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Questions tagged [qgis-3.0]

For questions about Version 3.0 of QGIS

-1
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0answers
37 views

QGIS for beginners [duplicate]

Could anyone suggest tutorials for a beginner in QGIS? I've gone through the ones teaching you how to compile a basic map and such things, now I need something more.
1
vote
1answer
98 views

Open the object attribute dialog for a selected feature with the Python QGIS API

I want to open the attribute dialog programmatically for a selected feature. I need to achieve the same effect as if the user clicks on the "object identify" action ( CTRL + SHIFT + I). I searched the ...
0
votes
1answer
31 views

Extracting point data with PyQGIS? [closed]

How to extract x,y,z values from a point/node in PyQGIS? I am working on QGIS 3.
1
vote
1answer
32 views

Reset canvas match print composer QGIS 3

Is there a way to reset the map canvas to match the layers, or layers and styling from a "locked" print composer window? The lock layers, and lock layer styling buttons in QGIS Print Composer are ...
1
vote
1answer
48 views

Static traffic visualization for certain streets with the help of historical traffic data, in QGIS? [closed]

The goal is to make a static map highlighting certain streets in a city that usually have high traffic (for example, highways and main roads). I am using OpenStreetMap for the city. The streets need ...
2
votes
1answer
187 views

Reason for better save capability of QGIS 3

I have an internal processes meeting with work where I am trying to describe the benefits to migrating to QGIS 3 from QGIS 2. I need to explain the technicalities of how the save option works better ...
0
votes
1answer
48 views

Changing the attribute table view in QGIS 3?

How does one change the Attribute table view on QGIS 3? An initial answer says to use the "Switch to Table view" button but I can't seem to find this button.
3
votes
1answer
33 views

Listing all point items in polygon?

I'm trying to get a list of all points (from a point layer) that can be found in a unique rectangle polygon. Input layer 1: points (address data) Input layer 2: rectangle polygon layer (created with ...
0
votes
0answers
10 views

Inverted polygon not displaying on printout

I'm printing from the layout in QGIS 3.2.2, using Windows 10. The page size is 42x42 inches. I created an inverted polygon to cover up layers that were outside of the main polygon. I printed ...
1
vote
1answer
50 views

Showing OSM source acknowledgment on the map in QGIS?

I am using OpenStreetMap as a base layer via XYZ tiles in QGIS 3.01. I can't seem to find a way of having source acknowledgement appear on the lower right corner of the map. Can somebody point me in ...
1
vote
0answers
119 views

Dissolve with stats plugin does not appear in QGIS 3.0

So far we have tried to: find it in the plugin repository from QGIS, with no luck. install the plugin downloading it from the web QGIS Python Plugins Repository: https://plugins.qgis.org/plugins/...
4
votes
2answers
82 views

Custom scalebar with half-segments in QGIS

I am trying to recreate a scalebar thats part of a norwegian standard (NS3039) in QGIS. QGIS makes these half-segments for negative values (highlighted in red in the picture below 1, but I want ...
1
vote
1answer
88 views

Why a QgsExpression does not evaluate a feature as expected in PyQGIS 3?

When I run following code in QGIS 2.18: layer = iface.activeLayer() expression = QgsExpression( u'"area" > 2e8 AND "area" < 3e8' ) feats = [ feat for feat in layer.getFeatures() ...
1
vote
0answers
61 views

QGIS 3 calculate totals and display on the map

I have recently started using QGIS 3, at a very basic level really, I am displaying radio coverage drive test logs which are in tab delimited format. I have sucessfully imported the file, and written ...
0
votes
0answers
68 views

Alternative of Web App Builder

I'm currently using: QGIS 3.2, OS: Linux (Ubuntu) The Boundless plugin i.e. QGIS web app builder isn't supported on QGIS 3 version I guess. I tried installing it through the zip file method but ...
10
votes
4answers
780 views

Buffering only sides of polygons in QGIS?

My goal is to create a buffer from a polygon. But the edges are the problem. I can't really explain it in words, so I will post a screenshot. That's the way I want it to look. So the goal is, that the ...
1
vote
0answers
47 views

How to recenter extents of my coordinate system in QGIS?

