Questions tagged [qgis-modeler]
An application of QGIS used to develop models utilizing a large variety of powerful Geoprocessing tools via a GUI.
650
questions
1
vote
0
answers
12
views
How to get attributes from the output in the graphical modeler of QGIS
I'd like to know how to get attributes (to insert it into a specific string) from the output of an algorithm which is present in a flow of the graphical modeler of QGIS. Possibly, i don't want to ...
- 769
0
votes
0
answers
28
views
QGIS model: save downloaded file with filename based on one of its attribute values
Using QGIS modeler (currently with QGIS 3.26.1) with the Download File algorithm, you can use a filename based on an expression and thus are able to give the saved file a name based on e.g. the ...
- 44.9k
1
vote
0
answers
17
views
Using folder input to pull files into QGIS graphical modeler?
My company has a script we use that pulls relevant terrain information from the web for an area and puts it into a specified folder. The files are .shp and .tiff files. Each time we use it, the file ...
- 21
0
votes
0
answers
22
views
Using multiple geopackage vector layers in modeler
I reproduce a project with the qgis graphic modeler, as it turns out some steps needed to be repeated in the future, maybe by less experienced GIS users and also for documentation purposes. However on ...
- 53
2
votes
1
answer
82
views
Model as an algorithm/processing in QGIS
I'd like to know if it is possible to use a model (previously made by the graphical modeler of QGIS) as algorithm/processing in the flow of another model.
- 769
0
votes
1
answer
47
views
Create dynamic filename, based on attribute value, for output of QGIS model
Basic idea
Every user running a model selects a folder where the output of the model, a raster, should be stored as a file. The filename should be created automatically, based on an attribute value (...
- 44.9k
1
vote
0
answers
42
views
QGIS - Graphical modeler - output shapefile is not altered
Graphical Modeller
I started using Graphical Modeler in QGIS (learned about it few weeks back and I was really excited about this). Unfortunately (probably due to lack of skill) I cannot seem to make ...
- 385
3
votes
2
answers
134
views
Create series of heatmaps for each year in QGIS
I'm working with QGIS 3.22.10-Białowieża and I've got a point layer with the attribute year. I need to create a series of heatmaps, one for each year, but I haven't found any filtering option in the ...
- 2,452
0
votes
1
answer
27
views
QGIS Graphic Desinger Add field
I am trying to design a little large model, and writing it i need to add fields and calculate them in output layer A from route finding point to point function before I append my result to the main ...
- 91
3
votes
1
answer
56
views
Field Calculator in Graphical Modeller always returns 0 or NULL
I made a simple graphical model:
A Vector Layer input with a corresponding Vector Field vf input. A Field Calculator is used to calculate a new field's value based on the selected Vector Field's value ...
- 8,818
1
vote
0
answers
41
views
If/else custom script inside QGIS Modeler
I wanted to make a small if/else custom script inside the QGIS Modeler. I want the "Centroids" algorithm to be applied when the "L" field (created earlier in the "trees" ...
- 11
4
votes
1
answer
47
views
QGIS 3 Modeler operate with a fieldname
In a model I would use a fieldname of a layer with the Input of Vector Field. When I use the name of the input in an expression, the model gives no result. Do you have any idea?
- 41
0
votes
0
answers
24
views
Loop in the graphical modeler
I'd like to know how to create a loop (an iterated process) in the graphical modeler of QGIS.
For example, i need to create some buffers of a point layer, based on a value entered by the user in the ...
- 769
5
votes
0
answers
45
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 ...
- 81
1
vote
1
answer
28
views
Using combine function in QGIS modeler
I am trying to use the QGIS modeler with the 'combine' function, but when I run the model, it only gives me one choice of shapefile to choose instead of letting me choose more than one raster to ...
- 11
5
votes
1
answer
108
views
Create biggest possible rectangular polygon from grids in QGIS
I am working in QGIS (Modeler with some Python scripting) and I have troubles performing the following task:
I have the following grid:
I have to create the biggest possible rectangle polygon out of ...
