Skip to main content

Questions tagged [qgis-processing]

Spatial data processing framework that brings advanced analysis capabilities to QGIS.

Filter by
Sorted by
Tagged with
0 votes
0 answers
19 views

Performing Empirical Bayesian Kriging in Qgis [closed]

Does anyone know if a plugin to perform Empirical Bayesian Kriging (EBK) is being developed for QGIS? I'm interested in this method because, according to Perera-Burgos et al., 2024: "EBK is an ...
Mariana GN's user avatar
0 votes
1 answer
49 views

Load results of split vector tool into group using PYQGIS

I try to write a script to automatically merge some input layers (all of the same structure) of a geopackage into one, afterwards split it by a specific attribute and save the output as geopackages to ...
Calidris's user avatar
0 votes
0 answers
26 views

MapTool in Processing Provider Plugin

I created a simple plugin using the Plugin Builder and placing the "Tool button with a dialog" option, however, as I added more things to the plugin, I saw the need to place it as a ...
Mestrexama's user avatar
0 votes
0 answers
26 views

Reduce raster file size during QGIS Python script processing

I wrote a Python script based for QGIS that is using the raster calculator to create a new raster based on two existing raster inputs. My problem is, that each output file is 35 GiB and I do have not ...
ScienceNoob's user avatar
2 votes
1 answer
75 views

Drawing rectangle of road line with width as minimum distance between two buildings in QGIS

I have two layers: line vector layer representing the road polygon vector layer representing the buildings How can I derive a rectangle shape (refer to green rectangle) for each road line whereby ...
LBL's user avatar
  • 31
1 vote
1 answer
72 views

Creating polygon layer (road border) from line layer (road) and polygon layer (buildings) using QGIS [closed]

Picture 1 showing a line layer representing road and a polygon layer representing buildings. How can I create another polygon layer for the road with the edge touching the buildings e.g. thick orange ...
LBL's user avatar
  • 31
0 votes
1 answer
64 views

How to add OpenStreetMap layer as bottom layer via QGIS processing script

I want to add an OpenStreetMap layer as the bottom layer of my project via a script. This works from the console: project = QgsProject.instance() root = project.layerTreeRoot() all_layers = root....
Nick K9's user avatar
  • 185
0 votes
0 answers
45 views

Issue with Google Earth Engine Plugin in QGIS

I am trying to resolve an error from using the Python console on QGIS. I have QGIS version QGIS version 3.34.4-Prizren on my linux Ubuntu 22.04.4 LTS, Codename-Jammy. Then I successfully installed ...
TG_'s user avatar
  • 1
0 votes
0 answers
92 views

Issue with custom QGIS process algorithm

I have a written a custom processing algorithm which iterates features within one vector layer and eliminates polygons in the second that are within each feature from the first under a specific size. ...
Steven Price's user avatar
-1 votes
1 answer
54 views

Removing 0 and NULL columns in a geopackage [closed]

I have multiple geopackages with columns containing a mix of 0 and NULL fields. I want to remove these columns where there is no value above 0. I cannot do this manually as each geopackage has 90-100 ...
ashlaff's user avatar
  • 25
0 votes
1 answer
28 views

Empty Metadata table in Semi-Automatic Classification Plugin of QGIS

I am working on Landsat 8 images using QGIS 3.36.2 When I want to convert clipped images to reflectance in Semi-Automatic Classification Plugin, nothing is displayed under the metadata table even ...
chandanr777 's user avatar
0 votes
0 answers
31 views

QGIS Processing Tools - IDW Grid not recognising point file

I'm trying to convert my point (PointZ) layer into a grid using the Processing algorithm, Grid (IDW with Nearest Neighbor Searching, but whenever I run the algorithm, I get the error: ERROR 4: `file://...
oliver's user avatar
  • 95
1 vote
1 answer
63 views

Using PyQGIS zoomToSelected(...) in QGIS Python processing script freezes map canvas

I am currently struggling with the zoomToSelected(...) function in my QGIS Python processing script. Users should select a city district via the GUI and then the tool should zoom to this feature and ...
kopi's user avatar
  • 513
0 votes
1 answer
59 views

How do I speed up selection of a large number of features

I'm looking for ways to speed up selection of a large number of features (10k+) from a list of attribute values. I'm developing a plugin to trace a pipe network, and select the tranversed pipes. The ...
timothyh's user avatar
3 votes
1 answer
122 views

Using QgsProcessingParameterEnum in QGIS Python processing script

I am currently working on a processing script for QGIS. In the function def initAlgorithm() I am defining several parameters. One of the parameters is using QgsProcessingParameterEnum with a pre-...
kopi's user avatar
  • 513
4 votes
3 answers
84 views

Snapping line on grid / cell edges

What I want to do : This question is about finding an equivalent path on a grid to a given line. The following image shows what I am trying to achieve : Starting from a generic line (in red), I want ...
TC_Blue's user avatar
  • 49
0 votes
0 answers
25 views

QGIS: "Export Mesh on Grid" not working with "Export Vector Option" enabled?

