles away from origin
I am trying to trace a number of polygons in QGIS but having difficulties. Once I select the second vertices it creates a point hundreds of miles away!
I have tried to create a new project and also ...
- 13
6
votes
2
answers
217
views
Shifting existing points (shapefile) to the highest raster pixel value in 5m buffer
I am trying to move 1700 points (of an existing shapefile) to a new pixel of a raster layer. If the dot is already in the highest pixel of the NDVI raster layer then no need to change.
The criteria ...
- 61
1
vote
2
answers
95
views
Showing attribute field of date type with years in four digits in QGIS
The problem
I use QGIS 3.34 Prizren. I have an attribute field of date type. Unfortunately, years are shown only with two digits: 23 instead of 2023. As a historian, this is really bad as it could be ...
- 67.1k
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1
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49
views
Select intersecting polygon in QGIS
We're trying to select an entire polygon if any part of it intersects a buffer in QGIS. How can I do this? I can get the intersecting part but can't figure out how to get the entire polygon.
To be ...
- 1
1
vote
3
answers
141
views
Extract all dangles of a service area in QGIS
I use the Service area (from layer) tool in QGIS (3.34), which allows to output the boundary nodes. I was expecting that this tool only returns the nodes at all dangles of the calculated service area ...
- 1,185
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51
views
QGIS creates gaps while generating tiles from line features with Write vector tiles (XYZ)
I try to generate vector tiles from a roads network layer, but it generates big gaps between features. It seems that some segments of the lines are being erased, while polygons and points are ...
2
votes
0
answers
32
views
Label points in QGIS with centre position preferred, but other positions acceptable
I am labeling points in QGIS without displaying a symbol.
The preferred position for the label is centred over the point, but otherwise, any placement around the point is acceptable.
Is this possible? ...
- 3,640
0
votes
1
answer
33
views
Exporting atlas using "filter by" fields
The "filter by" option in the Atlas dialogue doesn't seem to work for me. When I create a filter using an expression consisting of several fields, the atlas export includes pages which ...
4
votes
1
answer
109
views
Difference of two polyline layers in QGIS
I have an original polyline layer and a modified one representing only a part of the original network. In an example case I cut 10 meters at start and end of each feature using Geometry by expression ...
- 1,185
1
vote
0
answers
27
views
QGIS using similar colors for all attributes in a diagram
When I create diagrams in QGis and add some attributes, by default, they all have the same color which is not what I want: I want each attribute to have a dedicated color.
I've tried to find a ...
0
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0
answers
21
views
Semi-Automatic Classification Plugin Error 6 Bands Missing
Whilst getting other people to run an unsupervised (ISODATA) classification in QGIS using the SCP (semi-automatic classification) plugin, several people obtained an error message labeled 'error 6: ...
0
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0
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25
views
ERROR 1: Input values and/or interval settings would lead to too many levels
I get the following error when generating contours from a LiDAR generated DEM. I have completed this task in the past with no errors and all of a sudden, I now get this error:
ERROR 1: Input values ...
- 1
1
vote
1
answer
42
views
Editing in QGIS vertex tool
By opening a multipolygon shape file, and enabling Vertex Tool (under Edit->Edit geometry) am able to see the X, Y coordinates of the points making the polygon. When i use Vector->Geometry Tools-...
0
votes
0
answers
13
views
Train images classifier not working on orthomosaic GeoTIFF file
When I run the train images classifier on an orthomosaic or orthophoto by OTB in QGIS it generates me not just a file with .txt extension but by default it starts generating .txt.shp, .txt.shx, .txt....
- 1
2
votes
1
answer
24
views
QGIS shortcuts saved in other GUI language
My aim is to import .xml file with shortcuts saved in other QGIS user profile, in different GUI language. What could be a solution to avoid manual rewriting shortcuts?
QGIS 3.22+
- 145
3
votes
1
answer
56
views
QGIS print layout: Dynamic text with attributes from different layers with different geometry
I have made a print layout containing a map and 2 different vector layers. 1 polygon and 1 point layer.
I have used til polygon layer to control my atlas function.
The polygons are fields and the ...
- 31
5
votes
3
answers
260
views
Symbolising point shapefile in QGIS: half blue half red colored point
I have a point shapefile. I have one point which I want in two colors. One half should be blue, the other one red. It should be divided vertically.
I tried the gradient version but it is as it says a ...
- 191
3
votes
0
answers
43
views
How to use ST_LineMerge or ST_Union to merge lines in QGIS virtual layers
If have an input layer with a couple of lines, called Line with an attribute. I would like to have a virtual layer with alle connecting lines dissolved, regardless of the attribute.
input:
expected ...
- 163
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votes
1
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31
views
Is it possible to format legend text based on a field?
I have a map of companies in Europe, they are symbolised with lettered points so that I don't have to wrestle with many labels, and then the points are to be defined in the legend. What I would like ...
- 295
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0
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38
views
Import qgis.core in Azure Functions
Do any of you know if you can use qgis.core in Azure Functions to build an API?
We mainly work with Python code, where we use functions that depend on qgis.core. In Azure Functions you can easily use ...
