Questions tagged [qgis-3]

for questions specific to the 3.x series of QGIS.

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Filling field with values from field of another table using QGIS

I am using QGIS 3.28.9. I need to complete a field from a building's layer with the field's values from a plot's layer, based on the location of the buildings. At first I thought of doing it through ...
Mig TabSher's user avatar
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0 answers
41 views

QGIS shows random/wrong Values when filtering

I am using QGIS 3.28.5. I want to use a filter using Field "ART". When I click on Values to obtain different values from "ART", I get all sort of nonsense. I checked the .dbf and ...
soeren's user avatar
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Pretty "buffer" around Point-Layer with as little as possible Vertices [closed]

I'm searching a solution (which I can automate) for getting my Area of Interest around Points of Interest. I've got a point-layer in QGIS. I want to have all the area which is inside a 0.5 m Buffer ...
fsg's user avatar
  • 672
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8 views

Region of Interest selection error in Semi-Automatic Classification Plugin (Error: unable to calculate)

Yesterday I upgraded the Semi-Automatic Classification Plugin. Immediately after doing this, the automatic ROI selection is giving me that error as shown in the attached image. I have tried to ...
Aim Banda's user avatar
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0 answers
17 views

Calculate default value for field not working in QField but working in QGIS

In QGIS (3.34.3) with an input form I'm assigning as the default value of a field of my buildings polygons the code (codice) from the polygon area to which it belongs, that is stored in another layer, ...
stefan0n's user avatar
  • 184
1 vote
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28 views

Using advanced digitizing tools over multiple layers in QGIS

I need to make movements in different layer polygons at the same time (I mainly use move feature and rotate feature tools). I've seen some posts explaining how to do this in multiple steps, but the ...
Mig TabSher's user avatar
2 votes
1 answer
42 views

How to update QGIS display from script run in console

Working from the Python console in QGIS, I am trying to create an 'animation' of sorts by selecting one line after another in a layer with parallel lines, with a pause on each line. I've started from ...
marcp's user avatar
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31 views

Click Functionality Not Working in QGIS Selection Tools

Yesterday, I was using the "select entities by area or single click" tool to select a group of polygons from a shapefile and then using the "change properties of a group of files" ...
Adam Lavoie's user avatar
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18 views

Semi-Automatic Classification QGIS Plug-In Error When Running Maximum Likelihood Classifier

I have the following python error when trying to run the Maximum Likelihood classification in Semi-Automatic Classification plugin version 8.2.2 on QGIS 3.28.5. Python version is 3.9.5 File "C:\...
Sean Jarrett's user avatar
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28 views

QGIS 3.28.5 can't open a project file

Do you know any solution? I think in similar cases I could unzip the .qgz file and then I was opening the .qgs file but I can't do it with this project. I saw other answers, the file is there for ...
Pitheas's user avatar
  • 741
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29 views

Not achieving correct pixel width and height for map export in QGIS

Trying to export the full extent of a EPSG:4326 layer of the earth (-180, 180,-90,90) with an exact pixel width (8192) and height (4096). I can't seem to get the width/height correct. If I set the ...
AndrewS's user avatar
2 votes
1 answer
40 views

Adding geometry from first row of attribute table to all other rows of attribute table of layer using PyQGIS

I have a layer where only the first row in the attribute table has a geometry. I want to copy this geometry to all other rows of the attribute table of this layer but the geometry is still empty. ...
Robert B K's user avatar
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0 answers
29 views

How to generate CSV file for polygons to show in QGIS

My table looks like this: but adding this as a text defined layer hasn't got me anywhere as X and Y are not clearly defined. I am new to QGIS.
Hemproski's user avatar
2 votes
1 answer
56 views

How to hide or remove the subgroup labels on a QgsLayoutItemLegend with PyQGIS?

I'm trying to build a layout with pyqgis and I'm not able to hide or remove the label from the caption subgroup as shown in the image below. This is what I have until now: ... legend = ...
Francisco Camello's user avatar
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24 views

How to automate the code to synchronization postgis live layer on pyqgis?

I possess a dataset stored on a PostGIS server and aim to establish a fundamental synchronization mechanism through code. Although I've implemented the provided code for this purpose, when utilizing ...
Nihar Sahoo's user avatar
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0 answers
14 views

QGIS 3.34 and nested GeoJSONs

Is there an issue with how QGIS 3.34 ingests GeoJSONs that were exported by Kili with nested attributes? { "type": "FeatureCollection", "features": [ { "type": &...
Karen Kowalewsky's user avatar
2 votes
1 answer
52 views

Change selection color to be just a polygon with no fill in QGIS 3

Can we change this to be no fill color but just a yellow outline? Currently stuck in v3.16 but I don't see this in the Dev version either.
GeorgeC's user avatar
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1 answer
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Using Attribute Table in QGIS [closed]

