Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [qgis]

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

1
vote
0answers
16 views

What does cumulative count cut actually do?

I have a grayscale satellite image (16-bit image) which is dull (low brightness). When I apply cumulative count cut from 2 to 98 percent (Properties -> Min-Max Setting -> Cumulative count cut), it ...
1
vote
1answer
20 views

Selecting polygons over raster extent using QGIS?

I would like to select all the polygons that are within my raster extent. Is there a tool in QGIS to do it ? Such as the select by location tool but instead of comparing the features from another ...
1
vote
1answer
22 views

Is there an alternative function which does the same thing as clip raster by masked layer on QGIS?

I am having some technical problems with the clip raster by masked layer and I faintly remember using a different method a long time ago for a similar problem. Anybody familiar with another function?
1
vote
1answer
33 views

Opening .clim file with QGIS

I downloaded data from http://climate.geog.udel.edu/~climate/html_pages/download.html in order to retrieve temperature and precipitation data. What I actually want is mean temperature and ...
-2
votes
0answers
33 views

Processing “buffer” Rectangle Polygon containing X points of another layer and next one overlapping based using QGIS?

Let me be clear, I know how to create a buffer based on distance but not based on other criteria. I have collection of a lot GPS points in a Shapefile, which are actually documented trees per GPS on ...
2
votes
2answers
44 views

Delete several tables in QGIS DB manager

I have a lot of tables in a PostGIS-Database and I want to delete most of them. In the QGIS DB manager, I am able to delete one by one (right-click - delete). However, that's quite annoying. How to ...
0
votes
0answers
30 views

GDAL OGR Polygon.Contains(Point) returns false but point is contained in QGIS map

I'm sure I must be missing something here but for the life of me I can't see what it might be. I have been struggling for the last hour with an issue with the Contains() method in OGR. I am iterating ...
-1
votes
1answer
38 views

Adding service to QGIS

I've tried to add this link as a service and it hasn't been working. I'm starting to wonder if it is even possible. https://kyraster.ky.gov/arcgis/rest/services/ElevationServices/...
0
votes
0answers
40 views

Error message: Commit errors when creating a new shapefile

I want to create a shapefile (ESRI shapefile) layer in QGIS version for 3.6.2 for polygons however I keep getting error messages at first it was: Error: could not commit changes to layer error 1 ...
1
vote
1answer
42 views

Editing shapefile from QGIS in ArcMap causes errors according to QGIS topology check?

I noticed Polygon shapefiles that were edited with ArcMap yield many errors in the QGIS Topology checker. The picture below shows a polygon Shapefile. I made one error on purpose so the topology ...
1
vote
1answer
42 views

Union, merge, intersection, join layers - logical difference and clear explanation for QGIS

I note that there are answers available on the difference between join and merge (e.g., Difference between 'join' and 'merge'?) that link to ArcGIS resources as a reference. However, I ...
0
votes
0answers
40 views

Merging Degree Two nodes in Stream Network using QGIS 3.4

I have a stream network and I want to convert it in graph like data structure, for which I need to have precise set of FROM and TO vertices.The geometry of stream network is not correct i.e. the ...
0
votes
1answer
38 views

Classifying coordinates on land/on water using QGIS?

I am a new user of QGIS. I'm looking for a solution for my problem. I have my own dataset providing the latitude and longitude of different unique ID's. Now, I would like to classify those ID's that ...
2
votes
1answer
42 views

Converting 0 to NULL in attribute table

I am using QGIS 3.4 and I want to change all my 0 values to NULL. How can I do that in the attribute table?
2
votes
1answer
67 views

Difference between JOIN ON and WHERE in Virtual Layers in QGIS

There is already a question on this topic Difference between SpatialJoin with “…where…” and “join…on…”. However, it is dedicated to PostGIS. Since in the Virtual Layer query window, I cannot simply ...
1
vote
1answer
27 views

Listing active radio buttons within tab widget or layout?

