Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
35,830
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QGIS Expression with multiple IS NOT filters
I would like to select features using an expression. I have one field with +-100 different values. I would like to select all values except for two. Something like this:
"FIELD" is NOT ( '...
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3
votes
1
answer
47
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Installing QGIS with ECW support on ubuntu 20.04
I know there are similar questions here, but I've tried every answer and every tutorial I could find, and I still can't open ECW with QGIS (and I kind of broke my qgis install? When I try to install ...
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16
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Relinking CSV files to a .qgz project shared with me
A friend sent me a .qgz file for a project we're working on. When I opened it, it threw up the 'handle bad layers' dialogue.
I updated the filepaths to the CSVs, and they show in the legend with a ...
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19
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Why do I get this error when I run Orfeo Tool Box (OTB) on QGIS? 'ERROR: Missing mandatory parameter'
Why do I get this error when I run Orfeo Tool Box (OTB) on QGIS? 'ERROR: Missing mandatory parameter'
The OTB 8.0.0 version was installed and QGIS was tested with various versions, including 3.22, 3....
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26
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QGIS Contour Vectors to Raster
I'm wanting to create a DEM from vector contours but whatever tool I use, it fails to identify the sea level contour at elevation 0.
I have tried via GRASS v.to.r, QGIS tool Vector to Raster and QGIS ...
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0
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15
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Unable to update field programmatically with related aggregate formula
I have some layer relations and would like to use pyqgis for QGIS 3.22 to automatically calculate the relation_aggregate function. This is what I have in my plugin, but this expression returns None ...
- 2,035
2
votes
1
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77
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How to extend a line to Intersect another line
I've received shapefiles for import into a pipeline modeling program. One of the issues I have is that after the shapefiles are imported, close examination shows that pipelines that should have ...
- 41
3
votes
1
answer
77
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Appropriating ID for all lines inside polygon in QGIS
I have 12 Polygons with a lot of lines in every Polygon. The Polygon have each its own "ID". I would like to add the "ID" of the polygon to the lines it is containing.
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1
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34
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Get WMS data using input point layer and store them in QGIS
When I click on a WMS layer using the "Identify" tool, a pop-up window with some data opens.
Can I store these data in a point layer along with the clicked coordinates?
Can I do this ...
- 95
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1
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31
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Rasterize a vector layer where pixels just need to include a vector inside, not necessarily on the center
QGIS(3.22) I'm trying to compare a vector layer to a raster layer by rasterizing the layer to the same pixel size as the raster and then using raster calculator. I just want to know which pixels in ...
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2
votes
2
answers
71
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Generating high resolution MBTiles in QGIS
Is it option to generate MBTiles file in high resolution (512x512 / 192DPI) in QGIS?
Generate XYZ tiles (Directory) tool allows to create high resolution tiles, but in Generate XYZ tiles (MBTiles) ...
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1
answer
46
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Removing overlapping areas
I have two maps, one with critically endangered mammals and one of current strict nature reserves. As a small part of a project I want to have a map showing the areas with critically endangered ...
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4
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2
answers
195
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Geopackage in QGIS: Search and replace in all attribute fields at once
The context
I have a Geopackage file opened in QGIS. It was created by importing a CSV file. However, when importing, something regarding encoding went wrong: I have several special characters like ...
- 40k
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43
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Displaying a CSV layer and a .shp layer in the same project
I'm a newbie to GIS and particularly to QGIS. I am using QGIS 3.22.5 on MacOS 12.3.1 Monterey.
I want my project to display two layers. One layer is sourced from a CSV delimited text file. The other ...
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3
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0
answers
134
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case statement two string fields interacting
I have situation where the values from two fields (both strings) interact to create the value of a third (also a string). This is from a simple flowchart.
I've tried using the CASE statement but I can'...
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40
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QGIS Extracting Z-Values from vertex on line
I am trying to extract Z-values which have been draped from a raster DEM. I would like to access the individual vertex height values as shown in the image below preferrably in the field calculator
So ...
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16
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Set New Master Authentication Password Greyed Out
I'm trying to use a plugin in QGIS that requires a master authentication to work. I follow the prompts to add one, but once I have filled out both required inputs I can't add it. The "ok" ...
