Questions tagged [qgis-modeler]

An application of QGIS used to develop models utilizing a large variety of powerful Geoprocessing tools via a GUI.

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23 views

Merge layers algorithm in graphic modeler

In a graphic modeler I select folder as input of the model and the first algorithm is "join vector layers", what I want is that the resulting layer is the base to continue the workflow of ...
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42 views

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 ...
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1answer
53 views

QGIS Model Designer - populate input options with values from postgresql database

EDIT: added further explanation with pics Is it possible to populate an input field (enum etc.), with options that are obtained from postgresql database? Similar to how you can already select database ...
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21 views

Can't include IDW interpolation in model using QGIS

I am using QGIS 3.16.10. I want to include the IDW interpolation in my graphical model but the IDW only accepts already existing layers (shapefile), but I want it to take the generated output. Can ...
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28 views

Field calculator expressions in graphical modeler (QGIS)

In QGIS 3.18. I am trying to build a model that will be used by others for a repetitive workflow involving a series of field calculator expressions. The idea is to create a new field, populate it ...
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1answer
40 views

QGIS graphical modeler and FID

I created a model to import different shape files coming from ARCMAP, to load them into my geopackage of my project. The model does different things: Delete attribute (OBJECTID, SHAPE_LENGTH and ...
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1answer
65 views

Using variable input in select by expression does not work in QGIS Modeler

I am trying to use select by expression in QGIS graphical modeler and use an input string as value inside the expression. So the model will ask the user for input (which value) and this should then be ...
4
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1answer
101 views

Adding a point to an existing layer

How can I create a point from two coordinates with the QGIS Modeling tool and add it to an existing layer?
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33 views

Automatic download of OSM data via Graphical Modeler in QGIS

I am developing a script in the Graphic Modeler, allowing to download the data of a road network from OSM data, but I cannot recover them (for the polygon recovery it works well, on the other hand for ...
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17 views

QGIS using model inputs and calculated attributes together in a model algorithm

Using QGIS 3.20.2 in the Processing Modeler I would like to use multiple fields as inputs in a dialogue box. One of those fields is calculated in a previous step. The other field is specified as an ...
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1answer
27 views

Menu has disappeared in QGIS modeler

My menu has disappeared in QGIS modeleler. How can I get it back?
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31 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 ...
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64 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 ...
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1answer
75 views

QGIS: Not possible to change the number of decimal points when using results of field calculator

When I use the modeler (Pic. 1, Layer: "Gemeindegrenze/2500 m Radius" - yellow mark), the results are always shown in a value with 16 decimal points (Pic. 2) and It seems to be impossible to ...
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1answer
50 views

Adding new row by command in field calculator in QGIS

I am actually trying to create a new field in a table with the Model Builder (Field calculator function). Is there a command that creates a new field, so I can do calculations directly in that new ...
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43 views

Conditional branch algorithm in QGIS modeler link to a certain layer and certain columm

I´ve got a modeler, which has limitation for the input. I want to build a conditional branch which stops the algorithm when the limit is overstepped. "example" - colum with numbers from ...
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1answer
45 views

Making dynamic layer using QGIS

I have a earthquake dataset that is regulary updated. I want to extract those earthquakes that falls within a given geographical area. No problem, I'll do an intersection. Then I get a temporary layer ...
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45 views

Iterate through points in QGIS Processing Graphical Modeler

I have a goal to build certain Service Areas from the points based on the distance in their attribute table. I've built a Model which takes the points and the road network. Then I've tried to use '...
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2answers
100 views

QGIS 3.16.4: Graphical modeler not running

Does anyone know the error that a graphical model can not be run at all? Following procedure: Go to "Browser" in QGIS. Execute *.model3. Do the necessary stuff like input file and output ...
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1answer
30 views

QGIS Graphical Modeler: How to execute unrelated process chain after first one is finished?

Imagine you have a process chain which ends in uploading a result to a connected PostGIS database. When this is finished, I would like to make a modification in a different table in the database to ...
2
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1answer
27 views

Translate field values from Italian to English

I want to convert the dataset for 19th century factories from Italian to English. I was thinking about typing it out in the Field Calculator like so (note the Classe column needs to be converted and ...
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36 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 ...
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15 views

Output from Mean coordinate to input of shortest path in model

I'm building a model in QGIS 3 and I want to be able to "feed" the output of Mean Coordinate to the input "Start point" of Shortest Path. The issue is that in Shortest Path I ...
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1answer
70 views

Loading PostgreSQL layer directly to QGIS Modeler

There appears to be working connections to PostgreSQL databases in the QGIS modeler. I have added and configured them and they connect to what they are supposed to but the outputs from them don't ...
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1answer
30 views

Hexbins missing points, layer extent problem in graphical modeler?

I am attempting to produce a density map by aggregating points over a hexagonal grid using a processing model as in a tutorial by Ujaval Gandhi (http://www.qgistutorials.com/en/docs/3/...
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2answers
62 views

How to centre all QGIS composers on the main map canvas

I have a template project that will be used for many future sites and I want to automatically centre all the composer layout maps to the same centre as the main canvas. Ideally this would be done as ...
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1answer
72 views

How to connect an algorithm to the input in QGIS graphical modeler?

