Questions tagged [qgis]

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

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19 views

Web form builder for feature editing

Is there software for graphical web form building with similar features that are available in QGIS feature form builder? I love how easy it is to create forms in QGIS. I have lots of data that ...
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3answers
39 views

Why does QGIS shift the raster during raster calculator operation

I have a raster with bathymetry data and need to add 0.6 value to each cell. The operation itself is simple - I just use raster calculator to add the value using following expression: bathymetry@1+0.6....
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1answer
51 views

Calculate distances between consecutive points in QGIS

I have a large dataset containing GPS points of various vehicles that are recorded every 10 seconds. I have added a new id column to these GPS points in order to be able to connect them via the ...
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1answer
21 views

Formatting numeric fields in attribute table in QGIS

In ArcGIS you have the following window that allows you to visualize your numeric values in your attribute table in a diffrent manner. (Sorry the Image is in German) In the example numeric values ...
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1answer
81 views

QGIS Labeling break underlined

I want to create a labeling for a polygon layer. The labeling should constists two columns from my file, "X" on top, "Y" among "X"and they should be separated through a break underline. Every column ...
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37 views

Exporting font (labels) on qgis2web

I am using QGIS and qgis2web to make a simple historical map. I have many problems because I am an amateur, but I am solving them through a search. But as you can see in the picture, I have a problem ...
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1answer
20 views

Hyperlink from attribute table gets send to browser missing the last character, }

I am using QGIS 3.10.2-A. I'm working with city data and parcels. I populated my attribute table with a lengthy hyperlink that ends in }. The string is about 455 characters, and it shows in the ...
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1answer
46 views

Creating Latitude & Longitude from polygon shapefile using QGIS

Could you help me to create long & lat (x and y coordinates in degrees) for polygon shapefile? When I used directly QGIS export vectors to csv file, it didn't work. Here is the example file: ...
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53 views

Define custom projection in QGIS from some control points

I have six control points in a local mine grid which I want to use to define a custom projection in QGIS. The reference points are in GDA94 / MGA zone 50 (EPSG:28350) (https://spatialreference.org/ref/...
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2answers
33 views

Trying to merge 800+ shapefiles getting “Incorrect parameter value for LAYERS”

I have 800+ shapefiles and some of them have different type of attributes. When I use Merge Vector Layers and select all my shapefiles I get "Incorrect parameter value for LAYERS" error. When I ...
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2answers
84 views

QGIS 3.10 install on Ubuntu 18.04 will not recognize any projections

As the the title states a clean install of QGIS 3.10 on ubuntu simply will not recognize any projections and sets all data (both raster and vector) to unknown projections. This issue even extends to ...
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2answers
80 views

Installing latest version of QGIS on Ubuntu 18.04

I'n not an experienced user of Linux. But I just wanted to install the latest version of GRASS GIS and QGIS on Ubuntu 18.04. There are many different ways to do this I guess. There are the ppa's, ...
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33 views

Column names have moved in attribute table QGIS

I've joined an excel spreadsheet to one of my point shapefile. After performing the join, I can see that the names of the columns have not been set as the name in the attribute table column; instead ...
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0answers
24 views

Problem when using Simplify Tool in QGIS

I want to simplify district borders. As I got bad results when using polygons I converted those polygons into lines but I still have the same problem that I get new vertexes or corners I don't want. ...
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1answer
36 views

Importing Shapefile to PostGIS using QGIS DB Manager

I am trying to import a shapefile from my QGIS project to my PostGIS schema using DB manager. I want to create a new table in my public schema and I have an ERROR: relation "spatial_ref_sys" does ...
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1answer
26 views

Output of an algorithm in QGIS Graphic Modeler

I use two Processing tools in a graphic Model in QGIS: 1-Select by Location 2-Select by Attribute The problem is that I can't get the output of the selection by location so that I can't use it as ...
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2answers
143 views

Counting unique features of points inside polygon in QGIS

I have a series of points with various fields in the attribute table, including a car_id. I also have several polygons in which some of these points are located. I want to count how many unique ...
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1answer
54 views

