Questions tagged [qgis-modeler]
An application of QGIS used to develop models utilizing a large variety of powerful Geoprocessing tools via a GUI.
249
questions with no upvoted or accepted answers
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views
Getting layer id of processing step in QGIS graphical modeler for usage within aggregate() function
How can I get the layer name or layer id of the result of an processing algorithm within QGIS graphical modeler, so I can use aggregate() function in a later processing step? Is this somehow possible ...
- 31.2k
6
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0
answers
322
views
QGIS Graphical Modeler - How to query features in algorithm output?
I have a simple graphical model that uses a Field calculator to build a URL by concatenating strings in 3 fields of its input layer. This URL should be fed into the Download File algorithm using the ...
- 13.8k
6
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0
answers
442
views
QGIS Modeler using File/Folder input paramerter
I would like to use the File/Folder input parameter to set a path for all output layer files. I was trying to connect the File/Folder parameter to my output from a model and set a default folder path.
...
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6
votes
0
answers
172
views
Creating Viewsheds in Graphic Modeler
I am trying to use Graphic Modeler to run viewsheds. As I can’t appear to use the Viewshed Analysis plugin tool in Graphic Modeler and I instead need to use the GRASS command r.viewshed.
I am ...
- 411
5
votes
0
answers
53
views
Getting maximum of raster in QGIS and use it in another algorithm
I am developing a QGIS model in which I need to get the maximum of a raster. The Zonal Statistics makes a new layer, which I don't need. The html with stats is also not useful. I just need a numeric ...
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5
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152
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QGIS Model Designer: 'Algorithm is not available' and 'NoneType' object has no attribute 'displayName'
I am building a model to automate a process of generating points at street intersections. When I run the model, there is no output. Checking the error logs, I see this:
2022-04-26T10:55:36 WARNING ...
- 61
5
votes
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answers
953
views
SQL 'insert into table(values)' using QGIS-modeller
How can I run a precalculated SQL query using QGIS-modeller to insert values in an existing PostgreSQL table?
I know I can use import layer in DB-manager to load features in an existing table, but I'...
- 5,207
5
votes
1
answer
220
views
How to Embed a table into QGIS Graphic Modeler?
I am automating a process in QGIS. So far, I have built the following model.
The HSG Lookup.csv is a user input right now. But I want it to be a predefined table(or csv file) embedded into the model ...
- 1,628
5
votes
0
answers
208
views
Using Python code from QGIS 3.x Graphical Modeler in console?
I want to use "Join Attribute by Location (summary)" processing algorithm in Python console of QGIS 3.10. After design my algorithm process (join sum of field name "abc" form layer 2 (point layer) to ...
- 1,025
4
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0
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56
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QGIS graphical modeler and raster calculator
I'm making a graphical modeler that creates me a kind of DSM, like that:
I create a DEM for my extent (I have the DEM for my whole country).
I have the Lidar for the height of the forest and I ...
- 1,493
4
votes
1
answer
239
views
Calculate the angle between line segments in a multilinestring or linestring in QGIS
I need to calculate the angle between line segments in a long chain of linestring as in the figure below:
The way I approached this is:
I assigned the id to the feature using:$id
Now each feature ...
- 305
4
votes
0
answers
62
views
Result of an SQL query in a conditional branch
I'm trying to learn how to use the graphic modeler; it's not an easy task.
In this case, I want to check in a PostgreSQL database that a table is not empty. For this I perform a "PostgreSQL ...
- 51
4
votes
0
answers
112
views
Ignoring empty output in QGIS Graphical modeler
In QGIS 3.22.11 I have a model with around 15 output, and a majority of them are empty most of the time. Is there a way to prevent layers with no entities to show up in QGIS after the model?
I tried ...
- 41
4
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0
answers
175
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Selecting and changing fields in QGIS graphical modeler
I am trying to run a model that makes a selection from a refactored and name changed field, and changes the value of the selection.
Refactoring is easy, as is making the selection within the renamed ...
- 41
4
votes
0
answers
59
views
QGIS-modeler: How to name a column of a point layer from a raster
I have several rasters named after the date and time (e.g. YYMMDDHHMM: 2107152050I) and a points layer. I want to extract the values from each raster to each of the points and therefore I created a ...
- 41
4
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213
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Graphical modeler: extract by expression on multiple sources
I'm trying to make a model in QGIS, which do the following steps:
Use the input multiple input, so I can select different vector layers (sometimes one, sometimes much more).
Use the algorithm extract ...
