Questions tagged [qgis-3]

for questions specific to the 3.x series of QGIS.

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4 views

PyQGIS grass7:v.distance parameter error “The number of columns and the number of upload parameters should be equal!”

I am currently working on a Python script for QGIS in which I would like to obtain the (minimum) distance from each point (polygon centroid) in the points layer centroid_layer to the line layer ...
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5 views

QGIS 3.10 fails to install plugin (Waternetanalyzer) from repository

I wrote a plugin which is installed properly in QGIS 3.4, ... QGIS 3.9. But it cannot be installed from the repository in QGIS 3.10. An error occurs (see picture below) and no tools are added to the ...
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1answer
13 views

Refresh Oracle Layer with PyQgis

I'm working on a Dockwidget with PyQgis. I made an insert into an Oracle DB and I would like to see the new insert (it's a point). The Layer where the new point is add is URB_A_ADPT. I'm sure the ...
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1answer
35 views

Dynamic decoration QGIS3

I try to make «copyright» decoration in QGIS dynamic. I have a surface layer «COMMUNE» with a "NAME" field. I try to write an expression that allows me to display this "NAME" in the decoration, I ...
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0answers
19 views

Extending QGIS wordwrap function

I've got an idea that I'd like to try in order to extend the QGIS 3 "wordwrap" label engine function. Ultimately, I'd like to enable users to set min and max length for a single line, and then wrap ...
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1answer
27 views

A loop to select all active layers in a project [duplicate]

I am trying to export all active layers in a QGIS project to a specified folder, below is what I get atm Outputdir='C:/Users/DN/Downloads/Test/' layer = iface.activeLayer() QgsVectorFileWriter....
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31 views

Creating a Heatmap of Delivery Probability in QGIS3

Im using QGIS 3.4.2 to create a heatmap to plot the source place where a network message is generated, in a vehicular network. I separated the messages in two groups, one in each layer: delivered and ...
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16 views

Insert/append list values to a layer using QGIS Python [on hold]

I have created a list in the format of a layer. I need to insert/append the values of list in to the layer as new row/data. Also this data has no geometry. How can I do this?
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1answer
48 views

Calling the correct element of an output via PyQGIS Script

I am trying to apply a style to the output file of a script that I´m running from the toolbox in QGIS 3.4.7. The last step is as described below. def processAlgorithm(self, parameters, ...
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1answer
68 views

QGIS: create lines to connect points which are within a distance to each other

I have a point layer and I'm Looking for a tool wich connects every point of the layer with each other. Ideally, I can give a distance and the number of Connections for each point. The following ...
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2answers
51 views

Adding own items into QGIS 3.10 news feed?

Is there a possibility of adding own items into the news feed of QGIS 3.10? As a GIS administrator it would be a great tool to spread GIS/QGIS related news to internal colleagues.
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28 views

Find distance between multiple discrete sets of points QGIS3.8

No similar question seems to relate to my issue but I desperately need help with calculating distances. I have a CSV with the residential postcode of 200 000 patients. For each patient, I also have ...
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22 views

How to change a widget type of a field by using python

I'm working on a plugin for QGIS 3.x and I'm looking for an example how I can change the widget type by using Python code. The change should be applied on fields of a vector layer. At the end it ...
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12 views

Garmin/Navionic charts in QGIS

I'm looking for an option to import nautical maps (mostly for depth data) into QGIS. So far, I managed to import NOAA .KAP files, but coverage and resolution of some areas are not very good. Is there ...
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1answer
35 views

How to homogenize NA values within a .gpkg from R

I have created an SpatialPointsDataFrame in R with some data. Here is the outputs from R: > class(Fotos) [1] "SpatialPointsDataFrame" attr(,"package") [1] "sp" > class(Fotos$Azimuth) [1] "...
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0answers
18 views

Change the colors of the pie chart in compouse (plot) in QGIS 3.10

When using the new plot command available in QGIS 3.10 for compouse pie chart generation, I didn't find any option to change colors. Is there any way to choose colors?
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1answer
26 views

Qgis 3 : QgsEditorWidgetSetup for date

I need to make a date format in QGIS 3 but, in the program I need to use, QgsEditorWidgetSetup('Date',{'yyyymmdd'}), I want to get this: But I don't know how to use QgsEditorWidgetSetup to make the ...
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0answers
15 views

