Questions tagged [qgis]

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

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14 views

Stop QGIS opening multiple taskbar items?

I have QGIS pinned to my taskbar, right clicking shows that it's named "QGIS Desktop 3.8.2". When I run it and open projects some of them open a new taskbar item called "QGIS 3". This also happens ...
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12 views

Adding information to layers in group (QGIS)

For a QGIS plugin I want to access the layers in a group called 'Drawings'. For this I want a ComboBox with the list of layers. I tried different methods but can't get past the fact that i am refering ...
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14 views

QGIS forms : field display based on the value of another field

I have a form designed in QGIS 3.8.1. The form is associated with a layer for inputting data. Many of the fields on the form are only relevant if the first field is equal to True. Example: Field 1: ...
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1answer
16 views

How to import CLR in QGIS python?

I created a plugin and I added my separate python file(added in plugin path itself) in the created qgis plugin. In that separate python file, I called a DLL file like below, import sys import clr ...
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1answer
29 views

Managing PostGIS default privileges for users in QGIS?

I have a PostGIS database for several projects, most of which we work with in QGIS. Each project has it's own schema. For each schema I have created a group role project-members, where project is ...
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28 views

Spatial distribution of vector polygons

I have two vector layers and I am looking for a tool for spatial distribution of the polygons. polygon 1 is the frame, polygon 2 are objects with different size and distribution. I need an index value ...
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23 views

Correction of GPS-Track, snap to road (line, network)

Problem as shown in the image: I like to correct the GPS track (orange) to the right road (black). In a network of roads it is difficult to snap to the right path - for human it's obvious which one ...
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1answer
29 views

In QGIS: NetCDF image too pixelated

When i import NetCDF file (.nc) to QGIS then I get a picture that consists of quite big pixels. Is it somehow possible to soften those pixels to get something like this:
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1answer
35 views

Merging lines based on distance from point in QGIS

I have 5 groups of 4 lines, all the lines in all the data sets are centred around the same point. I need to algorithmically combine these lines into one line that is only the furthest from the point. ...
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23 views

QGIS map legend rendering problem

The maps look good, and the legend symbols match the maps. Once converted to .pdf the map legend symbols degrade to basically nothing. Horizontal red line patterns, or any colored line patterns for ...
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58 views

Updating large Shapefile with new polygons

In QGIS I have a multipolygon layer that has about 100 polygons in it (property boundaries) and I will need to continually add polygons to it as they become available. What is the most efficient way ...
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23 views

How to custom format my coordinate grid?

I am custom formatting my coordinate grid. Is there a way to change the following formula so that the output comes with a decimal and suffix: substr(@grid_number, length(@grid_number) -6,5) The ...
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23 views

Transferring layer files from ArcGIS Pro to QGIS

I have access to ArcPro at my workplace and will be transferring a project over to someone who will be using Qgis. I have saved my layers as a layer file but the problem is that the other person is ...
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1answer
16 views

Exporting NetCDF layer with defined colors using QGIS?

I have average wind speed NetCDF file (.nc) that I imported to QGIS. Then I defined colors for wind speeds in equal interval (3, 3.5, 4, 4.5 etc). Now I would like to save this colored map for sharing ...
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26 views

Displaying QGIS's “Map Tips” in OpenLayers?

Still a little new to QGIS and Openlayers. How would you display QGIS's "Map Tips" into OpenLayers? I am currently using QGIS 2.18 and have the latest update in Openlayers. In QGIS, I have created a ...
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1answer
14 views

(QGIS) Shapefile with attribute table: Convert it to raster burning values of each polygon to the raster. “Heatmap”

I am working on QGis with a shapefile with an attribute table, I have created this shapefile through "Vector->Analysis tools->Count Points in Polygon", so this new shapefile got the count in the ...
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1answer
30 views

How to get the type of the largest polygon inside a grid cell?