- 63
1
vote
0
answers
21
views
Disable option "open output file after running algorithm"
Whenever I run a model in QGIS there is a dialog box asking for the set parameters. There the option "open output file after running algorithm" is always checked.
is there a setting to have ...
- 21
0
votes
0
answers
17
views
QGIS Graphical modeler: load data with viscurl
Is it possible, in graphical modeler, to load data true an URL, like the algorithm download file, but I would like the data to be exposed true viscurl.
So that the source of the data should be: /...
- 794
2
votes
0
answers
65
views
Running Python script file exported from QGIS Graphical Modeller in external terminal
For instance, I have created a simple graphical modeler which gives NDVI as an output when the NIR band and Red Band are provided:
I exported the Python script using 'Export as script algorithm' in ...
- 63
0
votes
0
answers
20
views
Calling name of layer in QGIS modeler [duplicate]
I want to know how to call the name of the layer in the QGIS modeler, but I cannot find a way to do this. For exemple my layer input in 'test' is called Lake, I wanted to be able to create an output ...
- 15
2
votes
1
answer
105
views
Adding "Draw on canvas" option for the input box of Qgis Graphical Modeler
I have a very simple model created in Qgis Graphical Modeler. It takes polygon vector data as input and generates random points inside. What I want is to add an option to introduce input data using &...
- 127
0
votes
0
answers
18
views
Rename layer in model builder with almost original name
I have a model inside a model and I would like to rename the output of the model to their original name with "_clean" in front. So if the layer input its 'lake' in the project i would like ...
- 15
0
votes
0
answers
52
views
Adding new field with feature from another layer using QGIS Graphic Modeler
I'm working with QGIS 3.22.5-Białowieża under Windows environment.
I have two layers, one is the speed profile which shows (Profile_ID, Rel_speed, Time) (fig.1).
And the other is week day profile ...
2
votes
1
answer
80
views
How to save model parameters into the attribute table in QGIS?
The problem:
I have a model with several input parameters (e.g. input_holesize, input_threshold etc.). The model creates a polygon layer as its final output. I would like to save the parameters into ...
- 1,528
0
votes
1
answer
45
views
QGIS Modeler variable input for Raster Calculator
I tried the following expression to call the variable number as input on QGIS raster calculator, but it doesn't like it. In other words, what is the syntax to be used to call the number? ((version ...
- 467
1
vote
1
answer
101
views
How to fulfill condition from an enum input? [closed]
The condition that I do not do does not work
if (@step = '0.5m',"VALUE" like '%.1','')
- 77
0
votes
0
answers
48
views
QGIS Modeler and special characters
I made a model using the modeler in QGIS 3.x, almost everything works fine. My result is a temporary layer with the correct data. Exporting this layer to a shapefile using utf-8 keeps all special ...
- 13
0
votes
1
answer
97
views
Using filter expression in QGIS Modeler
Is there a way to load a saved filter expression (.qqf or .json) in QGIS Modeler and use it in the Feature filter?
2
votes
1
answer
97
views
Use outputed layers directly in QGIS modeler
I'm tring to design a QGIS model in which I'm making iterations of the "join attributes by field value" algorithm (first image). However, I can't see how to directly use the output layer (...
- 43
2
votes
0
answers
29
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. ...
- 8,818
2
votes
2
answers
71
views
In QGIS Modeler, how to merge the outputs of conditional branches of which some are performed and some are not?
I need to do a processing model that has several optional vector inputs, but that produces only one output. I have separate conditional processing branches for all inputs, but in the end I would need ...
- 21
2
votes
0
answers
38
views
How do the two sets of parameters in the Coordinate Operation processing tool interact?
QGIS' modeler provides a "Coordinate Operation" processing tool as model input. One can use it to specify the exact coordinate operation a transformation/reprojection will use.
The ...
- 8,818
0
votes
0
answers
25
views
Using refFunctions with graphical modeler in QGIS
I'm trying to reproduce a sequence of actions i made in QGIS, but this time inside the modeler.
In my process I need to collect in the lines layer the name of the polygon wich contains the line. For ...
