Questions tagged [qgis]

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

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Bounding Box — Understanding (setting) Unit of Measurement in QGIS

QGIS Version 3.4 My initial problem (width and depth of parcel polygons) was solved by this post: However, when I run the process the Units of Measurement are unclear. (see below) Moreover, I want ...
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1answer
13 views

“Wrong or missing parameter value: Input layers”

I get this error message when I try p. ex. merge layers or package layers (processing) into geopackage. When I set files from a directory I don't have this problem. Am I missing some configuration? ...
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7 views

QtDesigner is not starting for qgis bat file

The qt-designer.bat file did not launch the QtDesigner. I have tried the file available with OSGeo4W64 installation but the qt-designer did not starts.I also try to start the qtdesigner from the ...
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11 views

QGIS geometry generator - chainage nodes and labels along line at ellipsoidical distance

All points along line solution proposed in other question or plugin or processing toolbox use projected distance and not ellipsoidal. I work with very long lines and is quite important that the ...
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1answer
16 views

SAGA difference tool in QGIS

I am using QGIS 3.4 Madeira. I want to use difference tool from SAGA from the processing tool box since my data has some invalid geometries and want to fix the issue later after using difference tool ...
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Can Project Home variable be used to save default outputs of QGIS graphical modeler

Is it possible to use the @project_home variable in QGIS to set a default file path location for an output in the graphical modeler? Ideally I would like the default to be the project home folder ...
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QGIS 3 shows and saves raw default-values from spatialite-tables

QGIS shows default values from sqlite tables as string in the edit-form when i try to create a new row. After save, the raw default values are stored in the table. How can i edit in QGIS LTR 3.4.7 a ...
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9 views

Developing QT application with QGIS

I want to develop C++ QT(widget or quick) application which uses QGIS. However, i could not find any resources about how to merge each other. Can you help me? Link, method, example etc. will be ...
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7 views

Adding a Virtual Layer queried from a SQL Server View in QGIS project

I would like to add a virtual layer in a QGIS project that is defined by a query. It is sourced from a View (no geometry), which is then joined to a spatial layer for the geometry. The View and ...
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1answer
20 views

Obtain slope and aspect for points in QGIS

I'm new to QGIS. I have GPS points uploaded to QGIS and a ⅓ arc-second DEM (USGS) of the area. I'd like to generate slope and aspect data for each point. What is the best way to do this? The point ...
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12 views

How do you import GEE python coordinate data into QGIS?

I have a .csv file with data and coordinates for that data in GeoJSON format: {"geodesic":false,"type":"Polygon","coordinates":[[[-76.24486906575804,39.72835276629949],[-76.2445995711728,39....
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22 views

Projection to create a grid in km

I am trying to create a 1km2 grid of Kenya but I'm struggling. I have changed the projection to EPSG:32337 but this makes Kenya about 10 metres long which is obviously not right and leads to an error ...
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23 views

How to make a simple square projection with specific coordinates in QGIS

I have been looking for ways to make our own projections but I always find complicated answers. I am a beginner and I am looking to make a simple square projection of 12288 by 12288 with x=0 and y=0 ...
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10 views

How to create updateable/inseartable view on QGIS with a sequence id?

I have a huge point dataset that takes a long time to insert new stuff when using QGIS This table has an id column of type serial To go around this problem I've created an empty view that has the ...
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20 views

Manage multiple users connecting on multiple Postgis database via QGIS

I have a question about QGIS projects and how to manage multiple users (fifteen users with usernames and passwords connecting to the same five databases in PostGIS). Right now, there is one project ...
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2answers
30 views

How to merge overlap polygon respectively in one shapefile in QGIS

I want to merge the polygons of one shapefile if they overlap, but I don't know what to do. I try'dissolve' but get only one final polygon. This is not what I need. I want to merge them respectively.
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1answer
28 views

Select features matching the values in an array (QGIS 3.10 expression)

I want to use an expression to select features matching the values of an array. Select features from a list is done by the IN operator: "field" IN ('value1','value2') But how to select features ...
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17 views

