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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votes
1answer
491 views

QGIS graphical modeler add field: error executing algorithm?

I have to add more than 20 fields to a lot of shapefiles using QGIS 2.4. I used to do it with the tablemanager plugin. Beside it is time consuming, misstakes can be made. So I want to automate that ...
4
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2answers
886 views

Adding today's date into attribute table using QGIS Processing modeler?

I am looking for a way to use the Processing modeler to add a date field to an output dataset in QGIS 2.6.1 I have tried using the field calculator algorithm without success. (Also the advanced ...
3
votes
1answer
415 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 ...
7
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0answers
318 views

Merge Raster Layer Specific Order in Graphic Modeler [closed]

I'm using the Graphic Modeler/Processing Modeler to automate a process. The last step in this process is Merging three different Raster Layers. I'm using the "Merge Raster Layers" from Saga 2.0.8. Is ...
2
votes
0answers
81 views

Result names in modeler processing tools

the results of the modeler (processing tools) do not have the defined names. Is that an issue? For instance: When I'm using "clip grid with polygon" and I define the result name "clip". I expect the ...
2
votes
0answers
164 views

QGIS Problem with extract and warp modules in modeler?

I have problems using the gdal modules extract and warp in the modeler. They run correctly when started without the modeler, but when I integrate them in the modeler they won't work. The only input I ...
2
votes
1answer
44 views

How to allow the user to place a point as input for a geoprocessing model?

Is there an analogue to Esri's "Feature Set" in QGIS modeller. I am interested in creating a model that allows the user to place a point feature on a map as an input variable for a geoprocessing ...
1
vote
0answers
286 views

Raster calculation with string in modeler

In my model I have one raster file and also a string input (factor for further calculation). I tried to use the grass r.mapcalculator where I can find the raster and also the string input. I tried to ...
3
votes
0answers
191 views

Clipping and reprojecting in one process for modelbuilder // “Save raster layer as” … in modelbuilder

I want to build a model in the QGIS Modelbuilder. First it should do a clip. Afterwards it should be reprojected (from Geographic WGS84 Coordinates to Gauss-Krüger). I only see one way to do this: ...
1
vote
0answers
384 views

QGIS Graphical Modeler not finding output files

I am going through the GST 102 Module 5 tutorial which uses the graphical modeler. I keep getting this message when trying to use the output of an Extract by attribute algorithm as a clipper for a ...
3
votes
1answer
316 views

How to change parameters of certain algorithms in QGIS process modeler during run time?

I am using Process modeler to automate a bunch of things like Create Graticule -> Extract points at the graticule centeroids -> Add coordinates to the points -> update certain fields of the point file ...
2
votes
1answer
163 views

How to use inbuilt tools in QGIS Modeler?

Is it possible to incorporate inbuilt tools like, for eg: vector grid of Research tools in QGIS model builder ?
4
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0answers
755 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
votes
0answers
183 views

IS it possible to run GRASS commands in the QGIS graphical modeler?

I have a geoalgorithm set up in the graphical modeler and everything runs except for the GRASS commands. It is really frustrating because when I execute these commands on their own they work just fine ...
2
votes
0answers
141 views

Multiply Rasters with Scalar Numbers as Input in QGIS Modeler

I built a little model in the QGIS modelbuilder which uses the raster calculator with the command gt(a,threshold) I need to run the model with varying thresholds from 2 to 30 so it would be great ...
2
votes
1answer
763 views

QGIS Python Scripting - Syntax definition

After playing around with the QGIS Modeler and looking at the python scripts of what I make, I noticed some syntax which I can't find the definition anywhere. Here is a snippet of the python script ...
2
votes
1answer
709 views

QGIS Model Builder Script - Possible to merge layers in a folder?

I would like the user to select a folder via the interface in which all the vector shapefiles inside that folder would be merged. I have been using the Model Builder and looking at example scripts ...
1
vote
0answers
86 views

Error SAGA algorithms in Modeller QGIS 2.2

I am using QGIS Modeller and I try to use SAGA algorithms but it doesn't work. GRASS algorithms work just fine but SAGA doesn't. I am not sure if I have to configurate something. What is worng?
6
votes
1answer
437 views

Adding field to table using QGIS graphic modeler?

I was wondering if anyone could help as I'm struggling to get anything out of the QGIS graphic modeler. I need to be able to add a new field to an attribute table and update that field with a value ...
2
votes
1answer
2k views

How to select by attributes and calculate aggregates using Modeler?

I need to know how I can select/aggregate equal attributes in a table. This is quite the same I want to do. But I want to do it with the modeler. How to group and count attribute data? The column "...
12
votes
1answer
13k views

Syntax of conditional statements in QGIS Field Calculator(s)

I have a shapefile which I need to modify. There is one column "CLASS" with the attributes: "A", "B" and "C". I need to change "A" into "1", "B" into "2" and "C" into "3". I tried it with case when ...
4
votes
1answer
520 views

Joining csv file to vector layer in Processing modeler?

I am trying to join a simple CSV file of values to a vector layer within Processing modeller. The match would be on an ID held by both files. The CSV file has no geometry. I can do this easily in ...
2
votes
2answers
179 views

Sextante modeler feature selection

I am trying to select grids (polygon geometry) that intersect with a building layer. I can do it by using "Select by location" tool and then I generate centroids from the selected grids. There is no ...
1
vote
1answer
504 views

How to Sextante model builder within QGIS to convert KML to shapefile?

Are there any tutorials on how to use Sextante within QGIS? How I could use Sextante model builder in QGIS to convert KML to shapefile? This is a routine task and Sextante would really help. I am ...
28
votes
5answers
10k views

Seeking model builder for QGIS?

Like the ModelBuilder of ArcGIS Desktop to run simultaneous geoprocessing tools, is there any model builder available in QGIS?