(1) I have a vector grid layer. (2) I have a multipolygon layer. Each polygon has a specific type (in this case a vegatation type) Now I want to get as an output the grid layer where each cell ...
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21 views

Point Geometry doesn't have X and Y values and prints (0,0) as it's coordinate but overlays properly on satellite imagery

I have downloaded a point layer which is in the projection WGS84 as per it's .prj file. It also displays properly on the map and when I hover over points it shows the correct lat long. But when I ...
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18 views

Connecting QGIS 3.4 to a MS Access database

I try to connect to MS Access and i have already created an ODBC connection. Now, I have the the problem that I cannot open the database in QGIS (but the connection was succesful).
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40 views

Splitting layer with many polygons into independent shapefilles? [duplicate]

Is there any way to save many shapefile, which are not multipolygons, into shapefile, and then iterate over them? I have shapefile with plot polygons and I want to have each one independent in order ...
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22 views

Batch process aligning multiple rasters in QGIS

I would like to know if there´s a way to run a batch process that consists in aligning (changing cell size from 10 to 20 in Sentinel 2 imagery) in QGIS 3.4? I need to resample band #8 (resolution 10m)...
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1answer
32 views

Problems with analyzing MODIS Aerosol Optical Depth

I want to extract AOD from the following hd5 file.Would be grateful for any help. Objective is to have a tif file projected in EPSG:4326 with values of all 3 bands. https://e4ftl01.cr.usgs.gov/MOTA/...
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22 views

Change the azimuth of Graticule lines

I have created polygon graticule and I used ''polygons to lines'' to change the polygons into lines. I want to change their azimuth to make them more feet into my polygons. I had the idea to calculate ...
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29 views

PYQGIS 3: Processing Toolbox, output vector & raster layers

I figured out that besides from the python editor within QGIS, the layers that I'm creating in my .qgs projects with a Processing Toolbox are not saved and displayed. --> see image: 1) what I get ...
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14 views

Nearest Neighbour along a route instead of geographical displacement

Say that I have three layers as follows for a certain region: Line Layer representing roads Point Layer representing hotels Point Layer representing train stations Using QGIS is there a way in which ...
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1answer
25 views

Show/mark not visible labels (colliding labels)

If "show all labels, also colliding" is not active, some colliding labels will not show up. So far so good, but I would like to know, how often and where this happens and maybe why. Something like a ...
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1answer
37 views

Adding points randomly inside a polygon from an attribute table to a different polygon layer

I have two layers: 1. One with polygons geometry 2. CSV table with more than 600k rows They have an atribute ID in common, so, I want to distribute randomly each row, inside the polygon as a point. ...
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44 views

Switch from 3 to 3.8 for QGIS [on hold]

For QGIS 3 there is a plugin called open layout, I have installed 3.8 and what is the QGIS 3.8 plugin called, for open layout?
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23 views

Categorizing joined attributes using QGIS 3.8.2 Zanzibar [on hold]

I have a joined layer that has 119 attributes. I want to categorize them into quintiles (5 equal groupings). How do I do that? I can't seem to find anywhere online that addresses how to do that using ...
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20 views

Drawing lines between points in a shapefile that are related to each other

This is a more general question, wondering if it is possible. I want to make a map of all the organizations in my city and which ones partner together. I imagine I would make a shapefile that is a ...
3
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1answer
39 views

Nearest line to polygon based on equal attribute

I have a polygon shapefile and a line shapefile with several thousand features each. I want to get: The nearest distance between a polygon and a line that have the same attribute (e.g. ID). Example ...
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15 views

Selecting text characters within a string, or multiple field characteristic results as independent values? [duplicate]

I'm working to map data out using information extracted from a database where values were input based on characteristics assigned by a reviewer. I'm looking at mapping characteristics of a building's ...
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37 views

QGIS 3.8 labels placement

On my layer the setting of the labels is: But all the labels do not appear, as if there was a limit on the number. Sample with some features Sample with all features: some labels have disappeared ...
3
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1answer
52 views

