Geographic Information Systems

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QGIS is a cross-platform GIS application licensed under the GNU General Public License.

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37 views

Finding regularly intervalled GPS positions between two known GPS points

I have been trawling for a solution for a while now, and either I cant find the correct solution or I'm not quite getting my search right. I have some GPS points from a ship track that are collected ...
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1answer
59 views

eVis plugin not showing in QGIS 3.16.3

I'm trying to use the eVis plugin in QGIS 3.16.3 to display geotagged photos (as I have in the past without difficulty), but the plugin has totally disappeared. Not only can't I find it as an icon or ...
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0answers
19 views

Precise Projection output in image files

A friend is having problems with output of a projection in QGIS. The problem statement is: How to output a projection from upper left corner being Pacific/Guam, lower right corner New Caledonia/Noumea ...
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0answers
37 views

Removing number of special characters at same time using QGIS [duplicate]

I have a file with number of special characters in it. I can easily replace that in ArcGIS by building a query. How can I replace them at the same time in QGIS?
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1answer
64 views

Elevation data for settlements

I'm new to QGIS, and I'm trying to plot settlements on a map with their elevation data (using Openstreetmap). Problem is, I find most of the villages/ towns have their 'ele' data missing in the ...
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1answer
85 views

Is topology stored explicitely in vector layers or is it derived from stored geometry information?

In vector layers, different types of information are stored like: Geoemtry Attribute data Meta data (like filename, projection etc.) Spatial indices However, what about topology? Is it an explicit ...
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1answer
32 views

Problems with cleaning the topology of a shapefile using GRASS tools and snapping tools

I have a shapefile with almost 1000 polygons (each polygon representing a farm). There are a lot of topological errors (gaps/slivers and overlaps between polygons). Below is a "zoomed in" ...
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1answer
47 views

Image not visible in a webmap from QGIS2WEB

I have got a map created in QGIS where there are some pictures linked to a different polylines. Those pictures are stored in an image hosting, therefore I got a field in the polyline´s attribute table ...
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0answers
15 views

SVG created by QGIS Profile tool won't scale to include the vertical units!

I exported an svg image from the QGIS Profile tool but when I go to use it in a Picture on a map layout it will not scale to show both the X and Y units. It's like they are not considered as part of ...
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2answers
45 views

Multiple base map in Qfield?

Is it possible to load 2 base maps in Qfield (both of the 2 rasters are in geopackage format), and choose wich one I want to see and maybe switch during the field work ? I tried with the map themes ...
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0answers
24 views

Calculating area-weighted mean of a raster in QGIS

I am working with a global raster dataset (WGS84 projection) where the value of each grid cell equals a rate (g N m-2 yr-1) (r_rate). I would like to calculate the average rate (i) for the whole ...
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1answer
26 views

QGIS Union: Could not add feature with geometry type GeometryCollection to layer of type MultiPolygon

I overlay several Shapefile layers with Vector > Geoprocessing Tools > Union in QGIS. The first five layers do work. However, when I'm trying to add another layer I receive the following error ...
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0answers
20 views

Batch processing - Translate - JPEG compression parameters

How can I configure the batch processor to enable JPEG compression? Just like in the "Run as single process..." I guess I need to add instructions "Additional command-line parameters&...
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0answers
34 views

XYZ tile not rendering in QGIS 3.16

I am using QGIS 3.16 I have created XYZ tile connections according to all the possible sources & methods that I could find on gis stackexchange, github, etc But when I load any of the XYZ tile on ...
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0answers
21 views

Quick OSM request returns a layer which does not match OSM in QGIS

I made this request from quick osm [timeout:2500] [maxsize:2000000000]; area[admin_level='6'][ref='90']->.area; rel(pivot.area)->.rel; ( node[highway](area.area); node[highway](r.rel); way[...
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1answer
62 views

Can we use QGIS as commercial use?

