Questions tagged [qgis]
QGIS is a cross-platform GIS application licensed under the GNU General Public License.
29,258
questions
-8
votes
0answers
36 views
Forum moderation [closed]
New on this forum and suprised to see that some users spend there time to add or remove spaces in the message posted by other users.
A job that is similar to the GAFAMs content moderators, unhappy ...
2
votes
1answer
33 views
Getting unique values in a QGIS Expression
I'm using QGIS 3.4 attribute form to edit the widget type.
I'm trying to retrieve "cab_no." field values (only unique values) from 'U_Cabinet' layer to use it in "fdt#" field in ...
1
vote
1answer
18 views
Making colours from table with colour percentages/RGB-codes
Currently, we have a big dataset imported in our QGIS profile. Normally we would have imported this by WMS but because this particular WMS/WFS consists of more than 20 parts and the data is ...
0
votes
0answers
18 views
QGIS how to batch process zonal statistics?
I'm trying to figure out how to run "zonal statistics" in QGIS 3.8.2 (qgis:zonalstatistics) on multiple hundred shapefiless with building footprints and corresponding raster files (each ...
0
votes
0answers
22 views
How to convert rainfall time series to raster?
I have a rainfall time series for 10 hours in increments of 0.250s, I need to convert it from a .txt-file to a raster.
I've tried using r.mapcalc in GRASS, however, have not been successful. I've also ...
1
vote
1answer
16 views
Linear referencing using virtual layers in QGIS
I am trying to replicate the behaviour explained on this page.
There are two initial layers :
One network layer (line geometry), called base_lines (fields : LB_idRiver)
One event layer (non-...
0
votes
0answers
30 views
Buffer around suburb lines
I am using QGIS 3.6.3 and I am an amateur QGIS user.
My QGIS project currently has a map outlining suburb boundaries in New South Wales, Australia. I am wondering if I can create a buffer around ...
0
votes
0answers
35 views
Apply a date filter to the vector layer
I am new to developement in QGIS. I use a the 3.4.4 version of QGIS.
My vector layer is like this:
So I want to know how to filter this data by date and apply the changes in the GUI. Here is what I ...
1
vote
2answers
28 views
QField use main-detail tables from PostGIS/PostgreSQL
We are using QField for field data collection (forest survey). Our data is stored in a PostGIS/PostgreSQL database and we use QFieldSync to export and import data. This works fine as long, as we use ...
0
votes
1answer
39 views
How to fix the label position after using automated placement in QGIS
I'm making a city map using QGIS 3.14 and I want to label every street (that's around 5000 label, the map is an A0 size at 1/12 000 scale). There are no other label than the street name and all label ...
1
vote
1answer
36 views
Shapefile not displaying correctly
I'm very new to QGIS, but have used Arc a bit. I've downloaded a shapefile of the Home Owners' Loan Corporation "residential security maps" from the 20th century (i.e. redlining maps). I ...
0
votes
0answers
18 views
Standalone scripting and temporal controller
I have a couple of slightly related questions arising from my efforts at producing a collection of PDF maps from a collection of temporal GIS data. One key thing I am dealing with is that I my data ...
2
votes
1answer
18 views
QGIS buffer of lines results in “random” vertex order in buffer polygon
I tried this topic already on QGIS dev mailing list:
I have a fairly complex geometry-(and mind-)bending workflow where I'd ideally depend on the fact that buffering a line (regular buffer, flat cap, ...
2
votes
1answer
40 views
Managing large numbers of raster DEMs for QGIS
I have a large number of (say 9000) 2km x 2km raster DEMs in ASC file format that I am trying to manage, in order to use in QGIS.
I've been looking for way of storing them, ideally on the filesystem, ...
0
votes
0answers
11 views
Manually scale polygon feature in QGIS
I want to manually scale selected polygon feature in QGIS so I don't need to set any parameters, just click on the feature and scale it moving the mouse. In ArcGIS there is a Scale tool. I want the ...
2
votes
1answer
36 views
Bulk adding custom CRS in QGIS
I have a list of more than one hundred CRS defenitions in PROJ4 format in a plain text file (csv, tsv or txt). I'd like to know if there is any way of adding them into QGIS database at once. The "...
0
votes
0answers
21 views
Imported DXF has no position attribute using QGIS
I am using QGIS 3.10.8 and still getting my head around QGIS.
