Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
40,219
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Specifying field type as DateTime when exporting (save feature as...) QGIS virtual layer
To extract useful data from CSV file I use virtual layer. As virtual layer are based on SQLite all field in my virtual layer are of type int, real or text.
These data need to be exported in an ESRI ...
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35
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QGIS server service file pg_service.conf not found when doing a request
Having this docker compose (v2) file for setting up a local (Ubuntu) QGIS server:
services:
qgis:
image: "camptocamp/qgis-server:latest"
environment:
PGSERVICEFILE: "/...
- 9,776
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Purchasing materials using QGIS or Qfield [closed]
I created a project for Qfield to inspect power lines. When a person has performed a line inspection, a list of materials that they need based on the inspection performed should immediately appear, ...
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NNJoin plugin crash
I'm trying to run NNjoin plugin to compute nearest distance between my plot and buildings (urban) but I'm having this error :
Here are my files (maybe not projected yet but it should be in ESPG 23839)
...
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1
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Splitting polygon that is result of difference function between two polygons in QGIS
So I have this polygon (picture 1) that will be used to make its bounding geometry as shown in the second picture.
After making this bounding geometry, I wanted to make the difference polygon from ...
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Unable to load layers in Lizmap web client geoviewer v.3.6.6 installed in Windows 11 (Workstation)
After following the installation procedure outlined in the following link: https://github.com/NaturalGIS/qgis_server_and_lizmap_on_windows, everything seemed to work correctly. Both Apache, PHP and ...
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22
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SAGA processing and special characters
I’m using some SAGA processing for vector layers in QGIS.
Is it a way to change the default encoding in SAGA?
I have attribut value with french characters (é, ê, à) and after a SAGA Union, they are ...
- 1,554
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Problem Polygon Line Intersection - SAGA QGIS
I have a ShapeFile with a series of polygons (ex: the yellow line is the common boundary between 2 polygons). I have another ShapeFile that contains a line (Pink) which crosses the limit line of these ...
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34
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Extract topology into a TIFF file
I want to extract the topology of the island is Hawai'i but when I try to do it, I get simply and empty rectangle:
I opened OSM in XYZ tiles and press the right mouse button on the layer of OSM ...
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fttx network design in QGIS: how to calculate distance to network backbone or another connected node, whichever is closer
I have a KML file of a fiber regional network (covers 2 US States) and a geocoded list of ~500 building addresses (nodes). I'd like to calculate two numbers for every address:
The distance back to ...
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29
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QGIS layout; Sum values in layout attribute table only in map window
I have produced a layout showing the polygons of grass verges to cut, and have placed an attribute table listing name and area (in m2) on the layout. I have selected 'show only features visible within ...
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Working with expressions inside variables in QGIS
This is a follow-up based on the question asked and answered here: (Using attributes tables as variables on QGIS),
I named all my layouts according to the "map_code" column + a short for the ...
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Importing a set of X-Y coordinates - data gets split and partly misplaced at the boundary of Austria GK Central and Austria GK East
I have an Excel file of coordinates of a line structure (think river or infrastructure like road, railways etc) without any info about the coordinate system except that it says GK in the X and Y ...
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45
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Change layer filter according to Map Theme in QGIS
I have a project in QGIS with configured map themes. Some layers need only certain features to be shown for each theme. Layer filter is not a part of style, so theme can't change filter. Rule-based ...
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30
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Using Baidu Map tiles in QGIS?
I am currently studying the Chinese city of Shenhzen and would like to use Baidu map tiles in QGIS. I tried using this XYZ url:
http://online1.map.bdimg.com/onlinelabel/?qt=tile&x=%7Bx%7D&y=%...
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What could be causing these crazy pixel values when I rasterize a polygon?
Here's the weird output, looks like min and max possible values for the data type?
Here's my inputs, all pixel values should be set to 0.
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Getting max value of "HeightAboveGround" inside polygons from point cloud
I have geojson file with polygons of tree locations and labels "Tree" (~5,300 polygons). And point cloud made from aerial images and points have extra information "HeightAboveGround&...
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2
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35
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Self-made attribute mask in QGIS and current_value() function
I'm working on a QGIS-Project and I tried to design my own formmask/attributemask with QT Designer. I use QGIS 3.28.12
Most of the Mask works perfectly fine, except for two things.
The second of which ...
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QGIS QSWAT help [closed]
I am using QGIS 3.26.3 and QSWATPlusLinux3_64 2.1.2 and following this guide.
The steps are as follows :
I use the "Delineate Watershed" function of Swat which is the first step.
Then I ...
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Implementing self-made attribute mask doubles combo boxes in QGIS
I'm working on a QGIS-Project and I tried to design my own formmask/attributemask with QT Designer. I use QGIS 3.28.12
Most of the Mask works perfectly fine, except for two things.
One of which I'm ...
- 91
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20
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PostgreSQL data not showing up in WFS connection in QGIS
QGIS<------>GeoServer<------>PostgreSQL DB (with geometry column)
My connections are as shown above.
Task: connect QGIS to PostgreSQL db via GeoServer such that polygon can be edited in ...
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37
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Uploading transit data to QGIS
I'm in QGIS and I've got a map of all the bus routes. The only problem is that they are all one layer, and I can't color each route individually. There isn't a property (as far as I can tell) that can ...
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How to run a yes/no query on QGIS using multiple layers for specific requirements?
I am unsure how to really word my question properly. However, I am attempting to do something specific with the data I have obtained.
I have some different layers, such as soil, topography, ...
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22
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My Enable Tracing option in QGIS has stopped working
I am currently working on a project in QGIS and my Enable Tracing feature has become blurred out and wont work. Does anyone have any ideas how to fix this?