How do I change the extents of a projection of the world so that longitude 90W is centered? I'm working in WGS84. Perhaps I need to add some clarification of my objective. I have a dataset of the ...
9
votes
2answers
182 views

Drawing viewpoint-symbols in QGIS?

I made a viewpoint symbol in QGIS by styling a point to be be a circle and adding some lines that are rotated at different angles, and it ended up like so In a perfect world I would rather this ...
2
votes
2answers
52 views

Merging attributes in QGIS? [closed]

I have a layer with several polygons making up a division together. They all have attributes with population. Is it possible to add up the population in a merge so I don't have to use a calculator ...
0
votes
0answers
48 views

Displaying picture in QGIS 3.X custom form (QT designer)

I have a problem with a function that worked well with QGIS 2.X but not with QGIS 3.X I want to display an image in a form made with QT designer. I followed this: In QtDesigner Add a new QWidget ...
5
votes
1answer
104 views

Creating unique buffer for each set of points separately and in one procedure using QGIS?

How could I create a buffer for each set of points (colour group) separately and in one procedure in QGIS 3? The image below shows a subset of points for buffering.
0
votes
1answer
69 views

How many themes can I create in QGIS?

How many themes in layers box can I create in QGIS 3.0?
2
votes
0answers
38 views

Copy polygons to another layer with different attribute

I am working in QGIS 3.0.2-Girona. I am digitizing images in which there are rocks that can be encrusted, totally or partially, by algae. I want to have a polygon for the rock and one for the algae. ...
0
votes
1answer
36 views

How to set checked “Auto Open Form” in identify results window, programatically?

I want to set check programmatically "Auto Open Form" check box in Identify Results window. Window is here and the check box is at the bottom-right: The Identify Results window is not open at that ...
0
votes
0answers
14 views

Error in executing “Export DXF” from main menu

I have recently found the tool Export DXF that transfers attribute table information along with the geographic location data from a shapefile to a dxf file. However, I have found that sometimes a ...
0
votes
0answers
30 views

Getting LayoutItemLabel from layout QGIS

I'm trying to modify selected layout items in a QGIS Layout using the python consol. I'm using the following code to access the selected items from the layout projectInstance = QgsProject.instance() ...
1
vote
2answers
49 views

Usage of ELSE Conditional Statement in QGIS Field Calculator

I have an issue about how to change some data in a field not affecting unrelated data. I want to replace '(space)' between words in label_geo_ field data by this '_' sign when (if) this sign appears ...
0
votes
0answers
17 views

Issue with qgis 3graphcis

I am using the latest installation of QGIS (3.2) in a Macos Sierra 10.12.6 and I get those graphic issues on the top left of the software (see image). Also when I go to full screen the tool tabs get ...
1
vote
1answer
23 views

Using “Difference” geoprocessing tool on Big Data taking a very long time

I am using QGIS Bonn 3.2.3. I've recently been using the Difference function to calculate a list of points and it is taking a terribly long time. I was wondering if you could point out any obvious ...
2
votes
2answers
259 views

Make polygon circular in QGIS

I have drawn a polygon in a shape-layer, but it's not perfectly circular. Is there a way to either Draw a circular polygon with a given radius (in a shape-layer) Make a polygon into a circle I have ...
1
vote
1answer
122 views

Large Export Issues - QGIS 3.2.2

Still pretty new to GIS, but Ive been working on assembling a map with ~20 vector layers over the past couple of weeks. Its finally to a point where Im ready to export. Ive been experimenting with ...
0
votes
1answer
28 views

Using PyPDF2 in PyQGIS 3!

I use PdfFileMerger from PyPDF2 in a plugin that I want to migrate from qgis 2 to 3 but it seems that this lib doesn't exist in qgis 3 (python 3.6). How I can do this?
1
vote
1answer
98 views

OSM data does not match

I downloaded OSM data for Austria from Geofabrik and converted them with ogr2ogr into a SpatiaLite database so that I could use some Google Maps style sheets I found. Until here, everything worked ...
2
votes
1answer
154 views

Migration plugin from QGIS 2 to QGIS 3: list layers

I am trying to migrate a plugin from QGIS 2 to QGIS 3. This function doesn't work with QGIS 3 : def getLayersByKeyWord(keyword): #retourne une liste de layer res=[] layerMap = ...
0
votes
1answer
66 views

Exporting into Excel file from PyQGIS?