Connecting number parameter to Field Calculator in QGIS Modeler

I intend to develop a model with field calculator processing using the QGIS Modeler. How do I include the number input by the user to be as a value in Formula of Field Calculator? This is the model ...
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26 views

WFS request using layer extent or spatial query QGIS3

I'm trying to request features from wfs-service by using a virtual layer. Is it possible to load features by using a layer extent from a virtual layer? I know how to add dimension for a request with ...
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1answer
30 views

Exporting layer to shapefile after styling using Python in QGIS

I'm trying to use Python to add a GML to my QGIS 3.4 project, apply styling to it, and then export the layer as a shapefile. It exports the layer, but it does so before applying the styling, which ...
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2answers
37 views

How can I Export transparency and text well when using qgis2web in QGIS 3.8?

Hi, I am an amateur who is making a historical map. As you can see in the picture, I have a problem using qgis2web. The first picture is a normal scene output from QGIS version 3.8. The second ...
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1answer
27 views

Show or hide bands in GeoTIFF rasters (using QGIS)

I have a bunch of GeoTIFF images that show aerial photos of various fields. Bands 1-3 in these images contain the R/G/B components of the original photo. Bands 4-6 contain additional information about ...
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51 views

Export a very large attribute table (1,5 M rows) into Excel spreadsheet QGIS

I have a very large shapefile containing rainfall data for South Africa. Each point is a single rainfall that lasted for 1 hour. I have 1,5 million points. For further analysis, I need to export it ...
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2answers
74 views

Plotting point every x m2 in polygon using QGIS plugin

I'm trying to work out whether its possible to plot a point every so often within a polygon. For example, if I have a polygon thats 200x200m, perhaps I could plot a point at every meter squared ...
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1answer
130 views

Making map with gradation polygon using QGIS

I am making a history map on my website these days. (http://eastmaps.com/2019/09/10/%ed%85%8c%ec%8a%a4%ed%8a%b8/ < it's my test version) But like this site(https://www.ancient.eu/map/), I want to ...
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1answer
38 views

Extract cross-sections from a DEM

I have the centerline of a river and multiple lines perpendicular to it on Qgis. I would like to extract the cross-sections in correspondence to those lines, how could I do? I tried qprof but the .csv ...
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1answer
56 views

QGIS 3.10.2 - Install PostgreSQL and PostGIS

QGIS 3.10.2 in Ubuntu 18.04. I'm having problems installing PostgreSQL and PostGIS following the instructions here: Installing PostGIS under Ubuntu. This doesn't work, 'postgresql-9.1-postgis' isn't ...
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2answers
130 views

Definitive list of QGIS multiprocessing tools?

This question is not as straightforward as it seems, but can be summed up with the following: Is there a definitive list of geoprocessing tools for QGIS that currently support multithreaded ...
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27 views

How to work in the form of QGIS PostgreSQL fields which is of type array[]

I have a table in a PostgreSQL / PostGIS database where there are columns of type array [] and I would like to know how to work on the QGIS form. Example: I have a column called "WALLS" and that ...
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1answer
82 views

Organize all dialogs in one package QGIS 3 Plugin

To organize better the code in my QGIS 3 Plugin, I tried to put all dialogs in one package called dialogs, but when I open QGIS it says ModuleNotFoundError: No module named 'dialogs' This is the code ...
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2answers
101 views

Removing overlapping polygons in QGIS

How do I remove overlapping polygons in QGIS 3? I've tried v.clean (bpol, rmdupl and rmarea using right tolerances) and when I check the topology after doing that it says there is no overlapping but ...
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39 views

Installing QGIS on Debian only gets the LTR

I am trying to install QGIS 3.10.2 on Debian Testing. I read the install instructions and have updated my apt sources.list file to: deb https://qgis.org/debian buster main deb-src https://qgis.org/...
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1answer
54 views

QGIS Live GPS - turn the map according to the direction I move

Using Live GPS in QGIS I would like the map to be rotated automatically, that the direction I am moving to is always upside like in a car navigation sytem. How can I configurate that?
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49 views

Function to make a trajectory more straight

I'm new at PostGIS and I have to do a project for my university course. I'm trying to analyze a trajectory of points that I downloaded from my runtastic app but it's a mess. There are some points ...
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2answers
42 views

Saving Virtual Raster Layer with Project using QGIS

I have a project that uses multiple DEM tiles to create a Virtual Raster Layer. The Virtual Raster is then used to calculate a Slope and an Aspect layer. I've attempted to save the Project, but when ...
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0answers
40 views

Did the syntax for proj4 change with QGIS 3.10?