- 5
1
vote
2
answers
52
views
How to set simple square grid as coordinate system in QGIS
I have a set of coordinates of drill sites that have x and y values ranging between 1-300. My task is to interpolate a 3D model out of them but that's easy. What I'm struggling with is setting a ...
- 11
-1
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0
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34
views
Offline Android/iOS app to view and navigate with GeoTIFF and/or georeferenced PDF maps [closed]
I work in Antarctica where my basemaps are high resolution satellite images (DEMS). I am trying to figure out the best solution for in-field navigation and viewing of said layers (could be GeoTIFF, ...
- 19
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votes
0
answers
20
views
Troubleshooting 'RasterIO error' When Cropping and Downloading .jp2 Files in QGIS with OpenJPEG and GDAL
I am trying to process large .jp2 files for image downloading from specified lat/lon coordinates using qgis's python packages. For context, I am working in a conda environment on a linux machine with ...
- 1
1
vote
0
answers
35
views
QGIS Version 3.34 ‘Prizren’ is 'not responding' on MacBook Pro
Over the past few days, QGIS has not been working well with my MacBook Pro M1 (MacOS Sonoma 14.1.1). I can upload some shapefiles, but the software freezes whenever I'm doing some process (geocoding, ...
- 11
0
votes
0
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55
views
QGIS how to improve triggers on SQL - SpatiaLite
I'm looking for a way to improve the way my triggers are working on a SpatiaLite layer.
Currently, it takes 45 seconds to work on 1000 entities. Is there a way to improve the performance?
My triggers ...
- 489
2
votes
1
answer
36
views
_core.QgsProcessingException: Unable to execute algorithm Incorrect parameter value for TARGET_LAYER
I am working on a QGIS plugin using Python with Plugin builder and QT designer with two algorithms inside "Points to Path" and "Append Features to Layer".
My plugin takes a CSV and ...
- 51
0
votes
0
answers
30
views
QGIS - SCP plugin stuck on remotior_sensus
I'm trying to follow the basic tutorial here :
https://semiautomaticclassificationmanual.readthedocs.io/en/latest/tutorial_1.html
However, on the part where I set up my first ROI and click the button ...
- 944
2
votes
4
answers
164
views
Test whether layer exists using expression in QGIS
Is there a way of testing whether a layer (name) exists in QGIS in order to write a conditional expression?
My particular problem is that I am trying to rotate a point object (a gate), using a data-...
- 3,640
1
vote
1
answer
47
views
Default location for QGIS 3.28 to save shapefiles [closed]
I understand that QGIS points to the location of shp layer files. Where are these files saved to by default so that I can find them? I have a Windows 11 PC and laptop.
- 11
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vote
2
answers
43
views
Copy Multiple Cell Values in QGIS for Filtering Purposes
I have multiple points selected, that I would like to filter out. I can copy each cell value, but that is multiple clicks. Is there a simple way to copy the value of multiple rows from a single column?...
- 11
5
votes
1
answer
98
views
Overlapping labels
I have a problem with overlapping labels from layer X to layer Y area. I want to automate my work and I'm looking for a tool to help me set the location of the label outside of layer Y (that grayed ...
0
votes
0
answers
31
views
Trouble with Buffers using EPSG:5070 QGIS
I've been trying to create a buffer layer around point sources in QGIS. I'm using the EPSG:5070 co-ordinate system, everything I input is in this system, including the base project. I've tried ...
0
votes
0
answers
20
views
QGIS - field calculator of to calculate the closest point on an arbitrary line
Trying to use the field calculator to calculate the closest point on an arbitrary line for each point in an object and append the column to the attribute table. I've had success doing the calculation ...
- 21
1
vote
1
answer
72
views
Create alternatingly colored line segment in QGIS
I have a request to carry out a task which resembles Creating alternatingly colored line from points layer in QGIS.
Is it possible to achieve an alternation of color between sections (several lines) ...
- 13
1
vote
0
answers
22
views
Different volume results in QGIS by using Raster Surface Volume and raster statistics
I have seen many questions similar to mine, but did not find an answer to my problem. I am using QGIS version 3.28.11-Firenze.
I have a raster representing the difference between two DEMs on a fluvial ...
- 11
1
vote
1
answer
24
views
QGIS Map Atlas Expression - How to refer to atlas_pagenumber in an expression for elevation symbology
Can anyone point me to an example of how to refer to the current page number of QGIS Map Atlas layout within an expression for elevation symbology (which doesn't seem possible) or alternatively how to ...
- 29
11
votes
2
answers
240
views
Creating buffers to closest distances with two categories in QGIS
I would like to develop an expression that does the following nearest-neighbour analysis:
From a layer of points 'point_layer', I would like to calculate for each point the distance to the nearest ...
- 1,441
1
vote
1
answer
41
views
QGIS Map Atlas referring to a Layout Elevation Profile item - How to refer to an item using its dislayname or id
I am using the latest version of QGIS 3.34 and trying to dynamically edit and update properties for Elevation Profiles in QGIS Map Atlas Layouts.
I am hoping to update layer and display symbols and ...
- 29
1
vote
1
answer
27
views
SVG Symbol in Attribute Table
i have few hundred records in table, i need to select them and add SVG symbol to correct one in QGIS.
I created new rule in in attribute table, then i wrote a simple rule (thats only two of much more)
...
- 41