Which type of slash to use in path - QGIS 3.8 with Python [on hold]

I'm a beginner using Python. I had a problem loading a shapefile in QGIS 3.8 using Python, while loading a rasterfile worked perfectly. I found the solution here: Can't load a shapefile with ...
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0answers
37 views

Balancing multiple supply and demand locations in QGIS

I am looking for a way to balance supply and demand with respect to distance, between two vector layers in QGIS. I have two vector layers 50x50m grid Supply (The red negative values) Demand (The ...
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0answers
24 views

What is happening with the centroids that are not on the road layer when you use the Shortest path (layer to point) from Network Analysis?

I am using QGIS 3.8.1 and I want to compute the shortest path of the centroids of any commune to Paris using the roman network. The centroids are the yellow points the road net is the green lines. ...
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1answer
36 views

QGIS: Creating custom CRS without using the GUI

What would be the appropriate way to create a custom CRS without using the GUI of QGIS on Windows? I am trying to create a custom CRS but my GUI seems to be broken. I cannot use the normal way ("...
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0answers
15 views

QGIS 3.4.5 print composer: doesn't print DIN A0

I want to find a way to print a map with a raster layer in greyscale (GeoTIFF) and two vector layers in shp-format. I created a map layout and went to the page properties (right-click on the canvas) ...
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0answers
31 views

PYQGIS QgsAction Does Not Work

I am using QGIS3.4 (built-in Python 3) actions.addAction and trying to open a local photo, with the below code I am able to store the photo path in the feature attribute and created an action, I have ...
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15 views

Starting QGIS 3.4 with own startup.py faults on Mac OSX Catalina

Created file startup.py: from qgis.core import * QgsApplication.setPrefixPath('/Applications/QGIS3.app/Contents/MacOS', True) qgs = QgsApplication([], False) qgs.initQgis() qgs.exitQgis() and saved ...
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20 views

Open QGIS Project in both Linux/Windows

My company has workers that use Windows and Linux to manage a QGIS project. However, when we use the same project created in different operate systems the layers lose file paths. Is there ...
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1answer
16 views

Write layer style .qml as predefined within a gpkg using R

I have this code to export a layer (Pbm) to a gpkg called "Atlas": writeOGR(Pbm, paste0(normalizePath(OutputFolder),'\\', "Atlas.gpkg"),"Atlas", driver="GPKG", encoding = "UTF-8", ...
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0answers
9 views

Sorting Relation_Aggregation Expression Results in QGIS3

I am using a relation aggregation expression to grab a list of inflows from other sewersheds. Some sewersheds take on flows from more sewersheds than others so I approached it through a relation so ...
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0answers
19 views

Why does measurement units return degrees when using PyQgis? [duplicate]

I am using PyQgis to measure some selected line features using distance.measureLength(feature.geometry()) and when I use distance.lengthUnits() I get returned a value of 6 which refers to degrees. My ...
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1answer
27 views

Clip raster by mask layer change the pixels size

I've a raster that have the pixels of this dimensions: x 0.2282548198093489467 m y 0.3594572165075641257 m I need to clip this raster with a vector because I need a raster with the same extensions ...
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0answers
16 views

Outputting layer as table at end of process

I am in the process of migrating some QGIS 2.x processing toolbox script to QGIS 3.x. I have a collection of scripts that helps in the seismic 3D planning and geometry processing. One of the scripts ...
2
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0answers
30 views

QGIS 3.4 - Can't Save Custom Projection [duplicate]

I am having the same issue on QGIS 3.10 or the long term release, 3.4 If I go to Settings > Custom Projection and add a name and parameters, the "OK" button does nothing. I have tried clicking the ...
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1answer
34 views

QGIS 3.4.12 print composer, cm distance

In print composer, I would like to syncronize the scale of the map with the Grid scale. For example, in print composer I am making a map in 1/1000 scale, so I go to grid,and insert "map units" x=100 y=...
1
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1answer
35 views

Why the “shape tools” won't work with a different CRS?