In QGIS 2.8 I was able to successfully do a transformation using the following proj4 syntax : +proj=utm +zone=18 +ellps=clrk66 +datum=WGS84 +towgs84=-11.0584,163.8703,190.541,0,0,0,0 +units=m +...
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0answers
14 views

Processing Modeler QGIS Issues With Interpolation Step

I am trying to interpolate Sampled Points with IDW Interpolation in the QGIS processing modeler. For some reason I am not able to select the Sampled Points with the IDW Interpolation. Anyone know ...
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0answers
40 views

Why is my PYTHONPATH setting itself to QGIS?

I'm trying to cleanup Python on my Mac. I keep getting this message in Terminal: Your PYTHONPATH points to a site-packages dir for Python 3.x but you are running Python 2.x! PYTHONPATH is ...
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23 views

QGIS Least cost additional constraints

I am looking to create a least cost path for a pipe line based on a landslide risk map. I was wondering if a least cost analysis has the possibility to put additional constraints on the pathing i.e 90°...
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1answer
36 views

Delete overlapping points between two shapefiles QGIS

I have a point shapefile of all human settlements in South Africa (ranging from tiny hamlets to major cities). In another shapefile, I have point features as well, representing settlements located ...
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1answer
41 views

Producing plant height with digitial surface model

I am trying to produce plant height with a digital surface model "TIF" file that was obtained with a drone. I have clipped out the section with plants and then used "Gap Fill" to produce a digital ...
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0answers
30 views

Font opacity in QGIS [closed]

I am setting this font to be only 30% opaque but the display and printing of the font is not changing. What am I missing?
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1answer
18 views

gdalwmscache folder on Windows

Could somebody explain what the gdalwmscache folder does? Is it save to delete the gdalwmscache folder on Windows? Is my file still able to be opened? I can't test this so it would be nice of someone ...
2
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1answer
41 views

Place a special function or action with QGIS

I use QGIS and want to place an option that when pressed, I perform a filtering without the need to enter commands. I am currently using the program to carry out an electricity project, where a ...
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0answers
30 views

Gdal format command not found

I am trying to clip a raster image based on a vector mask layer and I am encountering this error: Gdal format command not found. I am on a Macintosh and my QGIS version is 3.4.
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1answer
24 views

QGIS Raster Mask Layer?

I have a raster slope layer and a raster aspect layer. The slope layer is single band grey, that is black to white, with white as the steepest slope. The aspect layer is pseudo colour. I'd like to ...
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1answer
36 views

Batch field-calculator with a decimal result

Is it possible to carry out a batch field calculator process in QGIS across multiple layers resulting in a decimal number? I have manage to do it and get an integer but not a decimal. There are only ...
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0answers
70 views

Functioning QGIS Server for Windows 10

I am trying to set-up a QGIS Server on 64 bit Windows 10 to be used with Lizmap. I am following these steps: https://opengislab.com/blog/2018/7/7/updated-installing-apache-qgis-server-and-lizmap-on-...
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17 views

This post is hidden [migrated]

How do I make the answers to my questions posted earlier visible? https://gis.stackexchange.com/questions/294451/using-rasterfromxyz-in-r-for-qgis-under-krige-baye?noredirect=1#comment472727_294451
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1answer
36 views

Why are certain GCPs in my georeferenced scanned map resulting in warping? (QGIS)

I am having issue with georeferencing a scanned map. Warping has occurred in the West in Morocco (near Marrakesh) as well as a sort of "black holes" in Libya and Northern Chad. As far as I can tell, ...

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