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RuntimeError: wrapped C/C++ object of type AlgorithmDialog has been deleted - Custom Processing Script
This is my first real project for QGIS so I'm completely in the dark for the best practices. I'm working on a custom processing script within QGIS. Simply put the script uses the 'extract by location' ...
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33
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TIFF resolution decreases when opening it in the layout (QGIS)
I have a TIFF which I want to put in to the layout in order to add the legend etc. However, when I open it in the layout the resolution decreases significantly. I tried it with the TIFF as well as ...
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31
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Some labels are not shown in a rotated atlas object (QGIS 3.28.8)
I have a problem that some labels from polygons are not shown in my atlas when the map is rotated. If I switch the map rotation off all labels are placed just fine. I created the atlas objects with ...
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498
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Creating bar chart from point layer using QGIS Geometry Generator
From a layer with point geometry, I store the following fields:
"CATEG" which can be A or B
"ORDER" which is an autonumeric field sequence without repetitions
"VALUE" ...
- 1,441
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33
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QGIS: Problem to rasterize track
I'm not able to rasterize a GPS plot in QGIS (layer Chemins in red which is interpolation of GPS points) , the output is empty even though it works when I tried with a new simple layer with two line (...
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155
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Auto incremental field filled with filtered by other field value in QGIS Attribute Form
From a point geometry layer with two categories "A" and "B", when I enter new points, I first choose the category of the "CATEG" field with a listbox, and then I use the ...
- 1,441
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27
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Getting value from another table using Form-Qgis
I am creating this form.
But here I need to create a filter expression using by a field that is in another table. When the field is in the same table , I usually use an expression like this:
"...
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37
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QgsProcessingAlgorithm.initAlgorithm() is abstract and must be overridden
If I create a processing script from the template provided, I get this error (that is spammed every time I open QGIS)
I couldn't figure out a way to get rid of it
(despite the error, the scripts I've ...
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78
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Error in QuickOSM panel. I'm unable to access OSM data
I've installed QuickOSM plugin and tried to import osm data but it's showing error like this... being a beginner it's been a headache for the last few days... I'm unable to work... Searching so many ...
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32
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Problem with the 3D view in QGIS when plotting polygons
I have a polygon shapefile (projected in meters) which I want to to view it in 3D using the 3D Map Views. I attached an image of what the shp looks like in 2D (you can see I added a basemap as well ...
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82
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Label placement with callouts in QGIS
If I create point data and label them with callouts, I have the following problems:
The callouts will cross each other
The Text is over the points
It seems quite messy
I want to automate this ...
- 389
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Take colours from a raster image into shapefile
I have georeferenced an image in my project, it's a thematic map in PNG, then I have transformed it in shapefile (Poligonyze). I'm trying to take back the original thematism in the shp. Manually with ...
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40
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Showing contour lines with considering length of polyline in QGIS [closed]
How can I show contour lines with considering length of polyline in QGIS like this picture?
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63
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Making world map with terrain colours in QGIS
In QGIS I would like to create a world map that has terrain colours (e.g., deserts or vegetation), as in the attached map (Gehring et al. 2022), particularly for the African continent.
How should I ...
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41
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How to make raster from points in QGIS
I have these points and I want to make raster from this layer based on Dist2River attribute.
I used Rasterize
What should put for these to create a normal raster?
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1
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58
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Error accents and special characters
I am a master's student in Ecology and Environment in Portugal. It's been a few months since I had my first contact with QGIS.
When using a shapefile, in the attribute table, I select by expression, ...
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46
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Automatic extraction of bankfull width/depth [closed]
Does anyone have any idea about automated/semiautomated extraction of bankfull width/depth of the stream using DEM? I need suggestions on available QGIS plugins or R scripts.
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35
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Label callouts problem
I'm using QGIS 3.34, I'm having difficulty with the option of label callouts. As part of my work, I want to produce a map with buildings and their addresses. There are buildings that have several ...
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1
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50
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Generate points from raster image in QGIS
I'm hoping to generate a new vector file from select points from a raster image in QGIS. I don't know if it is possible.
For instance, I would like to generate a vector point file that puts a point ...
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2
answers
180
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Saving and applying layout of columns in QGIS Attribute Table
I have multiple projects with similar layers.
Here is an example, with all attributes (fields) visible in default order.
I do use this layout for certain tasks. But for other tasks, I wish to hide ...
- 1,656
6
votes
2
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240
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Editing width of drop down field list in the QGIS Attribute Table
Can I change the width of the drop-down field (attribute) list in the attribute table that is used for editing, i.e. the highlighted drop-down in the image below with the value "ID"? The ...
- 1,656
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34
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Missing Georeferencer GDAL Tool in QGIS, even in the installed Plugin [closed]
I am studying geography and learning how to use QGIS. I don't find the Georeferencer GDAL Tool in QGIS, not even in the installed Plugin.
What can I do?
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answer
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Image Resolution degrading when georeferencing
I have a scan of a historical map in pdf. I converted it in to png as well as tif and then georeferenced it. However, as soon as I load the image (both png and tif) in to the georeferencing tool the ...
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29
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ST_Intersection returns error in snowflake
I have two tables containing geometry columns. Table t1 holds the multipolygon data of parcels, and table t2 contains the multipolygon data of wireless coverage areas. The multipolygons in t2 are ...
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When I add my .gdb folder in QGIS my raster files don't open properly
When I drop my folder on layers panel, all data are imported but my raster that in a complex polygon convert to a rectangle and some tables.
This is my file:
https://drive.google.com/file/d/...
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21
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Change wedge buffers from arcs to slices
I recently updated QGIS to 3.34.0 from 3.22.5 and noticed the program renders wedge buffers differently from what I'm used to. They appear as arcs around a point such as
Instead of as slices of a pie ...
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