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For questions about Version 3.0 of QGIS

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10 views

QGIS window size problem [duplicate]

I just installed QGIS 3.2 on a new laptop and the map canvas window and map composer windows are half the normal size, with a grey background making up the remainder of the space. How do I make the ...
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0answers
13 views

Size bands now showing correctly in QGIS 3

I'm trying to rank some points in QGIS 3 by size. In the map, they display correctly, but in the layer properties and in the legend the symbols do not display. Is this a bug? Does anybody have any ...
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0answers
27 views

Toggle labels from toolbar in QGIS 3

I recall having a label-toggle button in the toolbar in earlier QGIS (2.x). If the selected layer had labels configured, then clicking this button would toggle their visibility off or on. The labels' ...
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19 views

Changing view page (operating area) size in QGIS?

I can't zoom in on the operating area. The window only shows a partial area. How can I expand the window and fill the remaining space?
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0answers
12 views

QGIS 3 PyQGIS Disable Layer

I am working with QGIS 3 and trying to add Layer in QGIS Canvas using PyQGIS. What i want is that when the layer will be added in QGIS, it should be disabled as there will not be any user control it, ...
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1answer
42 views

Storing the distance between two shapefiles as an attribute in QGIS 3.0?

I have this map of Mexico that is broken down into all of the municipalities. How would I create a variable that has the distance between each municipality and Mexico City?
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1answer
31 views

Distance Matrix with 2 point shapefiles and one street network

I have two point shapefiles (start/destination) and one sort of street network shapefile. I would like a to create a distance matrix from the start-shapefile to the destination points, using the ...
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0answers
18 views

Where to put new tool function and how to call it?

I code a small plugin to get parcels numbers from the canvas to the QPlainTextEdit object in my dockwidget. I found nice piece of code in topic Getting attribute value from vector layer after mouse ...
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25 views

Adding a Tiles/wms? (openStreetMap) layer with python in QGIS

In my QGIS python plugin I want to add a background map (if the user haven't added one), hence I think I missing something in the url for the Tiles/wms service.. (the function returns invalid layer) ...
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0answers
25 views

Detect wfs connection user

I am working with plugin builder. As I can detect the user that belongs to the wfs connection, I just need the username, in order to pass it to the plugin I am developing. The configuration of the ...
1
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1answer
32 views

Adding an empty PostGIS table as a layer in QGIS?

In QGIS 3.2 (and 3.0), when trying to load a PostGIS layer into QGIS using a python function as follows: def create_pg_layer(table,schema,geom_column='geom'): uri = QgsDataSourceUri() # set ...
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1answer
39 views

Error: Algorithm not found with correct processing use

I try to run a simple dissolve algorithm in a standalone Python 3 script. My code is following : from qgis.core import QgsVectorLayer import processing from processing.core.Processing import ...
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0answers
30 views

How to use QGIS plugins functionality in standalone application

I'm new to QGIS 3 Library to develop standalone map application in qt4, C++ language. I was wondering if there is any way that I can use QGIS plugins such as Advanced viewshed analysis, Contour plugin ...
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24 views

Using Python to set text for a label in a QGIS3 print layout label

I am able to assign a QGIS 3.2 print layout label item to a Python variable using: MyMapLabel = MyPrintLayoutObject.itemById('MyLabelName') Which is all well and good but I need to be able to change ...
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0answers
15 views

Save style in database (spatialite) disappeared

I want to save a style to database (Spatialite) but when I use save style in Qgis 3.0 I am not getting this option in the drop down menu. So how do I save my styles to database in Qgis 3.0? It used ...
1
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1answer
49 views

Downloading Map Tiles from Griffiths Valuation of Northern Ireland?

