Questions tagged [qgis-processing]
Spatial data processing framework that brings advanced analysis capabilities to QGIS.
1,100
questions
0
votes
1answer
18 views
Adding Visibility Analysis algorithms to standalone QGIS script
I'm writing a script to compute the intervisibility between two sets of points using the Intervisibility algorithm from the Visibility Analysis plugin which (to my knowledge) is installed by default ...
1
vote
1answer
21 views
QGIS modeler: using input rasters filename for naming columns by expression
I am running QGIS 3.12.3 București on Windows 10 x64; I am building a simple model to reclassify a series of rasters with a 2x3 table, and then count each unique reclassified value within different ...
0
votes
0answers
12 views
QGIS: IDW interpolation doesn't work?
Beginner user of QGIS:
I used the tool called IDW Interpolation from QGIS.
In the picture below you can see how I did it, with vector points imported from a CSV file.
However the OUTPUT is completely ...
2
votes
1answer
40 views
Convert PyQGIS processing script to plugin and get same user interface
I have written a PyQGIS processing script that can be used from Toolbox. I would like to convert this to plugin and publish. The script is taking input and output from the user through processing ...
1
vote
3answers
46 views
Set display name of vector layer in processing script
I have a processing script (QGIS 3.12) that extracts values from an input table using the native:extractbyattribute algorithm. This produces a temporary output table with the display name 'Extracted (...
2
votes
0answers
23 views
Selecting some vector layer attributes as parameter in R script in QGIS 3.10
I am doing a script of R for QGIS and I need to select only some fields of one vectorial layer. I just found these option for choose several layers but not choose several attributes.
Is it possible ...
0
votes
0answers
20 views
How to build a QGIS-3.10 script without an output layer?
So I've read about the processing scripts you can do in QGIS 3. However, there seems to be no way of just modifying a layer directly and instead I have to have an output layer, which I do not want.
...
0
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0answers
12 views
Processing script in QGIS 3: Merging layers created by earlier algorithm
I'm writing a script using the processing framework (QGIS 3,12).
Creating a buffer around a points layer using
table_with_buffers = processing.run('native:buffer', params3, context=context, feedback=...
1
vote
2answers
18 views
Save an image from the project
I took a tif file and cropped it to a portion using Raster>Extraxtion>Clip Raster by Extent. My project name is OBIA. After cropping the image is saved to this project. How do I download this image?
-3
votes
1answer
50 views
Importing map found on the Internet to QGIS [closed]
I am new to QGIS and I have learned some of the basics.
Now, I have found a Soil Map of Germany I want to work with on the internet.
My tasks now are as follows.
To reduce the size of the map with ...
0
votes
1answer
28 views
Converting shape layer with POLYGON and MULTIPOLYGON to POINT geometry
I'm trying to convert shape file to POINT geometry using QGIS 3.10.5.
Here is info of my shape file:
Here are my conversion settings:
Error that I get:
Export to vector file failed. Error: ...
1
vote
0answers
5 views
Batch processing_Distance to nearest hub [closed]
How do I go about batch processing for distance to the nearest hub? I have about 10 variables/covariates. Have tried severally and not seems to succeed.
0
votes
0answers
24 views
Save processing modeler output layers to project folder/relative path?
I am building an algorithm in the processing modeler which takes a csv file as input and creates a number of vector layers as output. I would like to automatically save these layers in the same folder ...
2
votes
0answers
28 views
Setting a relative path to load a QML style in QGIS plugin
I would like my plugin to apply a QML style to an output layer. This consists of three parts:
Packaging the QML file into the plugin.
Referring to the QML file using a relative path.
Setting the ...
1
vote
2answers
93 views
Store Result of a Processing Algorithm as a Layer in QGIS Python Script
I have converted a graphic model into a script. I want to expend this script and would like to store the result of the Reprojected Algorithm as a layer so as to get the output layers extent.
I am ...
0
votes
1answer
67 views
Using QGIS 3.12 gdal:proximity doesn't output raster file in output location in PyQGIS standalone application
I'm trying to use the gdal:proximity function from pyQGIS algorithms.
below is my code for trying to run the algorithms:
def publicgreen_qgis(self, in_fn):
params = {'INPUT':in_fn,
'...
3
votes
1answer
93 views
Disable “Selected features only” in Proccessing Script
I wrote a Progressing algorithm using Python. The tool clips DEM by a select polygon in the vector layer. If there is no selection, the tool gives an error. As the script runs anyway for the selected ...