- 1,493
4
votes
0
answers
245
views
Merging multiple layers in folder with Graphical Model Builder in QGIS 3.10
I am trying to create a graphical modeler that merges all the layers in a folder. I am using QGIS 3.10.12. I saw in some post that there used to be saga:mergeshapeslayer but its not included in the ...
- 1,377
4
votes
0
answers
320
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QGIS Model Designer; save layer in geopackage with date
I have used the model designer to make a model in QGIS.
The model takes data different shapefiles, and runs a few algorithms.
The result is different layers loaded in an new project.
I manually store ...
- 944
4
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answers
213
views
Can Project Home variable be used to save default outputs of QGIS graphical modeler
Is it possible to use the @project_home variable in QGIS to set a default file path location for an output in the graphical modeler?
Ideally I would like the default to be the project home folder ...
- 3,140
4
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0
answers
159
views
Exporting rendered raster image from graphical modeler
I am new to using the graphical modeler and am trying to export the result raster from my model as a rendered image.
Basically trying to replicate what happens by doing the following to the result ...
- 61
4
votes
0
answers
129
views
How to make QGIS model result to be a variable?
My model's temporary result is a point layer (one feature) and I need a value from one of its fields because I want to use it in the same model to select a feature on another layer.
So for example, ...
- 1,023
4
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answers
91
views
Setting output filenames from QGIS modeler?
I have built model which iterate through features in input layer.
How I can set output filenames in the modeler using input rows?
Something like current_field_value.shp
- 71
4
votes
0
answers
198
views
How to use Hub distance in a processing model?
I am trying to make line layer (hub distance layer ) between two point layer in QGIS 2.16.
It works fine when I make layers step by step but, I want to make MODEL in processing modeler and ...
- 2,385
4
votes
0
answers
829
views
Problem loading output layer QGIS
Every time I run operations with temporary file output from the graphical modeler, I get the following error message:
Oooops! The following output layers could not be open CLIP:
C:\Users\Amine\...
- 3,454
4
votes
1
answer
614
views
What's the correct syntax for Execute SQL in Processing QGIS 2.6?
I made a small model with Processing in QGIS 2.6.
The final layer should be the result of a SQL query. Now, in the Execute SQL dialog window I can add the query:
select name, max(ele) as ele, geom
...
- 3,154
3
votes
0
answers
60
views
Modifying features in-place with a model
QGIS has some processing algorithms that allow modifying the layer's features in-place.
How can I create a tool in the graphical modeler that allows for the same in-place editing functionality, e. g. ...
- 10.4k
3
votes
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answers
449
views
How do I use spatial index to speed up a model?
I want to process data with a model in QGIS. It works fine, but the bigger the datasets get, the longer it takes. The reason is, I use GeoJSON layers and they don't have a spatial index. That is why I ...
- 2,187
3
votes
0
answers
63
views
Inline variable substitution QGIS modeler
I have a model and want to output all layers to the same geopackage.
I've added a String Input, named it workspace, set a default value like:
C:\GIS\folder\data.gpkg
And try to use it in output of ...
- 63.9k
3
votes
0
answers
277
views
QGIS graphical modeller naming layer output based on attribute
I have built a model in QGIS that buffers some points and then clips them to a paddock boundary. I would like to use the Load Layer Into Project tool or the Rename Layer tool to name the layers output ...
- 103
3
votes
0
answers
132
views
Unavailable algorithm in QGIS
When I try to launch my model (graphical modeler) in QGIS I get this message (in french) :
Cet algorithme ne peut pas être lancé :-( Le modèle que vous essayez
de lancer contient un algorithme qui n'...
- 149
3
votes
1
answer
626
views
QGIS 3 Graphical Modeler pre calculated values using Advanced Field Calculator
I have a new model that tries to create a new column using the Advanced Field Calculator and pre-calculated values. I just seem not able to get the syntax right on how to populate the attribute using ...
- 1,161
3
votes
0
answers
74
views
Processing Modeler QGIS Issues With Interpolation Step
I am trying to interpolate Sampled Points with IDW Interpolation in the QGIS processing modeler. For some reason I am not able to select the Sampled Points with the IDW Interpolation. Anyone know ...
- 167
3
votes
0
answers
35
views
Deleting input vector or raster being used in QGIS 3 modeler
As it is explained in the title I am writing a script to process this task.
The script is already written but I need it to be triggered when the inputs are not needed anymore. In other words : I need ...
- 31
3
votes
0
answers
158
views
Manually giving input and output for QGIS graphical modeler exported python script
I am using QGIS 3.