I would like to download map tiles of Northern Ireland associated with Griffiths Valuation of Ireland in 1867. These maps have details of property leased by individuals, including farm fields and ...
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1answer
15 views

QGIS 3.2 - number field display in attribute table in american format

Since upgrading to QGIS 3.2.0 the int and numeric formatted fields are displaying in the attribute table with a comma added for numbers of more than 3 digits (e.g. 12,345 instead of 12345). It looks ...
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1answer
38 views

QGIS API 3.2 and PyQT5 in Ubuntu Fails: Native Qt signal is not callable

I'm trying to migrate from QGIS API 2.18 to 3.2 in Ubuntu18. Several changes are made, including the update from PyQT4 to PyQT5. This is the very beginning of my code: from qgis.core import ...
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1answer
21 views

Field editor in QGIS 3.0 no Text edition button

I used QGIS 2.18 and now I use QGIS 3.0 under Windows 10 in Spanish versions. In the field editor in version 2.18 each field had his button "Text edition" but in version 3.0 that button doesn't ...
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0answers
14 views

Heatmap Tool in QGIS v3.0 not working

I am trying to use the Heatmap tool in QGIS v3.0 but keep getting the following error: I have tried installing the plugin - but it doesn't appear in the list. I can't find the option under Processing ...
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0answers
21 views

Create axes given origin and angle [closed]

I have a QgsPoint. One of the attributes of this point is 'heading', a number from 0 to 359 indicating an angle. I want to create two lines going though this point, one in the direction of this ...
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0answers
15 views

Altered Minimum Bounding Box Algorithm [duplicate]

I'm trying to create an algorithm similar to minimum bounding box (though it may end up looking nothing like it). In this case the angle will be passed as a parameter and given the angle I need the ...
1
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1answer
32 views

Correct way to delete a field, add a field and update attributes in pyqgis

I am working on a script that runs a model and then appends the result to a spatialite layer. The model runs zonal statistics using 4 different rasters and appends them to the attribute table of a ...
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0answers
12 views

Cannot run external scripts with QGIS 3.2 on Mac OS X 10.12

I am trying to move some automation out of the GUI and into some external python scripts, and I am having a challenge getting a script to run in Terminal. I have a fully functioning install of QGIS 3....
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0answers
45 views

QGIS 3.2: Processing toolbox tools from SAGA never run

I am having major issues in getting tools to run from the toolbox in version 3.2. In essence all but very simple algorithms like 'Split RGB' return errors and do not run. I cannot get any openCV or ...
2
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1answer
26 views

How to call “Clip Raster by Mask Layer” tool using QGIS console? (gdal:cliprasterbymasklayer)

I execute the followng code in QGIS 3.2.1 console, but Clip Raster by Mask Layer tool doesn't work - output file is not created. Here is QGIS console output: None # perhaps this None appears as a ...
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1answer
38 views

Putting photos on point using QGIS 3.0? [duplicate]

I need to be able to bring the pictures as points and then be able to click at a certain point and an image pops up. I added a column for images label as pic. How can I show that image on the point?
2
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2answers
53 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 ...
1
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1answer
41 views

Polygon area calculation discrepancies

I use the following code to calculate the areas of a multi-polygon shapefile. However, to validate these results, I calculate the polygon’ areas directly in table attribute by creating a new field and ...
3
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0answers
37 views

QGIS 3.0.3 (and 3.2.0) crashes on start. Ubuntu 16.04, conda environment

I am trying to QGIS in a conda environment, python 3.6.5, conda 4.5.8, Ubuntu 16.04 Xenial. It crashes upon start-up without even loading all the way. I have tried both QGIS 3.0.3 and 3.2.0 (3.2.0 is ...
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0answers
50 views

Getting solid shape of dam lake in 3D by using QGIS?

I am working on a plugin. I will get a raster map of a dam lake for instance. When load that map I want to get a 3D model which fills the lake entirely. Then I will divide the lake on horizontal view ...
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0answers
36 views

Creating heat map with fixed max color value in QGIS?

I am trying to create a heat map using raster data in QGIS 3.0. I have made them previously in ArcGIS pretty easily, but I am having difficulties in QGIS. The difficulty I am having is setting a fixed ...
3
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1answer
123 views

Real centroid plugin QGIS3

I am looking to use realcentroid where I'm assuming it puts all points within the polygons rather than the tool in QGIS Vector -> geom -> centroid tool, which in my result some bendier polygons have ...
1
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2answers
49 views

Invalid geometries in QGIS 3 seems to be more prevalent than QGIS 2

I have a large polygon vector data set containing approximately 10,000 rows of data. I have used this data to run specific tasks in the QGIS 2 series (many of the Geoprocessing tools) with no issue of ...
1
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1answer
78 views

How to query 1 feature of each category using QGIS (SQL like) expression language?