Can the attribute table of a shape layer be modified as a dynamic table, establishing a list of options and making the work easier?
Miguel López's user avatar
2 votes
2 answers
140 views

INVALID_CHARACTER_ERR: An invalid or illegal XML character is specified

I have a shapefile. I want to load the shapefile in to QGIS but I am not able to load it. The shapefile is a layer in GeoServer (2.23.2) and loaded into QGIS (3.28.15) vis WFS 2.0.0 connection. QGIS ...
Navya's user avatar
  • 21
1 vote
1 answer
46 views

Make statistical expression for field calculator

I have a vector layer called 'Stations' and a table called 'Attitude' and a relation exists between the table's ('Attitude') "Staion_id" field and vector layer's ('Stations') "uuid"...
Redowan Sakib's user avatar
1 vote
1 answer
57 views

Why is the extent of a "point" grid different from a "polygon (rectangle)" grid in QGIS?

I cannot find an answer to this question, not even in the official QGIS documentation. Here is the problem: First, I delineate a survey area layer (geometry type is polygon): When I create a grid (...
Chavdar Kirilov's user avatar
3 votes
1 answer
160 views

QGIS Attribute Form -> Value Relation -> Filter expression: expressions or functions to get the names of current layer and current field

Shortcut to the core question: How to write a custom function to get the name of a field in an Attribute Form? I would like to use it as a variable in a Filter expression of a field with a Value ...
Bernd V.'s user avatar
  • 3,179
1 vote
1 answer
78 views

QGIS Finding Intersection of Points and Lines Layers in Electricity Grid [closed]

I am new to GIS-related work and am currently using QGIS 3.34 for my research I am trying to find the electricity grid topology and length of power lines between substations in the West of Sweden for ...
Pandu Prianto's user avatar
1 vote
1 answer
51 views

Select by location fails for some lines in QGIS

I have many line objects in a layer called "line" (pink). Further, I have line objects in a layer called "Connection" (blue). The lines in "Connection" are created by the ...
Dennis's user avatar
  • 41
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1 answer
100 views

Removing intermediate layers in processing script

I am creating a processing plugin in QGIS that has two steps. Write features to a FeatureSink. Convert the FeatureSink to a layer and perform native:joinattributesbylocation. I am using the QGIS ...
camarones95's user avatar
3 votes
2 answers
77 views

QGIS Single sided buffer value of specific area and line length on 90 degrees lines

I need to Single Sided Buffer a specific surface based on a line length, on QGIS. Example: line length: 60.367 meters. area needed from single sided buffer: 452.4 square meters. theoretic Single ...
Marin Marian's user avatar
0 votes
0 answers
15 views

Handle Unavailable Layer screen appears when using GeoJson files in QGIS project

When I open a project with GeoJson layers in QGIS 3, the "Handle Unavailable Layers" screen always opens. After using the "Auto-Find" button, the files were found without any ...
GIS_Noob's user avatar
1 vote
0 answers
53 views

How to change field type using PyQGIS?

I can change the field type (e.g. string to integer) via: Processing > Refactor fields How can I do it purely using PyQGIS via a script or the Python Console (I do not want to call the algorithm ...
user35594's user avatar
  • 555
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0 answers
40 views

How to make a simple overlay of raster layers in QGIS?

I have several raster single-band layers that share a common intersection. I want to overlay them in a certain order on top of each other in QGIS version 3.34 and save the result as a separate layer (...
senek's user avatar
  • 65
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1 answer
51 views

Including photos in a web map using qgis2web QGIS version 3.28.5

I have included a field called photo in a point layer that I want to use in a web map to be published using qgis2web. The field widget type is attachment with the path stored relative to the project ...
Sean Jarrett's user avatar
4 votes
2 answers
89 views

How to know if the map scale is set by a data defined expression using PyQGIS

Using PyQGIS, I can find the scale of a QgsLayoutItemMap using layoutMapItem.scale() or by quering the value of the variable map_scale. The following code snip finds out the current selected (layout ...
jgrocha's user avatar
  • 5,290
2 votes
0 answers
59 views

QGIS plugin testing

I have written a few QGIS plugins and would like to set up some test suites. I have one plugin that has no UI and standard unittest works. But on my plugins with UI, initiated using the plugin builder ...
MortenSickel's user avatar
  • 3,686
0 votes
1 answer
75 views

Rasterizing more than 11000 polygons in QGIS

I'm using QGIS 3.28.3. I have more than 11000 species ranges, which I want to transform into binary rasters (1 for species occurence, 0 for species non occurence), with one raster for each species. I ...
Spectron's user avatar
  • 127
1 vote
0 answers
37 views

how to add toolbar menu on pyqgis using custom class with current QgsInterface?

currently i want to add a qgis toolbar icon, which needs to be populated on the qgis window after certain process using custom class by overriding the current qgisinterface. But while running the code ...
Nihar Sahoo's user avatar
1 vote
0 answers
75 views