The following code allows me to save a text file with .xls extension in Python. When I open it, I receive the following warning: The file you are trying to open, is in a different format than ...
1
vote
0answers
44 views

QGIS r.clump function not working?

I am trying to follow this course "https://www.youtube.com/watch?v=IfZSyBf6o84", starting from 20:00, and failed to reproduce the clump function based file, as the warning message shows: Anyone have ...
2
votes
0answers
41 views

Changing the Location of Python Expressions QGIS3

I've recently started using QGIS and I've written a few custom functions to use with expressions in the Function Editor (see image below) From what I can find these appear to be saved in: C:\Users\...
2
votes
1answer
86 views

QGIS: I can barely see the labels in layer panel

So, I finally bit the bullet and upgraded to QGIS 3.2.3 Bonn. However, for layers that are not turned on the font is a super light grey in the layer panel and I can barely read it. How can I change ...
6
votes
3answers
158 views

Programmatically changing line lengths in QGIS?

Provided a set of lines with various lengths, I would like to change their lengths (hence, changing their geometry) to a specific value, using their centroid as base point. I have checked the ...
0
votes
0answers
38 views

Combined style-file for shape-points, lines and areas

We have three QGIS Layer Style files. One for shape points, one for shape lines and another for shape polygons, which we load unto our datalayers to make the analyses we create look like they have to. ...
2
votes
1answer
41 views

Arranging GUI elements in QGIS 3 processing model user interface

Using QGIS 3 graphical modeler I created a model with a variety of input parameters (> 10). When starting the model, a nice user interface is generated. But the arrangement of the GUI elements is ...
2
votes
1answer
78 views

Changing Layer CRS Causes Misalignment and Scaling Issues [closed]

Update: My final solution was to re-download the data sets and all my alignment issues were solved. Background: I am working on a personal project overlaying the location of churches/parishes on ...
1
vote
0answers
87 views

How to fix self intersected polygons visually, as well in QGIS?

I have same invalid polygon features because of self intersection. I can make them valid by using fix geometries tool in QGIS 3.2. However I want to show them valid visually also. The feature is valid ...
0
votes
0answers
13 views

How to stop first grouplayer expand when starting qgis

Can i stop QGis to open first grouplayer when i load new project or starting QGis ?? In the project file qgs all layers are expanded=0 but stil it open the first grouplayer.
1
vote
0answers
49 views

QGIS 3 processing script won't show gui when executed from editor

Different from QGIS 2, when I execute a processing script from the Processing Script Editor by pressing the Play-button in QGIS 3 it's GUI is not created. Seems to me that the initAlgorithm() method ...
3
votes
1answer
171 views

Update processing scripts in QGIS 3

When I edit a processing script (QGIS 3.2) with right click > Edit script... in the processing toolbox, save it and then try to execute it by double clicking it in the processing toolbox, the version ...
1
vote
1answer
128 views

Getting and setting the symbol sizes for a graduated layer in QGIS 3

I have a whole set of maps that have graduated colors based on a set ramp and I also like to change the symbol sizes as it makes anomalous areas stand out even more. Id like to change the symbol sizes ...
4
votes
1answer
265 views

Iterate through list of field names and calculate fields with PyQGIS?

I am using QGIS 3.2.1 Bonn 64 bit on Windows 10. I would like to loop through a list of field names and perform calculations on each field. Only the first loop in the iteration performs any ...
1
vote
1answer
72 views

PyQGIS scripts outside of QGIS GUI running processing algorithms from GRASS provider

I'm writing a script that I would like to work outside of QGIS GUI. The script uses the processing algorithm standalone just fine for the native algorithms, however I am experiencing errors when ...
0
votes
0answers
29 views

OSM original and exported polygons don't match

I'm having trouble to understand why polygons from OSM after being both copied and exported to a different layer don't cover their originals. Blue are the new one, with black outline - the original ...