I use QGIS 3.2 to select features in a shapefile. Lets say I have shapefile which contain 100 features and have such fields: Class with possible values A,B,C. ID with possible integer values 0, 1, 2, ...
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1answer
39 views

QGIS 3.0: Naming layers for saving in GeoPackages programmatically

I have problems to save a vectorlayer at QGIS 3.0 with his original name in a GeoPackage. canvas = qgis.utils.iface.mapCanvas() layer = canvas.currentLayer() writer = QgsVectorFileWriter....
1
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2answers
109 views

Cannot create layer because “unable to open database file” in QGIS 3.2.0?

I'm brand new to QGIS but 10+ years ago I was adept with ArcGIS. I installed 3.2.0 just a few days ago and all went well at first. I located/downloaded/imported the data I want and added a field to ...
1
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0answers
51 views

Editing Layout-Items after loading a QPT-Template in QGIS 3 with Python

I am facing a problem with the new Layout API while implementing a plugin for QGIS 3. Starting point is a layout template in qpt-Format, which contains different elements like (attribute) tables, map, ...
1
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2answers
26 views

QGIS - Layer style categorizing insert missing values

In QGIS Bonn, when styling my layer to use the categorize option, I want to have all values within a range, for instance, 0 to 50000. I am using the data from a CSV that has information about ...
2
votes
1answer
60 views

Seeking QGIS 3.0 ways to create browser based 3D scenes like qgis2threejs plugin does?

I want to create a browser-based 3D scenes and use Github to share it. However, the qgis2threejs plugin is not available in QGIS 3. Is there any alternative way to create similar browser-based 3D ...
1
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1answer
38 views

How to fill fields with layer name in PyQGIS

I have hundreds of shapefiles that I have added to a QGIS project. I am using QGIS 3.0.0. I have created a new text field for each of them named 'Enumertr' in PyQGIS and I need to populate this field ...
3
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1answer
59 views

QGIS 3 does not load default styles from spatialite (defined in QGIS 2.18)

I have a set of styles stored in a spatialite db with QGIS 2.18, the layer_styles table looks like this: Adding a layer in QGIS 2.18 loads the style set as default (waters light blue, categorized): ...
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0answers
19 views

Make QgsVectorLayer().getFeatures() ignore an existing filter

When retrieving features from a layer with PyQGIS by sth. like feat = [f for f in my_lyr.getFeatures('"road_name" = \'myroad\'')] the resulting feat list is empty in cases where a filter is applied ...
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0answers
198 views

Plug in manager not showing OpenLayers Plug in - QGIS 3.2

I have installed QGIS 3.2, and cannot find the OpenLayers Plug-in. Is the OpenLayers Plug-in no longer supported?
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0answers
17 views

Print to PDF in QGIS 3.0 from layout cuts off a strip of the bottom and right hand sides

As per the title. It happens every time I export it through print to pdf. Doesn't matter if I choose "microsoft print to pdf" or "adobe pdf". My map is within the canvas dimensions. When I select ...
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0answers
89 views

Error Heatmap plugging QGIS 3.2.0

My questions is about heatmap plugging in QGIS 3.2.0 I have my data in CRTM05 projection, it´s a metric projection to Costa Rica based in WGS84 Datum. When I try to run the Heatmap plugin, the ...
1
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0answers
25 views

QtDesigner shipped with QGIS 3 doesn't show svg's in resources

In the QtDesigner shipped with QGIS 3 svg's and jpg's are not shown in the Resources window nor as icons on widgets: QtDesigner from QGIS 3.2: svg's example jpg's example QtDesigner from QGIS 2.18 ...
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1answer
31 views

Find QGIS 3 plugin folder location with PyQGIS

Background of my question: I would like to figure out the version of a plugin ('my_plugin'), in PyQGIS 2 like: from qgis.utils import findPlugins import os plugins = list(findPlugins('C:\Users\me\....
1
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1answer
47 views

Passing “self” when calling functions in modules from other modules using PyQGIS?

I'm building a QGIS 3.0 plugin and trying to organise my code into several files. I have three files - a main python script and two other scripts stored in a subfolder. Excerpts provided below: \...
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0answers
20 views

Reduce or heighten a DTM with overlaying polygons

I am using QGIS 3.01. I have a DTM over a historic area. There has been done archaeological surveys there, which suggest that the ground was several meteres below todays surface many hundred years ...