I'm trying to import some route data from dxf into my QGIS project. when I import and set the CRS correctly it is in the correct place, ...
1
vote
0answers
12 views
Combining different svg fill symbols in QGIS without overlapping
Is it possible to get a polygon filled with a couple of different SVG fills without overlapping?
I want them to go side by side forming a mosaic, instead of overlapping each other, but can't find how (...
1
vote
0answers
8 views
Restrict Layer Style getting saved in QGIS project table in PostgreSQL
As postgres admin , I have created a layer and styled the same in QGIS AND saved the style in postgres. When another user uses the same project(user have been given the grant to access the project) ...
-1
votes
0answers
34 views
QGIS: Buffer area issue [duplicate]
I'm new in QGIS and I try to properly generate a buffer layer.
My config is:
-Debian buster (10)
-QGIS v2.18
-The numeric separator on my machine is coma not dot.
I created a project with the ...
0
votes
1answer
19 views
Entering UTM Map Coordinates when georeferencing is not working
I'm trying to enter UTM map coordinates from a scanned image (grid), and I'm entering the coordinates correctly X/Y, but when I click to process the georeferencing - the image does not overlay where ...
-2
votes
0answers
20 views
QFieldSync plugin reports “No space left on device” during packaging
I am trying to configure a QGIS project using QFieldSync plugin but it keeps giving me Python error when I try to package the project for QField
Traceback (most recent call last):
File &...
0
votes
0answers
17 views
How to “merge” multiple raster ASTER L1T bands?
I want to generate a Land Surface Temperature map using ASTER products. I used the Semi-Automatic Classification plugin and followed this tutorial. However my study area is too large and required at ...
1
vote
0answers
26 views
QGIS: Dissolving stacked polygons into non-overlapping “donut” features
I am trying to get my head around what I think is a fairly straight forward geoprocessing problem:
I have created a polygon contour layer. However the polygon features are stacked on top of each other ...
0
votes
1answer
22 views
Missing / misnamed fields in PostgreSQL table join in QGIS
First, I'm brand new to PostgreSQL and PostGIS, so my question is probably asked wrong, and it may be a duplicate – but my search attempts didn't find anything. Also, I don't expect this is an issue ...
0
votes
0answers
16 views
Local Package Directory QGIS 3.10.1 through to .8 [closed]
I have been asking QGIS support finally giving up with them to inform me how to change the default Local Package Path in Windows .
I reported to QGIS that their current use of Windows /Users /local /...
2
votes
0answers
26 views
How to select one field and delete all others QGIS graphical modeler
In the Graphical Modeler in QGIS I have the algorithm to Drop Fields, which you select the fields you want to drop:
However, the vector layer I'm using has many fields but I just need one in the end.
...
0
votes
0answers
15 views
QGIS Action Open Image
Can someone advise me where i might be going wrong when trying to open an Image in a Network folder using the Action function in QGIS
I have a point dataset with a column that has the image location ...
2
votes
1answer
28 views
Using Split vector Layer in QGIS
I am trying to split a vector file using an attribute value and wants to name the each created output as the name in the attribute field. I am being able to split the vector layer but it is giving ...
1
vote
1answer
34 views
Imported polygon from Google Earth is not being merged
I'm new to QGIS. I need to merge two polygon that I have imported from Google Earth (.kml) but when I try to do so I am getting an error message
Not enough features selected: The merge tool requires ...
1
vote
1answer
53 views
Coordinate Transformation Difference between QGIS and Proj
I transformed coordinates on PyQgis and Proj command line and there is 3.8 meters difference between the transformations. I used the same EPSG codes.
For Proj 6.3:
echo 35.53 38.75 | cs2cs +init=epsg:...
0
votes
0answers
20 views
Raster Resampling / Clipping? QGIS
When I am trying to resample a raster layer or to clip it by mask layer the pixel value get automatically changed in the output file irrespective of every setting. Why it is happening and how can i ...
0
votes
1answer
50 views
Change center of projection (QGIS) [closed]
I'm working with this
mosaic from Pluto.
It is projected in simple cylindrical.
I need help to change, using PyQGIS, the center of the projection to the coordinates of a specific point, or to a ...