0
votes
0answers
19 views
Increase Processing Speed on Remote Machine
I am struggling to make a large data clip (QGIS Vector Clip/GDAL Vector Clip) for an item of 1,675,220 Features with 23 Features. I have taken advantage of a remote AWS EC2 PC with 48 core CPU, 192 ...
0
votes
0answers
17 views
QGIS python error :_core.QgsProcessingException: There were errors executing the algorithm
I am trying to calculate the centroids of all polygons in a shape file, I have used this code:
import processing
processing.run("native:centroids", {'INPUT':'C:/Users/plt/Downloads/...
0
votes
1answer
37 views
Feature sink as output
I am writing a processing algorithm and I would like to return a feature sink as an output, but without treating it as a parameter. The point is I want to just add it to the table of content as a ...
0
votes
0answers
14 views
My script in pyqgis run (grass7:I.pca) runs fine but output folder empties [duplicate]
this is my PyQGIS scrpit (QGIS 3.10). this code runs fine but the output folder doesn't show results. the MyFeedBack function shows me that it runs correctly and matches the Registry that is ...
0
votes
0answers
23 views
Can't enable SAGA GIS algorithms in QGIS on Ubuntu OS
I have QGIS is 3.12.2 version and SAGA GIS 7.7 version in my Ubuntu OS.
In processing settings providers I can't enable SAGA algorithms .
In settings providers show me it is active but does not ...
0
votes
1answer
34 views
No result with processing.run(gdal: ) in standalone QGIS script
I'm unable to use any GDAL algorithm in a standalone script (QGIS 3.12.1 on Windows 10). All processing.run(native:) and processing.run(saga:) algorithms work without any problem, but when using a ...
0
votes
0answers
40 views
Why does running the script not show the file in the output folder correctly? [duplicate]
Why does running the script not show the file in the output folder correctly? The script was run in PyQGIS 3.10.
Below find the script used
import processing
import os
path ='...
2
votes
2answers
58 views
Multiplying/dividing x/y values of line and polygon layer vertices?
I have several polygon and line layers in shapefile format with no crs so it can't be reprojected. The vertices coordinates need to be divided by 3,600,000 in order for them to match the project crs, ...
2
votes
0answers
37 views
Why does “Points along geometry” in the processing toolbox take so long and is there something faster?
The points along geometry processing algorithm
Creates points at regular intervals along line or polygon geometries. Created points will have new attributes added for the distance along the ...
0
votes
1answer
62 views
I am running a processing PyQGIS script with grass i.pca but I am not getting results in my output folder
It runs without problem but I don't get the expected pca bands, my output folder is empty, I don't know what to test.
path ='C/Users/Manuel/Documents/INPUT'
output='C/Users/Manuel/Documents/OUTPUT'
...
0
votes
0answers
13 views
Batch Contour Process Broken in New Update?
When I try to run the batch processing tool for contours, it does not give me the option to save the contours as a file. This stops me from running the tool all together. Has anyone else encountered ...
1
vote
0answers
26 views
QGIS 3.4 Select by Location Returns Geometry Error - Processing Settings Ignored
I am using QGIS 3.4 on Ubuntu 18.04. I have a county wide city boundary polygon layer and a county wide building footprint polygon layer. I would like to select all the buildings that are within a ...
0
votes
0answers
17 views
Couldn't load Processing Plugin in QGIS 3.11.0 w/ GRASS 7
When I try to load the processing plug in in QGIS (version 3.11.0-Master w/Grass 7), it throws me this error:
ImportError: cannot import name 'BYTES' from 'psycopg2._psycopg' (C:\OSGEO4~1\apps\...
0
votes
0answers
28 views
Create output folder for merge result of Model Builder on QGIS 3.10
I have export my model builder to python's script and now i would like to save the result to an created folder. But the folder name is based on a layer entity. Example: I have 3 layers (city, store, ...
0
votes
0answers
29 views
Two task at the same time in Model Builder QGIS 3
I am new to using the graphic modeler and I do not know how to do certain actions.
I have several treatments to perform on the basis of a buffer zone. Indeed, I have to polygonize 2 raster (which we ...
2
votes
0answers
26 views
How can I divide a polygon in equal parts, number of parts as attribute, in QGIS?
I have a polygon layer. Each polygon is part of a street, so it's not straight or all the same orientation. Each single polygon has an attribute with a number. I would like to divide the polygons in ...
1
vote
0answers
10 views
Conical viewshed query
I have a project relating to an analysis of a national geodetic network. The data I am working with is a 0.15m pixel size dsm as well as a vector file denoting each station forming part of the ...