QGIS: interpolate difference in Z-value on enbankments

I have two layers: 1 polygon layer with a theoretical profile of a harbour. 1 pointlayer with output from my multibeam echousounder. I made a new pointlayer with a Z-difference between the two ...
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1answer
33 views

Points from QGIS to GEE

Let me preface by saying I'm a beginner but have read a lot and can't find what I need. I have a set of coordinates from QGIS that I want to upload to Google Earth Engine and I can get as far as ...
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1answer
34 views

Online Editing in QField (multi-user environment)

I have a QGIS Project that I run on QField to create points/lines and give them attributes in the Field. We have three tablets with the same project on it. Right now QField saves the new data "offline"...
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22 views

How to install scikit learn library for QGIS 3.4.7 on WIndows 10

I can not successfully install scikit learn library on my QGIS for windows. I tried the following on OSgeoshell: py3_env.bat python3 -m pip install scikit-learn --user And what I get is: C:\>SET ...
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28 views

Get Corresponding OSM Node IDS from list of Lat,Long (CSV): Map Matching

I have a list of (lat,lng) coordinates. I want to map match them and get their corresponding OSM node ids? How can i do that using OSRM or any other map matching algorithm?
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21 views

Reclassified slope raster attribute table in QGIS

I have reclassified a slope raster in Qgis 3.4, but how to open or generate attribute table of that reclassified slope raster? Slope ranges are on below picture. and my desired attribute table is as ...
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1answer
126 views

QGIS and 1-to-many relationship

I am using QGIS 3.10.0 I am attempting to join a spatial vector layer to a non-spatial layer (CSV). Each polygon on the spatial layer has a unique id attribute. The CSV also has this id attribute ...
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1answer
60 views

Using flat earth projection in QGIS

This is a flat earth model: flatearth Yes, it's funny, no, I'm not a flatearther. My interest is just exploring how the world would look like if the Earth would be flat according to this model. I ...
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28 views

{'code': 'NoMatch'} OSRM API: What does it mean? And how can I avoid it?

I have RAW GPS trackers data, when I match those GPS coordinates to nearest NodeID, it gives me the No Match Error. I am using the following code snippet: import requests url = 'http://router....
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39 views

UTM points from CSV end up in wrong location [closed]

I have a CSV file uploaded with UTM coordinates that should be located within Botswana. However they show up in the Indian Ocean and in Nothern Europe. We have tried standardizing the crs but it still ...
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44 views

'Layer is not valid' error in QGIS for delimited text layer

I am trying to add a CSV that contains lat/long coordinates as a layer to a project in QGIS but I keep getting a 'layer is not valid' error. Here is a picture of the data preview before I click Add: ...
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34 views

Merging and snapping shapefiles

I have several large shapefiles from various sources. All cover various sections of oceans and many overlaps, as such the coastline is repeated across the several shapefiles but to varying levels of ...
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0answers
32 views

Raster file not overlaying to vector layer

I'm pretty new to GIS and following a tutorial using shape files from Ithaca, NY. I've been able load a number of vector files easily enough but when I add in the .dem raster file it keeps being ...
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3answers
61 views

Concatenate string field in spatial join in QGIS

I'm doing a spatial join between a point layer and a polygon layer. The point layer has a field called "type" which has string values. When I join this to the polygon layer, I would like to get a ...
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0answers
19 views

QGIS Plugin Overlay Analysis Stuck [closed]

I am a bit new in p\Pthon programming in QGIS. Now, I am trying to develop a QGIS Plugin about Suitability Analysis using Ordered Weighted Averaging process. So in brief, I want to make a plugin to ...
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1answer
31 views

QGIS Select by Expression Parser Errors

My goal is to select all of the features in a layer with certain names. I have a list of 86 Subdivision names and a I am using a county Subdivision dataset, the names in the dataset include the ...
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2answers
33 views

With QGIS adjacent polygons, is it possible to “copy” one polygon edge to a new one? Like a “snap to” or “smooth to” the adjacent polygon?