Do i need to purchase the QGIS license for commercial use? Can i use the QGIS commercially in our project? https://qgisenterprise.com/en/offering/packages/ I found the few variants of QGIS but the ...
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0answers
28 views

Running script within QGIS action crashes

I am running the following script (got it from QTDesigner and just slightly modified it) in a QGIS action which makes it crash altough the script runs totally fine within sublime for example. Any ...
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0answers
18 views

Difficulty downloading QGIS on Apple

Every time I download QGIS on my MacBook Air and try to open the application I receive a message that reads, "QGIS can't be opened because Apple cannot check it for malicious software," ...
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2answers
36 views

Offset raster boundary by elevation

I've been given a raster with flood elevation limits along a river, it's not a constant flood level so elevations range by ~35m. I need to do an analysis of the impacts if these elevations were 2m ...
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4answers
92 views

Merge several polygons/features into one continuous area not working

I am using QGIS version 3.10. I have a farm boundaries layer (https://drive.google.com/drive/folders/1xYZmSboM75GACCWQyx-06wZ3EdHBcMrM?usp=sharing), and want to merge certain adjacent polygons into ...
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0answers
30 views

``Qt: QUndoStack::endMacro(): no matching beginMacro()`` error on PyQGIS script

I am working on a QGIS plugin that allows redrawing a selected feature without losing its original attributes. The plugin works properly and the process ends well but I am receiving a QT error that I ...
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0answers
29 views

Can't calculate raster using QGIS

So I'm new to QGIS (2 days) but have spent HOURS on it everyday trying to learn it to process raw SRTM data make 3D relief maps on another software, so I can work my way around it but can't really do ...
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0answers
42 views

QGIS transformation local coordinate system to UTM35

I am creating a geo database for an archaeological excavation. We want to put data from a local system and from UTM35 in the same QGIS-project. I have Ground Control Points and I calculated ...
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1answer
36 views

How to filter dropdown options in QGIS attribute table?

I have the following layer table Prim | Secondary |Tertiary Apple | Apple Pen | Apple Pen White Apple | Apple Pen | Apple Pen Red Apple | Apple Phone | Apple Phone Black Apple | ...
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1answer
67 views

Using PyQt in PyQGIS inside QGIS 3.16

This code Using PyQt5 extracted from http://www.tutorialspoint.com does not work when I add it in a script in the console of QGIS 3.16. Can you enlighten me on this subject? import sys from PyQt5 ...
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1answer
47 views

Extract raster properties and use them in QGIS graphical model

I would like to generate a tool that reclassifies rasters in 10 classes with equal intervals. Since QGIS reclassifies tools does not allow to automatically create classes with such methods, I was ...
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0answers
23 views

The proportion of population covered by created isochrones in QGIS

I created isochrones using Iso-Area as polygons algorithm is QGIS. I would like to calculate the proportion of the population covered by the created isochrones. Is there any tool in QGIS to do this?
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1answer
27 views

Line still appearing but not existing in the metadata of a shapefile

For a project, I had to merge the cells of a grid to upscale it. It was possible to merge all I wanted but there is kind of a displaying problem: there is this line which appears visualy but that is ...
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2answers
27 views

Deleting data by location using another shapefile

I have two shapefiles: one is main file and another is a part divided (manually by selecting) from the main file. Now i want to delete the divided part from the main file with the help of divided part....
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0answers
22 views

Finding and deleting overlapping polygons using QGIS

I have generated these (green) polygons in ArcMap 10.5.1 by: import XY data > buffer 5 m > minimum bounding geometry (plus a couple of other steps). self-intersect of polygons The screenshot is ...
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0answers
31 views

Unusual QGI3S “Exception: Unkowns”

I'm trying to process some OSM data extracted via Osmium. I've managed to process some of my smaller datasets, but as I've begun working on the bigger ones, I'm receiving some odd errors. Specifically,...
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0answers
18 views

Display DrillHole locations in QGIS from SQL Server database source

I'm using QGIS 3.10.9, and I want to be able to display some drill hole data from my source database, which is on a SQL server. (I've been able to export the data into CSV format and display the data ...
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0answers
20 views

Connection database failed in Qfield

I'd like to take a test about the connection to the database in QField in my smartphone Android but it failed; so I cannot view the layer Postgis on the map. The database Postgresql is installed and ...
2
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1answer
32 views

