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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8 views

Iterate over all attributes in QGIS Graphical Modeler

I would like to iterate over N unknown attributes in the QGIS Graphical Modeler. For example dividing all attributes in an input layer by its area to create an area weighting. I realise it could be ...
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17 views

How to call for Matrix Parameter / Enum Parameter using Field Calculator in the graphical modeler of QGis?

I am using QGis Graphical Modeler v.3 It is possible to define, as an Input, a Matrix, defined as follows: "A table (matrix) parameter for processing algorithms". I want to use values stored within a ...
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1answer
238 views

Exporting result of QGIS model to CSV

I am trying to output the result of a QGIS 3 model as a CSV file. At first I came across How to export csv/excel in QGIS3.0 model processor? but the accepted answer is not satisfying to me. Further ...
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1answer
814 views

QGIS processing default output vector layer extensions

You can set the default output-extension of a model in processing > options > general. The intermediate transactions in a model are processed in that default file format. After installing QGIS, the ...
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1answer
111 views

Issue with “Join attributes by field value” on QGIS 3.4.7

I have a shape file with polygons and a xlsx sheet, and I need to join their tables using Join attributes by field value in the modeler. At QGIS 2.18 it works perfectly, but in 3.4.7 the join doesn't ...
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17 views

Converting Model in Plug-in in QGIS

Recently, I started making a model on QGIS and now I want to transform it into a plug-in, but it seems that I have to change the code to do it, otherwise it won't work. I already have the plug-in, I ...
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1answer
31 views

Collapse rows with different attributes in QGIS modeler

I am trying to build a QGIS modeler tool to do the following; I have a parcel table with fields "OWNER" and "OWNERNO" where each owner has their own row in the table and the "OWNERNO" numbers them. (...
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1answer
35 views

QGIS 3.4.4 edit rendering styles for outputs - styles not loading

I have created a processing model in version 3.4.4 and I want the shapefile outputs from the model to load in a chosen style. I have saved the style files and used the 'edit rendering styles for ...
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1answer
179 views

File naming iteration QGIS modeler

I am attempting my first use of the modeler from the Graphical Modeler from the Processing menu in QGIS. I made a simple model for cliping species data by sanctuary.It has two Vector Inputs, uses some ...
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21 views

Using project layers as input to the graphical modeler exported script in the Python console (QGIS)

I have created an workflow wothin graphical modeler in QGIS. Now I want to use the code exported from the graphical modeler in the python console. How could I use the layers from my project as ...
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1answer
58 views

Standalone Python application from QGIS graphical modeler

I am trying to run the script generated by my graphical modeller through QGIS script. But I get the following error. # Prepare the environment import sys from qgis.core import QgsApplication #from ...
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1answer
94 views

Using input layer as output in PyQGIS for QGIS Modeler?

I have written a simple Processing script to rename a given field. It works successfully, changing the input layer's field name. However, I have not been able to produce an Output. This is a problem ...
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1answer
94 views

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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1answer
71 views

Python script from graphical modeller of QGIS 3.4 gives KeyError?

For several tasks in QGIS 3.4 I need a python script. As I am not used to use python I created the script with the graphical modeler (I modeled the tasks in the graphical modeler and exported the ...
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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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1answer
78 views

Change Output name in Script - QGIS 3

I exported a model as script using the properly option in QGIS 3.8. The Script works perfectly, but the output name is changed. Heres a print of the model: I want that the script´s output name, from ...
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34 views

Problems with Zonal Statistic in graphical modeler QGIS 3

I want to make an average of two rasters previously generated in a model but it always gives error. I have used both SAGA and GDAL to calculate the raster out of graphical modeler without problems, ...
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1answer
54 views

QGIS 3 Graphical Modeler field calculator with attribute's parameters

I want to make a model with a vector layer to calculate the sum of two parameters contained in the attribute table of the layer. I want to create two variables in the model, the name of the two ...
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1answer
49 views

Rotation goes Wrong

I have a model that I built using model builder that creates a rectangle grid and then rotates it. For some reason, when I use rotate, it creates something wrong- and it creates''holes'' between the ...
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1answer
133 views

QGIS - Script for Process Modeler, Output = Extent

just played arround a little bit with the process modeler and scripts to automate a simple workflow. I have created a simple script that should get the extent of the current layer, and then increase ...
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1answer
155 views

Incorrect result while adding points along geometry in QGIS

I'm trying to add points along lines every 3 metres but I'd like the starting/ending point at certain non fixed distance. When I use the tool 'Points along geometry' inside Graphical Modeler. I don't ...
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2answers
47 views

Realising vector file mapping using QGIS Modeler?

I pretty often get lots of vector files with different column namings. I need to produce a defined vector data file with certain columns. Is it possible to build a model that allows to make a mapping? ...
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51 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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1answer
326 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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16 views

Using Model Builder for QGIS? [duplicate]

I'm looking for a "model builder" for QGIS 3.2.1. If that kind of tool exists, could someone share some related topic showing how to use it?
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17 views

Raster Calculator in the Graphical Modeler of QGIS 2.18

How to convert this expression from raster calculator ("noise_heatmap_clip@1" <= 50) * 5 + ("noise_heatmap_clip@1" > 50 AND "noise_heatmap_clip@1" <= 100) * 4 + ("noise_heatmap_clip@1" > ...
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1answer
33 views

Using Multiple Raster Intermediate Inputs in Raster Calculator within QGIS Process Modeler