Geometry Generator Error. Too few points in geometry component

I've created a line layer using my point layer through the geometry generator tool described in this Creating all possible line segments between all points using QGIS Then I've used Edit Geometry =>...
redhat's user avatar
  • 347
0 votes
0 answers
27 views

Python Error with Co-registration Plugin

When using the Co-registration plugin in QGIS 3.22.3, I get the following error about phython when trying to use both the Automated local and global co-registration tools. Here is the error: "...
Nangy03's user avatar
2 votes
1 answer
45 views

Set color fill from a field containing RGB values with QGIS 3.22

I am using QGIS 3.22 on Ubuntu 22.04. I have the global ecoregions shapefile available from https://storage.googleapis.com/teow2016/Ecoregions2017.zip. This has a field called color. The values are ...
denis's user avatar
  • 71
1 vote
0 answers
33 views

Accented characters in CSV file appear as '?' when importing to QGIS 3.34.2 [duplicate]

I am trying to import a CSV set of data to join to a shapefile in QGIS but the accented characters and ñ character are displayed as missing in the attribute table and performing a join is impossible.
IDHA's user avatar
  • 11
0 votes
0 answers
24 views

Rasterization (Vector to Raster) in QGIS overwrites Maxima values of the vector

I am working on macroseismic intensity maps in QGIS 3.30. My data are in the form of a point vector. In this case, each point has an attribute corresponding to the maximum intensity which was ...
bryce's user avatar
  • 1
1 vote
0 answers
46 views

Generating an ID with date and Python in QGIS

In QGIS I would like to generate preset IDs (column name: year_id) via the attribute form. Based on the date column "date_start" the corresponding year should be recognized. It should be ...
cc_schr_gis's user avatar
2 votes
0 answers
59 views

QGIS Web View in Form does not support JavaScript ES6

I am trying to display a custom made slider with several images and files for my GIS elements. Example URL: https://eudala2.getxo.eus/slidergetxo/?width=500&height=500&codtipoexp=LMO&...
Egidi's user avatar
  • 3,728
3 votes
1 answer
45 views

Calculation using exp() function in raster calculator of QGIS fails

I have been trying to use this expression in the QGIS raster calculator: 1 / (1 + exp(-(β0 + β1 * RasterX1 + β2 * RasterX2 + ... + βn * RasterXn))) The above expression has been replaced with the ...
Andrea Pace's user avatar
0 votes
1 answer
130 views

QGIS and remote PostgreSQL/PostGIS (in cloud) slow performance

I am using QGIS 3.28.11 version and in backend I am using PostgreSQL 15.0 with PostGIS 3.3.3. I have total 36 layers which contained in 3 groups: A, B, C. Now X user has read only access on all layers ...
Rajesh Kumar's user avatar
1 vote
0 answers
53 views

QGIS export layer relations from one project to another

I have a .qgz project with a spatial layer and two non-spatial layers, primarily created for data collection. All the three layers are saved in a single .gpkg file and the non-spatial layers are ...
Abhijith's user avatar
0 votes
0 answers
40 views

Adding several different rasters to Geopackage containing project using PyQGIS

I want to store different kinds of data in a project that would be stored on a geopackage. This will allow me to have all the information I'm interested in a single file. I'm a Data Engineer and I ...
Octave's user avatar
  • 1
0 votes
0 answers
56 views

QGIS 3.28 error writing to file C:\apps\qgis-ltr\symsrv.dll Verify that you have access to that directory

I encounter this error when trying to install QGIS 3.28.13 Firenze on Windows: What can cause this error and how to solve it?
bhuvan555's user avatar
0 votes
0 answers
38 views

QGIS3 georeferencing an unreferenced PNG and it isn't showing up on my base map

I'm using QGIS3 to try to georeference a screenshot of an old map of a state park (the PNG file) to a shapefile of the park's boundaries by matching points in the park's boundary. When I tell it to ...
help-ref's user avatar
1 vote
0 answers
24 views

Improve image quality of "Decoration"

I imported a key using Decorations -> Image in QGIS 3.32 and the quality is poor, especially if the image is made smaller. I do not mean that the actual image file is small, but that displaying the ...
Nadka's user avatar
  • 51
1 vote
1 answer
70 views

Enable dragging for custom QgsAttributeTableView class PyQGIS

I have this custom class for adding an attribute table to my plugin: class CustomAttributeTableWidget(QWidget): def __init__(self, frame, layer, canvas): super().__init__(frame) # first clear ...
tbob's user avatar
  • 594
2 votes
0 answers
22 views

How can I prevent a WFS layer from refreshing on pan/zoom?

I'm using python to load a WFS layer into QGIS 3.34 - code snippet below. I've included a bounding box parameter within the url based on the current canvas extent at the time the script is run. The ...
davehughes87's user avatar

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