I just used a tool from the "Shape Tools" plugin but the results were nonsense. The CRS of the point layer and my project CRS were EPSG:4326 - WGS 84. Here is an image of the result: The correct ...
1
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1answer
59 views

Creating custom CRS in QGIS

I am trying to define a custom CRS in QGIS 3.4 to work on some data in Central Asia. I want to use the Albers Equal Area Conic but change the parameters so that the transformation works best for my ...
2
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0answers
22 views

Search yields no results in plugins menu

I can't manage to figure out why I can't download any plugins. I have an Internet connection, but it seems like QGIS can't access the online repository of plugins. As an example, I'd like to download ...
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0answers
19 views

QGIS Graticule at Print Layout starting at from 0

I would like to add a graticule with coordinates to my map. However, when I add a new grid and modify it the graticule appears but it always starts at 0 and not from its real value. How could I fix ...
2
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1answer
16 views

Unable to set scale on QgsLayoutItemMap

I have made manually one layout in QGIS 3.10, I access it using PyQGIS and I want to add a new QgsLayoutItemMap. I'm unable to set scale correctly. Does I miss a step? Is it a bug? Are you able to ...
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0answers
10 views

Sharing classes and methods code among processing scripts

I am writing a set of processing scripts for seismic data acquisition (2D and 3D) planning and geometry processing. They are very crude scripts (I'm not a developer) that performs the tasks I meant ...
2
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1answer
50 views

How to display the correct unit of measure in PyQgis?

Within a plugin I am developing I select features and for each line feature selected I get the feature distance using: distance.measureLength(feature.geometry()) I also get the total length at the ...
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0answers
38 views

How to retrieve text from a QLineEdit in a tabifyDockWidget

I've write a plugin that calls a tool when a certain push button in my tabifyDockWidget is clicked. When the comboBox button is clicked it works perfectly carring the comboBox.currentText() to the ...
2
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1answer
42 views

Why does QGIS convert IntegerLists into something strange and how do I process these in PyQGIS?

I have GeoJSON data which has an integer list and I'd like to query that list in QGIS via GUI (select by expression, visualization) and probably later with PyQGIS. The problem is that QGIS recognizes ...
3
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3answers
193 views

PyQGIS using selected layer from a combobox

With PyQGIS 3, I defined a comboBox to list layers from a QGIS project. I want to use the selected one to execute a treatment. I tried comboBox.currentData() class but it doesn't seem to be the good ...
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0answers
27 views

Rotating vector grid in QGIS 3.10 vs 3.8

Just wondering if anyone else has had an issue with vector rotation via the advanced editing tools in 3.10? I have a vertical grid overlaying Vancouver Island that I had tried to rotate using the ...
4
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2answers
76 views

Making curved stroke shape of polygon

I have a lot of polygons representing Forest land use type. Is it possible to style these polygons in such a way like on this picture? Example polygon I have now: So the polygon doesn't have edges, ...
2
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1answer
35 views

Setting label colour based on a field value?

I have created a shapefile with lines which I use to place labels exactly where I want them relative to map features. The shapefile has a field for the name that will appear as the label and also a ...
2
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1answer
22 views

pyqgis create layer from a list of points

I am working with pyqgis in QGIS3 and i want to create a point layer from an intersection beetween a point and a polygon layer. I can identify wich points intersects my polygon layer but i can't use ...
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0answers
14 views

Add python modules so scriptrunner will find them for QGIS on Mac

I am using QGIS 3.10, and Mac OS 10.(14 & 15) This issue relates to recent versions of QGIS for the Mac that are distributed as .dmg. These versions of QGIS bundle their chosen version of Python ...
4
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1answer
74 views

Processing toolbox not working in QGIS 3.4.13

The processing toolbox stopped working in the previous QGIS 3 ltr version I had installed. Now installed 3.4.13 but processing toolbox still not working. I've tried changing the GRASS path without ...
4
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1answer
47 views

How to edit a processing tool in QGIS

Is it possible to make a copy of a tool from the Processing Toolbox in QGIS and make edits to it? As an example, I would like to make a copy of the Import geotagged photos tool and then edit the code ...
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0answers
48 views

Linear extrapolation of points using QGIS

I am currently working with hurricane data from NOAA’s IBTrACS. Each gathered data point is separated by three hours. The points and lines can be found in two different data sets on the IBTrACS ...