I need to sample the vector data from a Mesh to a grid, and was hoping to use the Processing Script Export Mesh on Grid, with the Export Vector Option enabled. (pic. 1) Unfortunately the whole ...
Julian W.'s user avatar
2 votes
1 answer
90 views

"Could not load source layer for INPUT: memory: not found" error in Processing Script using PyQGIS

I have a workflow where a raster should be polygonized and afterwards simplified. The simplified vector should be saved as a shapefile. I am using the template script from QGIS to create a processing ...
Freddy94's user avatar
0 votes
1 answer
28 views

QGIS model designer field name as variable in expression

I am trying to use Extract by Expression in Model Designer with the following: @SearchField ilike concat('%', @SearchWord ,'%') but it returns an empty layer. If I specify the field name like so: &...
Andrew Mercer's user avatar
0 votes
1 answer
43 views

GRASS r.viewshed not working with elevation? - PyQGIS

I'm making a QGIS plugin that uses grass:r.viewshed to analyze the area of terrain visible from different points. However, I've noticed, that when using a viewpoint where the elevation between the ...
oliver's user avatar
  • 95
-1 votes
1 answer
36 views

QGIS "Create Vector Grid" code

I need to create code in a plugin to create parallel lines at a given heading and spacing within a polygon. This is very similar to what the "create vector grid" function does. It's found ...
marcp's user avatar
  • 915
0 votes
0 answers
55 views

Accurate small-scale mile/km markers in QGIS. Qchainage and "Points along geometry" are inaccurate

Looks like Qchainage has been integrated into QGIS as "Points along geometry" and they're basically the same. But they only work in projected units so they'll be inaccurate for any small-...
James Ashton's user avatar
0 votes
0 answers
24 views

Allowing File/Folder modeler input as input for a QgsProcessing algorithm

I have a simple QgsProcessingAlgorithm from qgis.core import ( QgsProcessingAlgorithm, QgsProcessingParameterFileDestination, ) class TestAlgorithm(QgsProcessingAlgorithm): def ...
bugmenot123's user avatar
  • 10.9k
0 votes
0 answers
28 views

Correct way of calling processing algorithm multiple times with different parameters

I have a processing algorithm that loads layers, applies styling, and adds to the project. I would like to call the processing algorithm simultaneously with different parameters (batch loading). I ...
Miko's user avatar
  • 39
1 vote
1 answer
41 views

Inconsistent Vertex Counts with native:simplifygeometries Algorithm in QGIS 3.22 vs QGIS newer versions

When applying the native:simplifygeometries algorithm to the same polygon features in QGIS 3.22 and QGIS newer versions (3.28, 3.34), the resulting geometries can have a different number of vertices. ...
geavcon's user avatar
  • 221
1 vote
0 answers
46 views

QGis plugin development: method that only runs when processing tool is opened

Is there a way to run code when a processing algorithm is clicked/opened from the QGis toolbox? I'm doing an API requests in initAlgorithm() but this also executes upon QGis startup, when ...
merydian's user avatar
0 votes
0 answers
34 views

Run processing without open QGIS - for specific project

In QGIS I have this process that starts with a double click without defining parameters. I would like to start it without opening QGIS via a batch command. ATTENTION: the process must be started for ...
andreaordonselli's user avatar
0 votes
1 answer
53 views

Seeing how far you can travel by road using QGIS [duplicate]

I have 2 layers, one with roads of an area, and other with shops of the area. What I want to do is to produce a map which could show the roads that are 100m within the shops. Note that what I want is ...
Denis Rusis's user avatar
0 votes
1 answer
36 views

QGIS code for parameterAsTable / Reclassify by Table

I want to implement a QGIS Processing Tool that uses a table as input, similar to the tool "Reclassify by Table". However I can't find any doc on that. I tried to search for a respective ...
Honeybear's user avatar
  • 2,524
0 votes
1 answer
46 views

How to associate point to most recent date in overlapping polygons? (Union & v.clean is giving errors.)

I am trying to associate presence points (where a bird was sighted) in a given month (e.g. December 2022) to the most recent fire that occurred in that area. I am planning on generating a raster (5km ...
Frek's user avatar
  • 1
0 votes
0 answers
40 views

Clip function for QGIS plugin is not accurate

I am trying to build a QGIS plugin using QGIS 3.28.14, python 3.9 and in VS code environment. The problem is that when I use Native: Clip function, the resulted file has smaller area than the area I ...
Sudipta Roy's user avatar
0 votes
0 answers
47 views

Not required input layer in QGIS Graphical Modeler

I would like to know how can I use an optional (not required) input layer (used with other input required or not) in a graphical modeler of QGIS. Obviously, I uncheck "required" in the panel ...
Mark's user avatar
  • 975
1 vote
1 answer
110 views

Meaning of error message on QGIS start-up

On start up QGIS 3.36.1 on Windows 10 I get this weird error message: 2024-03-25T12:10:17 WARNING Traceback (most recent call last): File "C:\Users/Kurt/AppData/Roaming/QGIS/...
Kurt's user avatar
  • 7,107
5 votes
1 answer
116 views

