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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28 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, ...
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65 views

Set mandatory output format and folder in graphic modeler

I'm working with the graphic modeler in QGIS3.2 Bonn. I have created some models and they work quite well. In order to make them more easy to use for others: Is it possible to set the output format ...
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1answer
327 views

Vector Fields as Input Variable in Field Calculator

I’m working with QGIS 3.2 Bonn and I try to build a workflow in the graphic modeler. The model aims to build variable buffers depending on values from two attribute fields of an input vector layer. ...
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1answer
221 views

Calculating vegetation indexes with GDAL raster calculator?

I want to calculate a few of vegetation indexes [ example: NDPI (red band-green band)/(red band + green band)] in a model with the GDAL raster calculator but I don't know how put the equation here:
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92 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,...
3
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1answer
150 views

Syntax for “fields to keep” of Intersection tool in graphical modeler

I'm working with QGIS 3.2 Bonn and try to set up a workflow with the graphic modeler. The model uses the Intersection Tool from the QGIS Geoprocessing Tools. The model works, but I don't want to ...
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1answer
106 views

Calling a plugin in QGIS Graphical Modeler

I am familiar with Arcmap modelbuilder but struggling with QGIS equivalent. I have installed plugin 'UMEP' and need to run 'sky view factor' module on series of rasters. Inside the Graphical modeler, ...
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212 views

Iterating polygons in folder as input in QGIS Modeler like ArcGIS ModelBuilder

How do I iterate polygons in a folder as input in QGIS modeller? Usually, ArcGIS can iterate polygons as an input for functions like union, merge, intersect, etc. But I cannot find the way to do ...
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1answer
63 views

Use of model and some tools from QGIS

(repost) This is what I want to do... Data: -raster images with 4 bands (green,red,red-edge and NIR),there are like 30 folders with one zone per folder and the images where taken 3 periods of time. ...
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1answer
72 views

Working with R and QGIS

I am performing an interpolation in R but i get the following results. What could be the issue? The script ##MySript=group ##rainfall= vector ##output= output raster require(sp) require(rgdal)...
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232 views

Model in QGIS 3 (.model3) to Python 3? [duplicate]

I try to export a QGIS 3 model (.model3) to Python but the functionality that was available in QGIS 2 doesn't exist anymore. Is there a way to export it ?
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2answers
107 views
+50

How to use fields mapper in qgis modeler?

I am building a modeler in QGIS 3.2.1, I want to use Refactor fields tool to change the name of a fixed field (fid to org_fid),This tool accepts a Fields mapping. I also noticed that there is a Fields ...
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73 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
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66 views

Creating new point based on distance of other points

I work in QGIS 2.14. I have a point layer, and I want to add points to that layer basing on the distances between the "old" point and the "new" point. I was doing it by creating buffors from each ...
2
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1answer
447 views

Import csv with x y coordinates in QGIS 3 modeler

In the modeller, I can't find a way to import a csv that has lat/long values and bring this in as a spatial file? What am I missing?
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42 views

Georeferencer in graphical modeler QGIS

Is it possible to automate georeferencing in graphical modeler, I want to extract images from a site and georeference them with QGIS. Graphical modeler algorithms won't show Georeferencer.
5
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1answer
432 views

Referencing another layer in Field Calculator inside Graphical Modeler

I want to use the Field Calculator inside the Graphical Modeler to create a new column in an input vector layer (LAYER1) using data in another layer (LAYER2). LAYER2 is the output of another algorithm ...
3
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2answers
317 views

How do I execute a field calculation on just selected records from Processing Toolbox in QGIS 3?

When I try to do a field calculation from the Processing Toolbox in QGIS 3 it performs the calculation on all records instead of the selected records. Is there a way to have the calculation performed ...
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0answers
211 views

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) ...
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0answers
51 views

QGIS Modeller - Are there system variables

In a QGIS 3.2 model can we use system variables? Basically I want the input filename to be used in the output filename. So inputName.shp -->run process-->inputName_processed.shp In arcGIS ...
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1answer
98 views

How could you measure the minimum and maximum distance to the outer edge of a polygon in QGIS

I am looking for a automatic method to measure the minimum and maximum distance from a point (represented by the star) to the outer edge of a polygon (black dotted line). I know this could be done ...
2
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1answer
44 views

More than one Field in algorithms in the Modeler Processing

Is it a way to enter more than one field in an algorithm in the Processing Modeler like in the toolbox? An example with the algorithm "dissolve" in the toolbox: The same algorithme in the modeler:
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121 views

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 ...
3
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1answer
53 views

Recovering output value in QGIS graphical modeler?

I use QGIS 3.0.3 In the graphical modeler, I use the algorithm "Basic statistics for fields". Is there a way to recover the export values in the produced html file and using them in the modeler?
4
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1answer
265 views

Graphical modeler in QGIS 3.0.3 - Access Vector Field in Calculator

I want to create an algorithm with the graphical modeler in QGIS 3.0.3 where i define one Vector Layer and a Vector Field from this Layer as my inputvariables. Then i want to access the field-values ...
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1answer
49 views

Problem with number entry QGIS modeler

i created some number entry in QGIS modeler I created them specifically for them to be decimal numbers and not integer. But when i try my model, when i put a decimal number like 0.255 the value ...
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1answer
283 views

How to link Number value with Field calculator in QGIS Modeler ?

I want to link 2 number values (RMSE & dosemax) in a field calculator formula. When I run the modeler, I add these values but it doesn't recognize them. I dont want to create a new table. Just use ...
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0answers
79 views

How to join a buffer (point) to a line in QGIS 3.0 modeler?