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2
votes
1
answer
42
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Converting .arc to .tif (raster) in QGIS
I got this rainfall data from the Australian Bureau of Meteorology, but it comes in this .arc format which I can't open in QGIS.
After a little bit of googling, I found some relevant instructions for ...
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63
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Find a shortest path from a set of screen coordinates with QGIS
I have a set of screen coordinates whose x axis increase from left to right, and the y axis increase from top to bottom.
Example:
points = x1,y1;x2,y2;x3,y3;x4,y4........
The coordinates are just a ...
- 1,007
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37
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gpx data shows additional lines in QGIS (using GPS Tools)
I created several shapefiles two years ago (lines, MultiLineString, CRS 25833) in QGIS 3.4. standalone. Operating System: Windows 10.
Now, I converted the shapefiles into gpx files (merged the data ...
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2
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0
answers
28
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QGIS (or Pelias): geocode PHI locally, not with a web service
I have protected health information (PHI) and need to geocode locally, not using a web service (a HIPAA violation). I used to do this with ArcGIS, but my license has expired, and I would like to move ...
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votes
1
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45
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QGIS: How to resize a group of polygons?
I was drawing polygons in the wrong CRS so I set layer CRS to the correct one. My polygons moved to another location and also changed the scale. I was able to move them to the correct location, but I ...
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votes
2
answers
62
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QGIS: configure Attributes Form for calculations
I use Qfield to collect field data and I organized all tabs with Attribute Form.
One of the data is to count trees and to multiply the number by 3,27. Everytime I need to use the calculator and write ...
- 53
0
votes
0
answers
41
views
Retaining NaN values in rasterio read
I am attempting to import a GeoTiff mask in which pixels of interest have the value 1, and off-target pixels are Nan using Rasterio. When viewed in QGIS and with plt.show(), off target pixels are ...
- 61
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14
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QGIS: I changed layer CRS and now the scale is much smaller [duplicate]
I was drawing polygons over satellite imagery and after I finished I realized that I set my CRS wrong when creating that layer. I changed Layer CRS to the correct one and all my polygons moved to a ...
- 1
0
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0
answers
21
views
Defining non-color channels as ExtraSamples
I run a PYQGIS script to calculate mean and stdev of an area for one specific raster-band.
processing.run('native:zonalstatisticsfb',{ 'COLUMN_PREFIX' : '_', 'INPUT' : '/Users/pugliesipc/Desktop/...
- 105
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0
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22
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Approaches to distinguish bare soil from artificial soil in an urban context with Pleiades imagery?
My colleagues and I are trying to improve an existing landcover map by improving the distinction between bare soils and artificial soils (e.g. concrete, asphalt). We need a good detection of bare ...
- 101
2
votes
1
answer
31
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Group by unique value then count number of elements then list them
In QGIS3+ Field Calculator I am trying to group features by unique values in field 1 then assign a number (no matter the order) from 1 to n (n=number of elements grouped for each unique value in field ...
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1
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40
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Skiable upslope area of specific point on DEM using QGIS
I am looking for a way to determine the area above a point that can be reached by only walking up or horizontally.
Or in a bit more technical terms, I am looking for an algorithm that starts a ...
- 103
3
votes
1
answer
79
views
Using relations
I am using QGIS, version 3.24.0. I have a shapefile called "Map_CorrectionDEF", uniquely identify by fields "GID" and "unitcode". It is a grid cell, in which the field &...
- 445
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votes
4
answers
118
views
Removing file type from attribute table in QGIS
I imported a shapefile that contains track plots of SGY files into QGIS, and I would like to remove '.sgy' from the file names in the attribute table.
In the image, I've highlighted the section of ...
- 51
2
votes
1
answer
53
views
What is the QGIS installation type and OSGeo4W?
There are standalone last release and long term release among QGIS installation types on the QGIS homepage. However, there is one more OSGeo4W network installation file. What is this? Do I have to ...
- 367
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0
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19
views
TIN interpolation in graphical modeler
I am creating a new script in graphical modeler. I have an input which is « vector field » as point.