0
votes
0answers
8 views
UMEP Copernicus downloader ERA5 throwing Python Error
I am very new to using UMEP and I have installed it on QGIS 3.10 on MacOS and also on Windows but in both machines, I am running into the following error. I have set up my id/key API properly as I can ...
0
votes
0answers
23 views
How to run an exported QGIS program as a stand-alone application?
I have a research partner who exported their QGIS algorithm to a python script, and my job is to use that Python file to create a web application that provides access to that algorithm.
My eventual ...
-1
votes
0answers
24 views
Converting 2D into 3D in QGIS [closed]
I want to ask if somebody can tell me the options how to convert 2D into 3D in QGIS...
For example I already know that there is the option of extrusion... Are there any other options?
2
votes
2answers
35 views
QGIS expression to check if a an attribute value of a feature exist in another attribute column
I have a shapefile with two fields 'Name' and 'CountyFacilityID'. I would like to create an expression to select all features where Name exists in the CountyFacilityID column for any of the features.
...
0
votes
0answers
15 views
QGIS: Merging many vector layers of the same name together
This topic has some relation to my other topic here:
Extracting catalog consiting of name of layerdata/tabel of bunch of different geopackages
Because it is kind of a sequel to this one and you guys ...
1
vote
1answer
25 views
QGIS: Change attribute values from NULL to 0 for all attributes using Python [closed]
I have an attribute table where I have occurrences of NULL spread throughout in different attributes and features. How can I change NULL to 0 using Python for all attributes?
0
votes
1answer
23 views
Convert a WFS GET request to a WFS POST request [duplicate]
I have a WFS GET Request, created by A WFS Layer in QGIS. However, for my program I need to have a POST Request. How do I convert the WFS GET request to a WFS POST request?
2
votes
1answer
31 views
QGIS 3.10 (and newer). Random points inside polygon (Variable) tool is missing?
Using the current long term release version of QGIS (v3.10), I see the 'Random Points Inside Polygons (variable)' tool is changed. It used to look like this.
The key field here is the 'number field'. ...
1
vote
1answer
47 views
How to merge several shapefiles with the same geometries and same attribute names?
I have data from several runs of a numerical modeling tool. The data always has the same structure - e.g. fixed set of rectangular vector tiles - no matter if there is a "valid" output or ...
4
votes
2answers
57 views
How to insert missing vertex of two geometry overlaps area in QGIS
I need to add the missing vertex of two lines intersection places using QGIS.If any default plugins or tools available for fixing missing vertex in qgis,kindly suggest me.
My Inputs:
In above ...
-1
votes
0answers
17 views
Need to change center of the map [duplicate]
I have a world based map and I extract asia pacific region, now I need to make this region to be in center of the map. I using qgis. How can I make it?
-1
votes
0answers
24 views
How can I create a slider map from SQL or Excel that updates every day? [closed]
I've been able to make a slider heat map that lets you slide between days. Every day I want to add a new layer (3000 values) so that tomorrow there will be 18 days/heat maps on the slider, and so on. ...
3
votes
1answer
89 views
QGIS not recognising field names in first row
For some reason, when I add a CSV as a delimited text layer QGIS is not recognizing field names in the first row. This has only been happening the last week or so. I am pulling my hair out.
Below is a ...
0
votes
0answers
44 views
Importing .bag (bathymetry) files into QGIS 3.x
I downloaded bathymetric data from the NOAA Bathymetric Data Viewer website: https://maps.ngdc.noaa.gov/viewers/bathymetry/
I've tried to import and view several .bag files from this website within ...
1
vote
1answer
31 views
Missing mapsettings.ui while loading QGIS Cloud 3.1.8
I have an issue with QGIS Cloud 3.1.8. The plugin installs nicely but doesn't load due to the following error message.
FileNotFoundError: [Errno 2] No such file or directory:
'C:/Users/ahmed/AppData/...
0
votes
0answers
21 views
QgsVertexMarker pyQGIS hangs QGIS 3.14 UI
I am using QgsVertexMarker API to mark the current position of the polyline that is being used to display a track. I use the setCenter API to move my marker to the current position using python. ...
1
vote
0answers
29 views
Show GIS data on website using automated qgis2web process [closed]
I managed to export my GIS map to my website through Qgis2Web. My map shows a daily view on a specific infestation of parasites in the poultry industry and I want this updated once a day, say at ...