Is there a way to join an output buffer of a point to a line in QGIS 3.0 model processor? This is being added to a larger model so a standalone script wouldn't be practical. I am not sure if this is ...
5
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2answers
210 views

Usage of QGIS Dissolve geoalgorithm in QGIS Graphical Modeler (2.18.19 LTR)

When I use QGIS Dissolve geoalgorithm as a standalone tool from the Processing Toolbox, the GUI looks like shown below. By selecting the Input layer I am able to chose from its attributes on wich to ...
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0answers
35 views

How to Make automatic classes with algorithm in qgis modeler?

I have 1 column of numeric data in one attribute table of a layer made of points. I want to regroup this data in classes (style) with the Qgis modeler and each class must have a specific lenght that ...
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0answers
62 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 ...
6
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1answer
354 views

Cannot find layer error with Execute SQL in QGIS Graphical Modeler

I'm trying to sort a shapefile by one of its attributes using "Execute SQL", in the QGIS Graphical Modeler. Using a vector as input is working fine, but when I use a layer generated by an algorithm ...
0
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1answer
393 views

CSV list as input parameter in QGIS 3.0 Processing Modeler

I have CSV list with XY coordinates (company and its competitors) which I want to input into simple QGIS Processing model. From this list the model creates and styles two spatial layers. Everything ...
1
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1answer
84 views

'Number' input parameter can not be used by algorithms in Graphic Modeler

Does anybody knows why I use the Graphical Modeler in QGIS 3.0, the 'Number' input parameter can not be used by algorithms, I have tried the algorithms of 'Buffer', 'create grid' and others, but ...
2
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0answers
132 views

Processing modeler to update table

Not sure if I'm missing something very basic or not, but I have 6 or 7 shapefile vector layers in a dozen or so models that I need to update a single field with a rather simple formula. I could spend ...
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1answer
63 views

Create serial field following alphabetical order with QGIS using graphical modeler

I have a field with names, a string field, and I want to create another one with serial content following the alphabetical order. I have this: |Field1| | B | | C | | A | | D | And I ...
2
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1answer
96 views

Graphics modeller in QGIS

I am using QGIS 2.6 Brighton. I am trying to run a Gavrilovic model in the modeller in QGIS. FYI: Gavrilovic model is a set of Imperical equations for sediment yield analysis. The equations are as ...
0
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1answer
143 views

Cannot use GDAL algorithms in processing modeler (QGIS 3.0)

I am trying to run a fairly complex model in QGIS 3.0, but when I try to use a GDAL algorithm which uses the output of another algorithm as input, I get error messages about an unexpected '(' ...
4
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1answer
290 views

Using relative path in QGIS 3.0 Processing Modeler?

Using QGIS 3.0, we are working on creating a tool that will allow people to check that their snapping is correct with several linear features stacked on each other. A co-worker of mine figured out how ...
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2answers
595 views

Why “Export as Python script” button is unaccessible in QGIS 3.0/3.1 Modeler by default?

In QGIS 3.0, "Processing Modeler" window has no "Export as Python script" button unlike QGIS 2.x. If you look at the codes (in DlgModeler.ui and ModelerDialog.py files), you see the code lines ...
6
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1answer
198 views

How to use optional inputs in model processor for QGIS 2.18/3.0?

I have developed a processing model in QGIS 2.18 where all my inputs are optional and I need them to be truly optional. However, the model will not run unless I have all inputs present. I have tried ...
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1answer
142 views

How to generalize QGIS 3.0 Model so that I can install on multiple computers without setting up on every computer?

I am trying to create a model to work on multiple computers with little editing. I am working in QGIS 3.0. I am trying to get the model to first set the style for the layers based on a predefined qlr. ...
6
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1answer
678 views

Using QGIS 2.x processing model in QGIS 3.0?

Is it somehow possible to convert a QGIS 2.x processing model (*.model) to a *.model3 so i can run them in QGIS 3.0 without having to redo mine from scratch?
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0answers
33 views

Second grass algorithm in QGIS modeler cannot use output from first algorithm

I'm using QGIS 3.0.0 and I've created a model to delineate a watershed. The model has 3 steps: Merge 4 SRTM tiles Run r.watershed on the merged tiles Run r.water.outlet on the flow direction output ...
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0answers
85 views

Clip Shapefiles via Iteration in QGIS Python Script [closed]

I have two polygon shapefiles with several objects. Each object in both shapefiles has a given ID number. Now I want to clip the object with ID=1 in Shapefile A with the object with ID=1 in Shapefile ...
2
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0answers
56 views

Is there a way to view Qgis models from version 2.14 so they can be recreated in 3.0

I upgraded my qgis version from 2.14 to 3.0 and didn't realize that the models from the graphic modeler are not compatible. Is there a way to view or read the models so I can recreate them in 3.0? I ...
2
votes
1answer
188 views

Using CRS as parameter in QGIS Graphical Modeler

The question is loosely related to Using Calculator in QGIS Graphical Modeler since it is the same model I'm talking about. I have an algorithm ("Create Grid", in that case, but it might be any other) ...
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2answers
436 views

Using Calculator in QGIS Graphical Modeler

Since QGIS graphical modeler calculator did not lead to an answer, I'll try my luck here again. I created a simple model in QGIS 2.18.16 that shall calculate a distance based on the extent of a raster ...
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1answer
264 views

Defining a user defined CRS to a layer in QGIS modeler and then reprojecting it

How do I get the QGIS modeler to recognize and use my USER DEFINED CRS in proj4 format? I have a user defined CRS with the authid USER:100024. Its parameters in proj4 are "+proj=utm +zone=18 +ellps=...
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0answers
47 views

File overwrite error 22 in qgis graphical modeler while running modeler more than once [closed]

File overwrite error 22 'invalid file' in qgis graphical modeler while running modeler more than once, when system is restarted in there is no temporary file in qgis workspace then model runs fine and ...