Getting list of intersecting layers into a field in a polygon table

I have a polygon layer with many other layers (different geometry but no points) in a map and I'd like to return the actual layer names where any object intersects with my polygons into a comma ...
RBCMark's user avatar
  • 397
1 vote
0 answers
21 views

Elevation discrepancy while clipping a DEM in QGIS 3.28.9

I clipped a DEM (Clipped mask) using the GDAL Processing Tool - clip raster by mask layer from a DEM (clipped). The maximum elevation value of the Clipped mask is 7286m, while the same in the clipped ...
GIStree's user avatar
  • 91
0 votes
0 answers
27 views

Supressing algorithms messages in custom processing algorithms log

I would like to provide clean feedback in processing algorithms log, but it is full of intermediate algorithms results, which are cryptic and needless for user: Is there a way to suppress these ...
Kubson's user avatar
  • 614
4 votes
2 answers
283 views

Converting at once 5000 GeoJSON into ESRI Shapefiles with QGIS

I am aware that I can individually load my GeoJSON layer and save it as a ESRI Shapefile. I am wondering if anyone is aware of a tool that can bulk load and convert my 5,000 different GeoJSON layers ...
spatialuser201235's user avatar
0 votes
1 answer
73 views

Displaying loaded layer using PyQGIS

After building a plugin using Plugin Builder I've encountered an issue where selections made in a result-loaded layer are not visible in canvas. I have to zoom in or out to refresh this layer. This ...
geofausto's user avatar
  • 745
1 vote
1 answer
58 views

How to pass driver-specific options to QgsVectorFileWriter?

I would like to add layer to .gdb according to ( PyQGIS cookbook) example: # Write to an ESRI GDB file save_options = QgsVectorFileWriter.SaveVectorOptions() save_options.driverName = "FileGDB&...
Kubson's user avatar
  • 614
0 votes
1 answer
43 views

Layer attribute data being deleted

I've been using QGIS to make maps showing concentrations of study sites across regions of a country. Making the maps is ok, not problem. However, I have found, three times today, that when I close the ...
Daniel's user avatar
  • 1
1 vote
0 answers
23 views

Modify r.horizon script in PyQGIS to process each output raster after the other and save it and not waiting to the end

I installed QGIS on Google Colab and run this code first for small sample in order to check that it works there, it is perfect! from qgis.core import QgsProcessingFeedback import processing class ...
Khaled's user avatar
  • 287
0 votes
0 answers
27 views

Pydev Remote Debug Breakpoints with QGIS Stops in _string_ instead of the python file

I tried to use the remote debugger with PyDev but when I reach the breakpoint, I end up in a file name "string" that seems to be internal commands: To set up the remote debuger, I followed ...
Biorix's user avatar
  • 31
3 votes
1 answer
185 views

Combining multiple Polygons into one MultiPolygon in QGIS

QGIS 3.34.3 has a processing function "Multipart to singleparts". But what about the other way around? What is the easiest way to create a MultiPolygon from several polygons?
christoph's user avatar
  • 5,857
2 votes
1 answer
141 views

How to Delete Output of the Processing Tool in PyQGIS

I have been developing a processing tool that iterates through polygons, and for each polygon, I perform hydrological processing and call various processing tools such as 'native:clip', 'saga:...
Nil's user avatar
  • 1,574
3 votes
0 answers
138 views

Add multiple raster from a for-loop in PyQGIS

I want to use the raster calculator to add multiple rasters in PyQGIS [raster 1 + raster 2 + raster ...}. The rasters are from a for-loop. I do not manage to get the temporary files from inside the ...
eagleadmiral's user avatar
0 votes
1 answer
48 views

Python from pathlib import Path crash into QGIS

I'm creating a custom Python script inside QGIS Processing in Mac OS system, I encountered a serious error cause a crash of QGIS application. If in my Python script I use this library: from pathlib ...
gianfranco di pietro's user avatar
0 votes
0 answers
27 views

QGIS: Processing tools adding a false edge to vector layer with extreme values

I am working in QGIS 3.34.2 and several processing tools I've used so far have added a thin outline (1 cell wide?) to the edge of my area of interest (see output of aspect tool below). The vector ...
Linus's user avatar
  • 31
0 votes
0 answers
102 views

QGIS Slope: Slope processing tools not working as expected using DEM

I have a NRCS 2M DEM Bare Earth file for which I have already successfully applied the Hillshade and Aspect tools in my QGIS v3.34.1 project (see below). Now I am attempting to determine slope using ...
Linus's user avatar
  • 31
0 votes
1 answer
105 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
0 votes
0 answers
51 views

Package Layers to Geopackage stripping layers of all data using QGIS

I am having a strange issue with packaging temporary layers to a geopackage and would like to try and figure out whether I am doing something wrong before I file a bug report. I have about 180 points ...
Andy Baader's user avatar

1
2 3 4 5
33