I may well be missing something very easy, but how do you connect an algorithm in the QGIS graphical modeler to the Input? I'm following an online tutorial and have added the Inputs into the Model; ...
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34 views

Join by nearest Error: Could not convert value "LSU" to target type

I am trying to join a point shapefile to nearby sampling locations in the Graphical Modeler, but the following red text appears in the model log: Feature could not be written to ...
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1answer
85 views

Error when running QGIS graphical modeler: output of several vector layers

In order to intersect a grid according to hundreds of communes, I used the graphical modeler in QGIS to automate the process. I separated my district layer from the insee field to have as many layers ...
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37 views

Using variable field and extracting field by attribute in QGIS Modeler

I have a problem while creating a model. I want to extract certain polygons based on a field value (chain of character). The problem is the name of the field might change depending on the origin of ...
2
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1answer
52 views

Adding field containing expression from the Calculator field after executed model/script

I tried to use the refactor field processing after my model creates the two layers needed to calculate the expression: line_locate_point(geometry:=geometry(get_feature('LH_fusion', 'id', '1')), point:=...
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21 views

QGIS Processsing Modeler: fill in atlas feature in predefined print layout

I have a workflow in QGIS and print composer to generate maps with vector attributes from a filtered PostGIS layer. At the moment there are several steps to generate these maps: zoom to feature of ...
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19 views

Graphical modeler QGIS-field layer

I am making a model to intersect two layers, line and points with another one of polygons. To the intersected point layer I would like to create a new field that has a concatenation of the value of a ...
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32 views

Program works in next 30 years with QGIS over multiple layers

For an asset management plan, I want to create a table that programs work for the next 30years. For a given layer, I want to use the start date and the project into future either replacements or ...
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47 views

Using attribute as output name in QGIS Modeler

I'd like to use the following model and the results should have the names of the attributes. Unfortunately the output is not as expected.
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93 views

Refering to the input-layer of a QGIS model in field calculator expression

The setting In a QGIS model, I have an input layer polygon from which a grid is cretated. On this grid-layer, a new attribute field should be created based on an expression that refers to the input ...
2
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0answers
49 views

Use parameter in Field Calculator using QGIS Modeler 3.16

I would like to set a parameter in QGIS Modeler, which I can use as input in de Field Calculator. For example: parameter = GVG (is a string parameter) Field calculator: CASE WHEN Grondwaterdiepte >...
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15 views

Extent projection problems with v.distance to raster

I get the following error in my graphical modeler run log when trying to convert a point shapefile to a raster after running v.distance: Running Convert distance to nearest populated location to ...
2
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1answer
58 views

Rename the resulting layer of a QGIS model within the same script with PyQGIS

At the end of my processing model, it runs an "Add geometry attributes" operation. I want the resulting layer to be named "Overlap" instead of the default "Added geom info.&...
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1answer
69 views

Defining the geometric predicate as a dropdown-input of a model

I built a model and use the tool "Extract by location". I would like to define the geometric predicate as a variable, so the user can choose between different predicates when he/she runs the ...
2
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1answer
67 views

Comparing values between two fields in QGIS Graphical Modeler

I'm building a graphical model in QGIS 3.4 to check if a point feature with a specific value in the A field is within a polygon with the same value in B field. The image displays the draft of the ...
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27 views

"Join Attributes By Nearest" in QGIS Graphical Modeler Shifts Attribute Field Order

I am using the QGIS Graphical Modeler to sample a DEM using two created point features (road & pipeline) then use a spatial join to find the three closest road locations to a pipe location. The ...
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41 views

Using GPU for processing Inverse Distance Weighted within Project Modeler

We are currently doing IDW interpolation within QGIS’s Project Modeler only it is taking over 24 hours to do one run. And we have over 30 to do. Is there any way we can get it to process the data ...
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1answer
53 views

Buffer by field value in the processing modeler in QGIS

I am using the processing modeler in QGIS 3.10. I want to buffer polygons by individual field attributes. This is not a problem when I am not using the processing modeller since one can simply choose ...
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11 views

Graphical Model Stalled at v.clean of shapefile

It is difficult to give more information, but my workflow model halts any activity at the v.clean step for a polygon shapefile: It worked for other data sets, but not this one. Unfortunately, it ...
6
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2answers
260 views

Merging multiple temporal inputs in QGIS Graphical Modeler

I want to do a simple merge of some algorithm outputs in QGIS graphical modeler (not for an iterative process, like my previous question "Collect results of iterative processes in QGIS graphical ...
6
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1answer
165 views

Collect results of iterative processes in QGIS graphical modeler

I'm using QGIS graphical modeler to build an iterative process that is supposed to: extract features from vector layer 1 (VL1) overlapping with features from vector layer 2 (VL2) (iterative per ...
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0answers
30 views

Processing modeler in QGIS 3.16: connection line and wedge buffer for several points

I would like to automate two tasks using the processing modeler of QGIS 3.16. The two layers A (shown in blue) and B (orange) consists of point geometries. They should be used as input by the user and ...
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35 views

Interpreting QGIS Vector to Raster Problems in Error Log from Graphical Modeler

I am trying to convert line vectors [Line (MultiLineString)] to a raster file type, however, I have encountered some problems with the conversion process. I was trying to be careful in building my ...
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36 views

qgis2web & graphical modeler

I'm working on a modeler project. I'd like to automate the creation of web maps with qgis2web, but I can't get the algorithm 'Export vector layer' or 'Export project' work in the processing toolbox. ...

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