I have a plugin widget with some tabs, and within the tabs a layout of radio buttons as shown below: I would like to capture the list of active radio buttons within each tab like so: Is there an ...
0
votes
1answer
26 views

How to make query of MySQL connection in QGIS?

i have added a connection with a MySQL database in QGIS (Add vector layer - Database - MySQL). Is there an option to make a query over the database in QGIS?
2
votes
1answer
46 views

Extract midpoint coordinates from TIFFs (QGIS)

I have a large collection (>20000) of georeferenced satellite imagery tiles in TIFF format. Each of them has a size of 64x64 pixels. Is there a way to extract the lat/lon coordinates of the midpoint ...
1
vote
0answers
21 views

Transforming TM75(29903) squares to ETRS89(3035)?

A bit of a long winded explanation here so please bear with me. I have received grid square data in ETRS89(3035) which I need to cross reference with out own grid squares which are in TM75(29903). ...
2
votes
1answer
87 views

Compress Large size of satellite image by Open Source GIS software [closed]

I have a new challenge to compress large size of satellite image from 59GB to 10GB as maximum size by Open Source GIS software to publish it to GeoServer.
2
votes
1answer
64 views

QGIS very slow and stops when increasing points size / number

I used the "graduated" style option to represent data by year. Then for each year I used this method with a custom function to increase point size according to the number of points at the same ...
0
votes
1answer
35 views

Error: Geometry constraint geom-type or SRID not allowed. How to ensure the correct geom-type?

Following the top answer on a previous question about storing geometries in a spatialite database, I am trying to update a spatialite table using: engine.execute("SELECT AddGeometryColumn('your_table'...
1
vote
1answer
35 views

Identifying connections/ intersections of vectors

I would like to identify which vectors connect/ intercept within the same layer. In more detail I have 1000s of vector lines and I would like to identify which lines are connected to each other ...
4
votes
1answer
48 views

Adding up several rasters to show the change

I want to add several images such that their change is shown in different colors. Such as the following in which I simply added two images in their grayscale. But I would like to have a colored ...
1
vote
0answers
29 views

Using Pyqgis 3 to select features from attribute table by expressions

I have a shp with the following attribute table: The column Line_ID represents each line (line 0, line 1, line 2 ... ). The column ID are the points id (point 1, point 2 … ). The column Declividad ...
0
votes
0answers
20 views

Node incorrect arrow styling [duplicate]

Is there any way to create arrow styling (but with one head only) so that it is consistent with vertex? I have tried all combinations of 'curved arrows' and 'repeat arrow on each segment' but they ...
1
vote
0answers
37 views

How to import orthomosiac from metashape into QGIS and preserve ortho apperance?

The beautiful image that you see is an orthomosaic [apparently this is not a yet a tag on this forum] generated in Agisoft Metashape [also not a yet a tag] with imagery captured with drone mounted ...
3
votes
1answer
62 views

Looping through file names in QGIS?

I am working with a Mac OSX El Capitan, QGIS 3.4.5 Madeira and Python 3.6.1. I have a question which I believe is essentially a python one but applied into QGIS. I intend to program some algorithms ...
2
votes
2answers
111 views

Comparing and find out which feature has highest shape area in QGIS?

I need to find out which polygon is having more area by filtering unique ID. the problem is I have 1000 of features which I need to find out highest occupied area for every unique value... since I ...
2
votes
0answers
38 views

Attribute from point to line using end Vertex of a line - py console

I have a line feature and a point feature. I would like to join the attribute of a point feature to the line feature based on end vertex, so when end vertex of a line falls on a point, the line ...
2
votes
1answer
66 views

Interface of QGIS plugin created by QtCreator

The image below is the interface of the plugin which I created using Qt Creator. However, when I loaded this plugin in QGIS3 (version: 3.6.1). The interface of the plugin does not appear completely. (...
2
votes
0answers
38 views

Creating subplots 10m^2 using QGIS? [closed]

I would like to create a few subplots within my project, I don't really know how to do this in one layer I've tried creating polygons but that isn't really what I want I just want the boundary to ...
4
votes
1answer
72 views

QGIS Draw by rule

I have a point layer with several colored dots. Each dot represent a find of a bumblebee species. E.g. red is B.terrestris yellow is B.hypnorum. In my attribute table I have a column named "nest" (...
-1
votes
1answer
29 views

Using raster for r.sim.sediment?