I am stringing together a series of raster calculations in the QGIS process modeler in order to calculate a surface temperature dataset from Landsat and weather data. When I use the output from ...
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44 views

Raster statistic

i'm try to use QGIS processing modeler but I've a problem. I need to use the Mean value and the standard deviation in raster calculator algorithm. I've calculated it in raster statistics, how can I do ...
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1answer
123 views

Multiplying rasters by integers in processing modeler

I need to multiply several rasters by integers as a part of a multiple steps process. For this reason I'm using QGIS' Processing Modeler. I'm looking for something similar to the Raster calculator, ...
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1answer
168 views

QGIS- Model works on single layer execution, errors out when run as batch

I have a pretty simple model in QGIS that I am trying to use as a batch process. The model takes a line shapefile input, creates a temporary buffer, extracts by location using that created buffer, and ...
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2answers
51 views

Downloading files with file paths informed by attribute information

I am looking to download files that are saved in a server location with a file path that is informed by attribute information created in the graphical modeler. The information that I would like to ...
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1answer
46 views

Adding a Geopackage layer as a hardwired input to an algorithm in the QGIS graphical modeler

I have a geopackage layer that I want to always be used in an algorithm in the QGIS 3.6 graphical modeler. When I use the triple dots to navigate to the geopackage it doesn't give me the option to ...
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1answer
29 views

QGIS Modeler - drag and drop data from ToC

Is it possible to drag and drop data from the ToC to a graphical modeler and then draw connections between data and algorithms? Also can we do the same with items in the history panel? This would ...
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0answers
88 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 ...
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0answers
18 views

Loading rasters from a GeoPackage into QGIS modeler based on attribute information?

I am looking to load raster layers from a GeoPackage based on strings of attribute information that is stored in a field. The process I am looking for is as follows: Site Boundary created before the ...
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1answer
103 views

Using variable in graphical modeler for raster calculation? (QGIS 3.8)

I am trying to create a flow in the graphical modeler using a variable in a raster calculation. Is there a way to use a variable directly in the raster calculator (SAGA or GDAL)? I know there was a ...
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1answer
419 views

Interpolating Daily Values from Monthly Grids using QGIS?

I am currently performing a bioclimatic analysis using monthly averaged climate grids. One particular calculation, Growing Degree Days, relies on daily maximum/minimum temperature and a threshold ...
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2answers
2k views

Zonal Statistics for multiple rasters

I'm trying to create a timeseries of raster data (one layer per year) by polygon (Administrative regions). Is there any way in QGIS to perform Zonal Statistics for multiple years (without having to ...
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1answer
26 views

How to enter text into attribute tables with QGIS graphical model?

I am using QGIS 2.14 to open NC files for chlorophyll satellite data with the end goal of compiling chlorophyll values for many dates (each its own initial file) in a spreadsheet. I know how to do the ...
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1answer
261 views

QGIS 3.8 model to Python script, not working in 3.4

I am using QGIS 3.4 but it does not have the option of saving a model to a Python script. So I installed QGIS 3.8, which has that option, loaded my model and saved it as a Python script. I loaded the ...
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0answers
39 views

Save Selected Features in QGIS 3.4 Model

I'm trying to build some models I have in QGIS 2.18. Each model uses the "Save Selected Features" geoalgorithm so that the model only runs on selected features in the source vector layer. In 3.4 ...
2
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1answer
48 views

Python error when batching a Graphical Modeler script [QGIS 3.4.9]

I have a very simple Model to convert a table in points and to extract some features by their attributes. I can run it without any problem, except if I do it as a batching process. I received this ...
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1answer
37 views

Writing comments in QGIS Graphical Modeler?

Is it possible to write comments in the Graphical Modeler (QGis) ? I want to explain my model step by step so anyone can easely understand what's going on.
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QGIS 3.4 Modeler gives error on non-required parameter?

I created a model which is asking to input 20 OPTIONAL parameters for vector layers. But when the user does not enter a value for any of the 20 parameters, QGIS returns an error. Traceback (most ...
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0answers
21 views

Ability in QGIS modeler to just run a step or subsequent steps in a model

In the current QGIS LTR is it possible to just run one step or all subsequent steps in a model if the previous steps have all been run and are not changed? Sometimes steps take hours to run so if ...
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0answers
41 views

When using QGIS Modeler with geopackages is there any way to Extract one Specific layer when using clip function?

I would like to use QGIS modeler to allow extraction of certain layers of a geopackage. I am trying to clip a geopackage containing multiple layers using modeler and when run it the output gives only ...
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1answer
91 views

Order of parameters in QGIS 3.6 graphical modeller

When using graphical modeler in QGIS 3.6 I have added additional parameters to the model inputs for the buffer tool. The model looks like this: When running the tool the order of the parameters in ...
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1answer
23 views

qgis:deletecolumn in QGIS 3 graphical modeler

I want to use the algorithm qgis:deletecolumn in a graphical modeler. How do I have to fill the case Fields to delete : ["field1","field2"] "field1","field2" field1,field2 [field1,field2] And is ...
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1answer
45 views

Compare two columns using Graphical Modeler in QGIS

I have a layer with several columns. One of them is called 'cod' and the other is called 'cod_2'. 'cod_2' is null, except for one row. I want to know if the numerical value of 'cod_2' is present in ...
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0answers
22 views

Copy all features and attributes to a new dataset based on a template in QGIS Modeler

In QGIS desktop I can merge a template spatial file that has no data but all the attributes I need with another spatial file that has the spatial data where some of the attributes aren't in the ...