1
vote
0answers
31 views
Programmatically Enable/disable input parameters in a QGIS Processing plugin
Is there a way to enable/disable a parameter by a checkbox in the processing interface? In my screenshot below, I would like to disable the Output Wall Aspect Raster when the Calculate wall aspect ...
0
votes
0answers
47 views
Missing processing toolbox in QGIS 3.10
I no longer see the plugins, the processing toolbox and all the scripts in QGIS 3.10 LTR. They're not even in the "Processing" Menu. I tried looking to activate it from the menu bar but it's not the ...
0
votes
0answers
24 views
Missing Vector Pull Down Menu
I was looking to create buffers around roads that I input in QGIS but every tutorial video I looked at did it by clicking on a pull-down menu titled "Vector" which doesn't appear when I open QGIS I ...
0
votes
0answers
30 views
Is panchromatic usable for supervised classification schemes in R or QGIS?
I am using Worldview-2 and Worldview-3 panchromatic images from 2019. I am looking at discrete topographical features which are easily delineated as polygon ROIs. However, I only have this ...
0
votes
0answers
21 views
QGIS - error added after processing
I use the "difference" processing beetwen 2 layers to have polygons of layers A that do not intersect polygons of layer B. In these 2 layers there are not bad geometries and topology is cleaned. I ...
1
vote
2answers
40 views
Save numpy array as raster in a Processing toolbox QGIS3
I am trying to convert an QGIS3 plugin to the Processing Toolbox in QGIS3 but I am getting stuck on how to save my processed numpy array back to a raster file in the end.
How can I save the variable "...
0
votes
0answers
13 views
QGIS - Why are there multiple rows for each line of the line layer on which saga:crossprofiles is run via PyQGIS?
Intended result
I have a layer that contains as features individual lines of varying lengths and seek to construct a layer that contains 100 equally-spaced elevation values over the length of the ...
1
vote
1answer
52 views
Running the processing algorithm 'selectbylocation' on only over selected rows of “intersect” layer
I can run the below processing algorithm
myresult = processing.run("qgis:selectbylocation",
{ 'INPUT': selection_layer.name() ,
'PREDICATE': 0,
'INTERSECT': ...
0
votes
2answers
40 views
Pass temporary output between definitions / functions to use as input to next def
Lets say I have two functions:
class AnalyseDTM():
def __init__(self):
self.DTM = ('C:/Users/EH/QGis/Kvit_Tiny.tif')
self.CreatePolygons()
self.test()
def ...
2
votes
1answer
45 views
Delete subselected features with PyQGIS and processing
In QGIS 3.10, I have layers in which I select features by location (to find duplicates), using :
selected_features = processing.run('qgis:selectbylocation', {'INPUT':layer1, 'PREDICATE':0, 'INTERSECT'...
1
vote
0answers
47 views
QGIS crashes when deleting memory layer created by a script
I wrote some scripts that create shapes based on different sources (Excel, XML...).
These scripts follow the template on Anita Graser's site and are integrated in my processing toolbox.
They work ...
0
votes
0answers
30 views
How do I configure the “Processing R Provider”-Plugin in QGIS 3.10 on Linux Mint
I am using the "Processing R Provider"-Plugin in QGIS 3.10 running on Linux Mint 18. I have R installed, but QGIS is not able to find it:
R is installed in "/user/bin":
I have already tried to ...
2
votes
1answer
51 views
Automatic “Extract by Expression” processing with PyQGIS
Refering to this post and particulary the etrimaille's comment, I want to clean my dataset created from OSM data in QGIS.
In each layer, I want to extract the entities having a specific key and value, ...
4
votes
0answers
40 views
QGIS processing tools - saving/exporting graph
I just tried QGIS processing tools for the first time.
When using shortest path search for the first time, the algorithm is building a path graph (of course). However, the graph is never re-used. ...
0
votes
0answers
29 views
Why I can't process Landscape vector overlay of LecoS in QGIS?
I can't process Landscape vector overlay of LecoS in QGIS and I don't know why.
I have the raster layer of a district that I derived from the supervised classification, and I have buffers of every ...
3
votes
1answer
33 views
Using GeographicLib's LocalCartesian to translate LiDAR (LAS format) data onto an SBET file in WGS84
I've been working for a while now to combine LAS 1.2 formatted LiDAR data with a matching SBET file to fill in the LASF_X/Y/Z fields in the LAS file. The matching of LiDAR points to SBET trajectory ...