But when I use « TIN interpolation », I’m not able to select an « input of the model ». I can only ...
- 600
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vote
2
answers
45
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Qgis- Merging datasets of similar data without losing attributes
I'm looking for advice on how to compile some datasets that each have a different set of attributes.
Each dataset is point data, recorded in one of the two coordinate systems that have been used ...
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30
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How can I add features (points) to my byte (eight bit unsigned integer) in QGIS?
I have a series of data (in Byte - eight bit format) with PDF as GDAL (Geospatial Data Abstraction Library) Driver. My goal is to add point features to it using QGIS, however so far I haven't been ...
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31
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Layouts and reports
I am working with qgis for 1 year now and start to be familiar with "layouts". I have just discover the "report", and undestood that reports are very useful for automation of ...
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18
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How to keep roadnetwork attributes by cutting it to a service area in QGIS?
I extracted a road network including attributes (e.g., categorization of different types of highways) using QuickOSM.
My goal is to cut this original road network to a 50km drivable radius from a ...
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45
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Combining OSM data with non-opensouce data
Can I use OSM data and combine it with non-opensource data for commercial usage (in this case: an expert report)?
Example:
A picture in the report is showing an OSM basemap and data I calculated ...
- 301
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22
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QGIS exit when cleaning project
I've a fresh Debian Bullseye installed (11).
Installation context
Following instructions given here, I've:
Added gpgkey for qgis.org package repository
Added line deb https://qgis.org/debian bullseye ...
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7
votes
2
answers
135
views
Selecting items in the attribute column based on items of the other layer in QGIS
I have the items in my data attribute table, which were selected. What I want to do is make the object with the same value to be selected in the attribute table, which belongs to another layer. In ...
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44
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Import bulk geotagged images stored in web drive using table and convert this link into points
In the Excel sheet added. one column includes rows of links to geotagged images stored in webdrive. Is it possible to import from these links and convert it into point polygons?
When the points are ...
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27
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How to enable QGIS plugins from command line?
I was able write a test plugin and install it to QGIS (ver 3.24, Ubuntu 20.04 LTS). The plugin shows up in the dialogbox from the Plugins -> Manage and Install plugins... menu. It is shown under ...
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25
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One label with different fonts
I managed to have a decent result and I am seeking a better way to do it. Please see the image below.
So far, to achieve the result in the image, I have tried:
Rule-based labeling: It's basically two ...
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vote
1
answer
50
views
Locking a WMS layer in QGIS
When I switch between layout view and print composer view, the generation of my WMS layer appears to change, specifically, the text is barely readable. I assume the call for the WMS layer is a larger ...
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vote
1
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48
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QGIS Graphical Modeler PostgreSQL Execute and Load SQL
I have a QGIS graphical model workflow that I would like to be able to use with a connected PostGIS database. I am able to export the layers into the database and associated schema, but when I try ...
- 129
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20
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Automated way to offset overlapping lines of single layer using QGIS [duplicate]
I've got a Line (MultiLineString) layer with 38 features representing the routes of public transport. They are overlapping on several segments of the road network. I'd like to offset the lines on the ...
2
votes
1
answer
121
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Problem joining multiple matching rows from non-geometry CSV file
I am using QGIS 3.24.0. I have a shapefile, called "Map_CorrectionDEF, in which one of the fields is "unitcode". On the other hand, I have a CSV file, called crop_main (no geometry), in ...
- 445
0
votes
2
answers
85
views
QField imported project location on Android
Using Qfield 2.0.14 on Android 12.
I manually transferred a QField project to my phone. I opened QField and used "Import Project from Folder". I have edited the project and can see the ...
- 826
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30
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QGIS Handling Heatmap Data Range
I have a grid of hexagons with data (ranging between 0 and 1) and, using the centroids of the hexagons as a base, I would like to visualise the data as a heatmap.
On the technical side, this works ...
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31
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QGIS Rasters in same CRS misaligned
I am trying to compare these 3 raster layers of Europe (black & white .tif format rasters) and even though they should all be in the same CRS (EPSG:3035), they do not fit on top of each other.
...
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