Exporting a group of raster layer bounds from QGIS to a GeoJSON

I have a QGIS project with a lot of raster layers; and I want to build a Mapbox map based on this project; that would display those images on a website's map. I need a way to export a group of raster ...
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0answers
22 views

QGIS - Network join issue with cost allocation using OSM dataset

I've been trying to create a cost allocation map, using the v.net.alloc tool on QGIS with Grass. Some of the results don't connect to the network fully, even though they should in real life. This has ...
1
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1answer
32 views

QGIS Processing Modeler not showing algorithms anymore

I use QGIS 3.4 on Linux Mint 18.1 and have happily created models once I came to know about this awesome feature. But some days ago the algorithms disappeared. If I right click in processing modeler I ...
1
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1answer
37 views

Batch processing error in QGIS

I get a Python error when I run any plugins as batch processing in QGIS 3.6.3. The problem does not solve if I change layers. Any idea how to solve it? The error I get is: WARNING Traceback (most ...
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1answer
35 views

QWC2 - Projects not available as themes

We have a folder accessible by QGIS server containing some projects to be served as WMS: Projects are available in the qwc admin qui when creating a new theme: There is a theme for each project: I ...
1
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1answer
58 views

Changing number of decimal places of a String variable within a Vector Layer using PyQGIS

I have earthquake data and within the data, there are magnitude, longitude and latitude values. However, these values have around 6/7 decimal places but I would like to only have 2 decimal places for ...
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1answer
26 views

QGIS custom Python expressions not loading on startup

My custom Python expressions are not loading at startup and I dont know why. Its a real pain because I have virtual layers depending on those expressions, so after I load them I have to manually ...
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0answers
17 views

QGIS: Exporting/saving extents of WMS raster layer in a batch process

In QGIS is it possible to run: Export -> Save As as a batch command? I have WMS-raster layers from which I'd like to extract certain extents (based on quite a number of features from a vector layer)...
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1answer
34 views

How to calculate mean of GPS data assigned to 30 m segment in QGIS?

I have collected some temperature data from a Google Car dataset with each data having Lat/Lon and temperature values. The data is stored in CSV file. I already fixed the GPS lat/lon by using "...
2
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1answer
63 views

Building exaggerated elevation profiles from VRT DEM in QGIS

I have this little challenge, where I need to build an elevation profile from a VRT DEM mosaic of +5000 TIF files. All Z-values should be exaggerated by factor 10 as it's common in road construction. ...
2
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5answers
222 views

Changing style of points while moving them in QGIS

I have 1000 points in QGIS. I want to move them one by one and I want to know which of those I have already moved. I want to change style of point that I moved before. How can I do that?
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1answer
34 views

How to set image as background for a shapefile polygon using QGIS

I would like to change the background of a polygon to an image using QGIS. Under Symbology, there is an option for Raster Fill but the .jpg image is so zoomed in you cannot see it. Is there a way to ...
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0answers
21 views

QGIS georeference a Mesh layer with wind vectors?

I have an .nc file with u and v components to create a map of wind speed and direction. When I add the layer as a mesh in QGIS, I am able to get the arrow vectors correctly (image below), however, the ...
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1answer
42 views

Display QGIS Temporal Controller widget within custom plugin widget

I am building a QGIS-Plugin retrieving time-series raster data from several sources, which is then supposed to be visualized (so far separately and manually) via the Temporal Controller widget, added ...
1
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1answer
42 views

How to convert points to polygons

I have a csv file with the positions (x and y) outlining multiple complex polygons. Each point is numbered in a separate field and each polygon is numbered in a separate field. I can load those points ...
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0answers
39 views

Sharing and editing data remotely in QGIS

I have a colleague who has some data in his server (Geopackage and some layers). Is there any way I can access from my QGIS project remote from my home to this data in his PC for editing and running ...
1
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1answer
29 views

Using themes in print layout in QGIS

I can't work out how to create a print layout directly from a map theme - even though the QGIS 3.10 manual says "All configured themes are also accessible in the print layout, allowing you to ...

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