1
vote
0
answers
34
views
Qgis 3.22.6: Field calculator in model gives back null values [duplicate]
I'm trying to calculate distance between 2 points that were previously extracted by expression. The modell right now looks like this (the other processes are deactivated):
The models input is point ...
2
votes
2
answers
66
views
Merging multiple point layers with common fields to create single table in QGIS
I have seven point shapefiles at the same geographic location with three common fields ("ID", "name2", "name3") and a fourth field, ("uni_value") that is unique ...
- 225
1
vote
0
answers
85
views
How to use raster calculator to sum multiple bands' value of a raster layer in QGIS Graphical Modeler?
I have 12 bands in a raster layer which I would like to sum up to produce a single layer. Interestingly, the raster calculator tool does the job while running it (QGIS interface)[ but fails to do so ...
- 89
4
votes
1
answer
60
views
Using values from table in QGIS Modeler for filtering
I have a list of values (species names) in a .csv file and a vector layer of sightings of many species.
Is there a way to load the list in the QGIS Modeler and use it to filter my vector layer so that ...
1
vote
0
answers
66
views
Using LIKE in QGIS Graphical Modeler
I am using the Graphical Modeler in QGIS for the first time, and would like to filter a very large point layer of postcodes in the UK by the first letter of the postcode (for now 'B') before doing a '...
- 11
2
votes
0
answers
61
views
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 ...
- 31
3
votes
0
answers
95
views
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 ...
- 31
0
votes
0
answers
34
views
TIN interpolation in graphical modeler
I am creating a new script in graphical modeler. I have an input which is « vector field » as point.
But when I use « TIN interpolation », I’m not able to select an « input of the model ». I can only ...
- 794
1
vote
1
answer
116
views
QGIS Graphical Modeler PostgreSQL Execute and Load SQL
I have a QGIS graphical model workflow that I would like to be able to use with a connected PostGIS database. I am able to export the layers into the database and associated schema, but when I try ...
- 225
2
votes
1
answer
37
views
How to share the set of models with other user?
I'm using QGIS LTR (3.22.5) and I'm working on set of models that automatize workflow in our company. The process is divided into different models, because in-between there are still some steps I can ...
1
vote
1
answer
44
views
Set name for layer is not applied when it is loaded into QGIS window with modeler
I have added a script via the modeler. When executing the same code in the script, the layers are no longer added with the specified names in QGIS but with the name of tool that was automated. ...
- 159
3
votes
1
answer
99
views
Using Point input for other algorithm in QGIS Graphical Modeler
I added a Model Input "Point Input" to my model. If I now launch the model from the Processing toolbox the user can click the ... icon and click on a point on the map.
How can I use the ...
- 8,818
0
votes
0
answers
42
views
QGIS processing modeler to PostGIS
I made a processing model in QGIS 3.10 where I calculated a integer value "mycolumn". Within the model, I refactored the "mycolumn" value to Boolean using mycolumn >= 1. As I ...
- 143
0
votes
0
answers
27
views
Quick OSM in Process Modeler give different result than QuickOSM utlity
Quick OSM in the Process Modeller give different result than the same request on the main plugin
I'm trying to download roads from Quick OSM in a process modeller, but when I try I'm sometimes getting ...
- 1
1
vote
0
answers
16
views
Referring to column that is created in previous step using QGIS Modeler
In my model I use the regular points tool. The input for the regular points tool is a shapefile for the extent and for the point spacing I would like to use a value that was calculated in a previous ...
- 343
3
votes
1
answer
87
views
Using algorithm outputs with raster calculator in QGIS model designer
I am using the Raster calculator in a model builder workflow (QGIS 3.16), but get a very unspecific error when using algorithm outputs as input for the raster calculator:
An error occurred while ...
- 1,318
0
votes
0
answers
45
views
Aligning rasters in QGIS modeler
I want to align several rasters during a QGIS modeler procedure (currently QGIS 3.16).
In QGIS Desktop I can do this using the "Align rasters" tool given in the Raster submenu:
In the ...
- 1,318