Calculating the number of days between two dates as number

For some expression in QGIS I need to get the number of days between two dates as numeric value. If I substract two dates I get an interval back: to_date('2019-12-31') - to_date('2019-01-01') gives ...
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1answer
56 views

Difference between $x and x($geometry)

I just stumbled across something weird: I had point-data in EPSG:3059 and wanted to add the coordinates to the attribute table using $x resp. $y - which returned NULL. x($geometry) on the other hand ...
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21 views

How to create a raster map in QGIS that includes the distance to the nearest road multiplied by another variable included in a vector file?

I am using QGIS (v. 3.4). I have a vector file (.shp) with the main roads of my city including the average traffic load of each segment. I would like to create a map with the inverse distance to the ...
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1answer
28 views

Problem with ''Split lines by points''

I'm trying to use the SAGA tool ''split Lines by points''. I have created the line layer using '' Polygon to lines'' My goal is to split the lines. I created points using Extract points I want to ...
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1answer
55 views

QGIS Project saved in PostgreSQL not loading on other computers

I have created QGIS projects that are reading from PostgreSQL(data source). I then saved the individual projects to PostgreSQL in the public schema under their respective databases. When I open or ...
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21 views

After creating tiles in QGIS by enabling VRT, I'm getting black color tiles [on hold]

I have a big TIFF image and I created tiles of size 512 X 512 but all the tiles colour is black I don't know why.
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1answer
46 views

QGIS report composer to show related tables

Is it possible to include in the QGIS report composer a fields group section with tables that are related on a 1 to many relationship? For example a point layer "HOUSES", with a KEY that relates to a ...
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2answers
42 views

QGIS Raster Georeferencer adds black padding to corners of adjusted black and white TIFF image

After georeferencing a black and white TIFF image, the QGIS Raster Georeferencer fills the corners with black pixels, creating black elongated triangles along the edges of the new image. I could not ...
3
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1answer
47 views

Finding sum of points values within distance from paths

I'm willing to plot public transport data for a university project, and I'm currently trying to find out roughly how many people live with a reasonable distance from a set of bus routes. I have my ...
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37 views

Getting complex CAD drawing to right location in QGIS?

I have a complex CAD drawing from a city with many layers..hatches, points, poliylines..and I need it to georeference because when I import the DWG file into QGIS it turns out to be at the wrong place....
2
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1answer
60 views

Making colored hillshade in QGIS?

Today I found that ArcGis can make colored hillshade like on piture below. Here is link to their blog. I want to do that in QGIS. I know about layer coloring feature, and it's close for perfect, but ...
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1answer
34 views

River network from DEM

Anyone who know if there is a method of creating rivers network from digital elevation model in qgis as it does in contour.
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30 views

Shift points onto a line in QGIS 3.8

I am working on some poorly digitized data, which I am cleaning up. Using the topology checker I find that a large number of points do not sit directly on a line as intended. They seem to be of the ...
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17 views

Problem with encoding after using ''join by location''

I used Join by location and for some reason the results I get have weird encoding, i have checks and it's UTF-8, how can I solve it
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26 views

Least Cost Path in QGIS: Plugin or SAGA or GRASS?

I downloaded a SRTM file and followed this tutorial and now I have a hillshade layer and a color layer. It looks like this. I want to calculate the least cost path between p1 and p2. But I'm not ...
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1answer
42 views

QGIS 3.4 Rule Based Symbology - Exact Matches Integers in String e.g. 2,12 + 1,2,3,12

I have a shapefile containing a String Type Field called 'Class'. This field contains one or more integers separated by commas. I want to create Rule-Based symbology matching only 2, 12, 1 ...
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34 views

How to QGIS least cost path analysis [duplicate]

I want to do some least cost path analysis and I followed this website. Now I have a hillshade layer and a color layer. Is this enough for least cost analysis or do I need something else? And if it is ...