I'm drawing adjacent polygons in QGIS. Whenever I create a new adjacent polygon, or if I've moved a polygon that has an adjacent polygon, I need to adjust the borders of the adjacent polygon to be ...
2
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1answer
25 views

Save Rule Based Symbology as Default Layer Style

I am constantly moving layers in and out of my projects, I was able to set default style for layers and they all the layers I drag and drop to my project get the same style by default. Lately I have ...
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20 views

Elevation profile for MultilineString (Shapefile) in QGIS

Is there a way to create elevation profile for multilines? I tried to use many methods like r.profile and plugins like Profile Tool, qProf and DataPlotly but it did not work as expected. These works ...
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2answers
40 views

Keep one distinct overlapping feature in a shapefile

In the attached image you can see that there are features in the shapefile that have the same geographical extent, I would like to find a way to only keep one of them and remove the rest. I would ...
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2answers
62 views

QGIS: Export 3D map in pdf not working

I am trying to export and save a 3D map as a pdf in QGIS 3.10 (using the composer). I am using the native 3D viewer and I am trying to understand how I can export and save it as a pdf. I set my 3D ...
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0answers
21 views

When creating a Nearest Neighbour from xyz, the raster cells are not centered with the original point cloud (QGIS)

I have a gridded point cloud 0,25x025. I ran a Nearest Neighbour with the same resultion (cell 0,25). The points of the cloud and the raster are not centered as seen in the picutre. Am I doing ...
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1answer
32 views

QWC2 first install

I'm trying to install QGIS Web Client 2 (QWC2) following instructions in "Quick start" documentation: https://github.com/qgis/qwc2-demo-app/blob/master/doc/QWC2_Documentation.md#quick-start So, I ...
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1answer
93 views

What does the 'EE' in 'Quantum GISEE' mean?

I'm doing some research on QGIS history and found in the German wikipedia article the term 'Quantum GISEE' (https://de.wikipedia.org/wiki/QGIS) but not in the English wikipedia article (https://en....
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0answers
31 views

How to reimport a QGIS 3.10 Vector-GeoPDF, generated from layout manager, so that all items not belonging to layers are hidden?

I'm very impressed with the new GeoPDF export capabilities of QGIS 3.10 (Windows 10). Now we can create Vector-GeoPDFs with layers included! With the help of GDALs "Geospatial PDF" file format ...
4
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2answers
73 views

Exporting multiple point shapefiles from one file using QGIS

I have a point shapfile of species records (about 100 species), with many georefenced ecords for each species. I'd like to export one point shapfile for each species. I can do it by selecting by ...
2
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1answer
46 views

How to create a GRID with customized Labels in QGIS

I would like to know how can I create a GRID layer with customized labels as you can see in the image below: I have searched this topic here: Creating indexed vector grid in QGIS? QGIS Python ...
4
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1answer
38 views

Getting 2 point features with max/min ID from each group with same value in two fields

I'm working in QGIS for a Digital Terrain Model. I've got a table with point features, arguably vertices extracted from multipart iso-curves because the features are provided with a "vertex_par" ...
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1answer
23 views

Data Extraction [closed]

I am a very new QGIS user. I have a Digital surface model prepared and now I want to divide that whole area into multiple grids and need to extract the values( lat, long, elevation) of each pixel.And ...
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0answers
19 views

Dzetsala plugin on QGIS, missing scikit-learn

I want to run random forest classification from Dzetsaka plugin on QGIS 3.4.7 but I can't as a message appears as following: Scikit-learn library is missing on your computer. You must use Gaussian ...
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3answers
33 views

Convert coordinate to DMS in QGIS

I'm trying to convert coordinates to DMS, I try to use field calculator, but I still have no result. I also try this script: (CASE WHEN $x < 0 THEN '-' ELSE '' END) || floor (abs($x)) || '°' ...
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0answers
24 views

Checking raster value type in QGIS

I naively assumed that the rasterType() function would give me the data value type for the raster (i.e. integer or float), but it just tells you whether it's a singleband or multiband raster. Is ...
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0answers
19 views

How can I remove missing values on QGIS?

I have a data set that uses the number -9999.000 to represent missing values. I need to remove these missing values in order to make some calculations, but I am unsure how to go about this.