I'm quite new to QGIS. What data will I need to use the r.sim.sediment processing tool?
1
vote
1answer
47 views

How to use a regression equation to create a map in QGIS?

I have been working on creating an exposure map based on measures taken at fixed points. I want to extrapolate the results to a grid to get an exposure map (air pollution data) for a region based on ...
5
votes
4answers
123 views

Finding distance between buildings and nearest road using QGIS?

I am very new to working with GIS data. I am currently using the QGIS tool to work with the data. I have two datasets: Buildings - polygon shapefile with information about different buildings in a ...
2
votes
0answers
40 views

PyQGIS: creating a feature from multiple linestrings

I am trying to create a closed linestring made of a number of circularstrings, but have got stuck. I cannot see how to add the geometry from both strings. This is what I have so far. QGIS version 3....
3
votes
1answer
140 views

Loading shapefile in GeoDjango and displaying it in admin section?

I am trying to load a .shp file in GeoDjango Admin. As a newbie I followed their official documentation and based on that I am trying to load my own shapefile. No errors are being shown but I can't ...
2
votes
0answers
38 views

Finding Intersection Points in Stream Network using QGIS?

I have a stream network and I want to find the red points as shown below. I have tried using Q-chainage and Line Intersection feature in QGIS but it gives more than expected number of points. The red ...
1
vote
1answer
39 views

Cropping GeoTIFF to square at specific lat/long for use as Unity 3d terrain heightmap?

I have some GeoTIFF files that contain elevation data. I have an area defined by latitude and longitude, and I would like to extract the elevation as a heightmap from the GeoTIFF files to use in Unity....
0
votes
0answers
35 views

Adding navigation to QGIS Shapefile?

I'm looking to create an APP with Navigation Offline. The problem is my point of interest is not offered by OpenStreetMap (OSM). I would like to know if can i add navigation to a shapefile (mine) or ...
0
votes
0answers
41 views

qgis2web incorrect leaflet popup position

I have encountered some problems with positions of popup containing image in leaflet format (version) of this great tool. Sometimes has the pointer of popup (in a picture marked with red circle) ...
3
votes
1answer
50 views

Is there a way of creating a flowchart in QGIS or an alternative?

Currently I have thousands of animal trails and I want to analyse the network to see which waterholes trails lead to or if they are fragmented by roads. I tried exporting the CSV file to gephi another ...
0
votes
0answers
51 views

QGIS Hillshade Too Dark

When producing a hill-shade from Raster_>Analysis->Hill-shade in QGIS, I cannot stop my hill-shade from becoming too dark, leaving massive parts cities to be black. I have tried the extremes and in ...
1
vote
0answers
26 views

How to calculate walking distance between multiple addresses? - QGIS

I am working with historical data and I would like to calculate the walking distance between multiple addresses. For instance, in my excel dataset I have someone who lived on 1 Laurierstraat in ...
1
vote
1answer
29 views

QGIS 3.4 changing feature attributes

I am using QGIS 3.4 and I have unintentionally labelled two lakes with the same name as they are listed as one feature in the attribute table. I cannot figure out how to change the feature attribute ...
1
vote
0answers
32 views

Using QGIS Map Swipe Tool?

I'm using the Map Swipe Tool in QGIS 3.6.2 on a Mac and a PC. I'm using the tool on two imported raster layers to compare changes in temperature. On the PC, it works just fine. On the Mac, I'm getting ...
0
votes
1answer
31 views

Getting MapBox basemaps into QGIS?

Have been playing around with this answer for a while and I can't get it to work in QGIS 3.4.4: https://docs.mapbox.com/help/tutorials/mapbox-arcgis-qgis/#add-mapbox-maps-in-arcmap No help on ...
2
votes
1answer
43 views

Moving a set of rasters in QGIS

After running a GRASS watershed algorithm I've got nine new layers: Each one is in its own folder with a long hex name under a processing folder with a long hex name: /tmp/...
7
votes
1answer
100 views

Connecting offset point symbol to its original position in QGIS?

I'm drawing a track where I want to place icons (point symbols), but with an offset so that the line is fully visible. Here is an example: The origin is exactly on the track, therefore when zooming ...