How could I manually give the input layer and the output path to the following script extracted from the graphical modeler?
It is a simple model, it takes a DEM as input and ...
- 671
3
votes
0
answers
336
views
Error while running batch processing in QGIS 3
I have built a straightforward model in the Graphical Modeller in QGIS 3.4 to select features by expression and then save the selected features to a new shapefile.
It works when running singly but ...
- 441
3
votes
0
answers
203
views
Setting input layers as PostGIS tables when building model
I am trying to build a QGIS 3.8 model where the same inputs are used each time and only the clipping layer extent changes.
I can do this using shapefiles and editing the script to use the same input ...
- 1,100
3
votes
0
answers
898
views
QGIS3 run model with python script
I want to run a model with a python script, including the parameters, because I can't "translate" the model easily into a script.
I have tried to run a copy of the processing log after running the ...
- 411
3
votes
0
answers
155
views
How to chain multiple field calculators in QGIS Modeler with pointers on next or previous feature?
I have a Model that I use to filter a chain of points that have extracted values form a DEM (digital elevation model). I want to smoothen the hights with a filter that takes the average of the ...
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3
votes
0
answers
902
views
Getting Minimum and Maximum Values of Raster Layer using QGIS Raster Calculator
I try to work with the minimum and maximum values of a raster layer in the raster calculator in QGIS 3.6. I try to do the following formular:
( @RasterCellValue - @RasterMinValue ) / ( @...
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3
votes
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answers
43
views
Error in Graphical Modeler when converting raster to vector
I'm building a model where, among other things, I use r.watershed, from which I only keep the "stream segments" output.
In addition I would like to convert that raster to vector lines. When I do that ...
- 941
3
votes
0
answers
458
views
QGIS: processing-modeler to add multiple layer name to attribute field
I'm trying to add layer name using the field-calculator in QGIS (3.4.1). If I do this manualy it works fine, but if I do this using the processing-modeler I get NULL for every field. I just type @...
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3
votes
1
answer
629
views
Alternative to 'Table' input in QGIS 3 Modeller
In QGIS 2 graphical modeller I had an input parameter 'Table' for spreadsheets, CSV etc. with no geometry. By now, I'm re-creating all my existing QGIS 2 models from scratch (cp. Using QGIS 2.x ...
- 14.3k
3
votes
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answers
280
views
Convert polygons to lines ignoring redundant vertices in QGIS
Provided the following Polygons layer with 6 polygons (see image below), I would like to calculate each line's segment's angle (amongst other things), so I should convert those six polygons into lines,...
- 872
3
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0
answers
496
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QGIS spatial sort - coalesce?
In QGIS (v3.2) is there a spatial sort similar to ArcGIS (http://desktop.arcgis.com/en/arcmap/latest/tools/data-management-toolbox/how-sort-works.htm#ESRI_SECTION1_9C199CD3D68A41029943D4FF79500A73) ...
- 7,944
3
votes
0
answers
234
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Using raster calculator inside graphical modeler
I have an issue, which I am struggling with since few hours - I've built a model which aims to make multicriterial analysis based on few vector layers and DEM.
At the step which is problematic for ...
- 31
3
votes
0
answers
176
views
QGIS Modeler Layer order
Is there a way to Order the way Layers are displayed when adding them to a process in the modeler?
I am trying to add 4 layers to a VRT process before using a Clip by polygon function and the problem ...
- 1,100
3
votes
0
answers
113
views
Python stops during band algebra in GDAL calculator within modeler in QGIS
I'm trying to calculate four greenness indices using the GDAL calculator within the graphic modeler in QGIS 2.14.7 Essen.
The tool systematically crashes with a Windows message stating that Python ...
- 438
3
votes
0
answers
345
views
Multilevel b-spline crs issue in modeler
I'm struggling with a processing modeler tool. I have a point shapefile (WGS84) which I want to interpolate with the SAGA spline tool. The model is reprojecting the wgs84-points to UTM32N (EPSG:25832)....
- 2,315
3
votes
0
answers
1k
views
Download OSM data with QuickOSM and QGIS Modeler
I've been using QuickOSM plugin for some time and I would like to create some model that allows me to automate OSM data dowload in order to make sure that I am always working with the most updated ...
- 872
3
votes
0
answers
433
views
Splitting OSM data into layers by tags (QGIS modeler)
I have a problem with using the QGIS modeler to split a downloaded .osm file into layers. What I am trying to achieve is a structure like this:
Traffic (lines)
Main Roads
Roads
Small Roads
Natural (...
- 331