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Questions tagged [qgis]

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

0
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1answer
41 views

QGIS color map format

What is the correct color map format (.txt) for a color map I want to load in the Raster Layer Properties/Symbology menu of QGIS (v. 3.6.0)
3
votes
1answer
48 views

Calculating twists/turns of vector line using QGIS?

I currently have a large layer (trails) and want to calculate for each trail how much the trail turns or is distorted between the start and end of the trail. Is this possible on QGIS 3.6.2?
2
votes
1answer
81 views

Finding centre line of irregular polygons with QGIS?

I have a set of irregular and curved polygons which I would like to find the centre line of them. I've found some solutions for this problem such as Voronoi polygons but It doesn't work for me. It ...
9
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3answers
920 views

Voronoi Diagram on a given polygon using QGIS

I am trying to create a Voronoi Diagram on a specific polygon, but there is some issue when dealing with edges. Here is how I do it: Preparing the points for Voronoi and the polygon for the diagram ...
0
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0answers
16 views

Creating calculated field in Raster layer using QGIS?

I have a NetCDF file (http://rs-data1-mel.csiro.au/thredds/catalog/bawap/rain/day/2017/catalog.html?dataset=bawap/rain/day/2017/bom-rain_day-20170201-20170228.nc) which I have imported into QGIS (...
1
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0answers
33 views

Adding updates to current QGIS version from later ones?

I am currently using version 3.4 of QGIS, and I was wondering if it is possible to implement all of the awesome changes from version 3.5, 3.6, etc. into version 3.4 or do I need to keep installing the ...
0
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0answers
11 views

Access WMS layer diffused through ArcGIS Server in QGIS

I am having an issure regarding the consumption of WMS service in QGIS (Version of my QGIS is 3.6.2-Noosa). My WMS Service is being diffused through ArcGIS Server 10.3. When I access my WMS ...
0
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1answer
41 views

Replicating Conditional popup of ArcGIS Online in QGIS2WEB?

I stumbled across this ESRI post about Conditional Field display with Arcade in Pop Ups. I am not well versed in HTML, but I could follow along well enough to understand the post. However, how would ...
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0answers
37 views

Is there maximum number of points you can import from CSV to QGIS 2.18

I tried to import a CSV file which contains 4,783 rows. However, only 20 records appeared. Any one has solutions to solve this situation? How can I add all rows in QGIS delimited layer? PS: I use Mac ...
0
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1answer
32 views

Forcing color ramps to center around zero in QGIS

I have several columns of data that have percentage values. Some are positive and some are negative. In one particular column, the values range from -0.70 to +0.20. The mean value of the column is ...
1
vote
1answer
34 views

Intersecting 2 layers without creating duplication using QGIS?

I have 2 polygons that i wish to combine into one layer, in QGIS. on the first layer (neighborhoods) i have bigger areas (that divide a city to 7 major areas, or smaller neighborhoods). that i wish ...
1
vote
1answer
23 views

Determine QGIS version in a startup script that PYQGIS_STARTUP points to

The environment variable (Win10) PYQGIS_STARTUP points to a python script that is executed before QGIS starts (cp. Central deployment of startup.py in QGIS). Now I need to determine the QGIS version ...
1
vote
1answer
30 views

Exporting to S-57 basefile using QGIS?

I want to export layers in QGIS as a S-57 basefile, but can't get it to work. Is there any documentation available regarding the processing parameters? I get error message when i try to export, ...
0
votes
1answer
26 views

Using gdal_translate for multiband raster to convert into .XYZ file? [duplicate]

I have raster containing 2 bands (NDVI and DEM). This raster was created in SNAP using "Add Elevation Band" option, "DEM Model:SRTM 1sec Grid" to the NDVI product I had generated earlier. I could not ...
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0answers
25 views

Displaying raster images vertically in QGIS 3.x (Geological cross section)

I'm aware this has been asked before to an extent, but the answer here doesn't really cover raster images. I want to 'hang' a raster image in 3D alongside a surface. The raster is a geological cross ...
-1
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2answers
37 views

Seeking nautical charts for ArcGIS Desktop and/or QGIS? [on hold]

Where can I find nautical chart data that I can read in ArcGIS Desktop? I am basically looking for world wide commercial data (free is fine too of course) with a focus on Europe. Can be vector or ...
0
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0answers
29 views

Using relative path in QGIS 3.x processing modeler? [duplicate]

I try to use a relative path for the algorithm "Set style for vector layer" in the processing modeler, but it works only with absolute path. A similar request is here, but the answer doesn't suit me. ...
1
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0answers
40 views

Selecting polygon as Input in QGIS Modeler?

I need to create a model where I select two polygon and the first one is clipped with the second one. Difference function is doing it. But asks for two input layers. How can I add as Input a Polygon ...
0
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0answers
9 views

Dump with QMarxan Toolbox

I have a problem with QGIS 2.18 when I use the QMarxan's toolbox ... Everytime i use it, it dumps but create a file (shp). I believe it is a problem of writting when it is supposed to transform the ...
0
votes
1answer
35 views

QGIS 3 How to Create Glow on Layer with Gradient Symbology

I have a line layer (street network) coloured with a gradient scale based on certain attributes. I would like to add a glow effect from the draw effects properties option, however the glow can only be ...
0
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0answers
39 views

Converting QGIS layer to Gephi?

I want to convert a QGIS layer to Gephi. Im not sure what steps I need to take to make this happen. Currently I have a layer with numerous trials (edges). And I will be using water holes as nodes. ...
1
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0answers
19 views

Creating buffer around points (layer + map in the same PCS)?

Currently creating a map of fire stations in LA and want to create a 50-mile buffer around them. My project right now is in NAD 27 / EPSG:26799 (Projected CS). I also managed to save my shapefile with ...
2
votes
0answers
32 views

Multi-ring buffer (Constant distance) selecting features in another layer

I have used the multi-ring buffer to form a buffer area of 10, 20, 30, 40 and 50 metres from a road. However I am struggling to select features from another layer (trails). My aim is to count all the ...
0
votes
1answer
24 views

Adjusting QGIS 3.6 Print Composer default output resolution? [duplicate]

When exporting a print layout to image or PDF in QGIS 3.6, the default resolution is 300dpi. I'd like to change that default. There's an analogue question here: Adjusting QGIS Print Composer output ...
1
vote
1answer
53 views

Getting Canada shapefile to overlay model on QGIS?

How can I get Canada to overlap with the rest of my map? I think this is a CRS problem but I really do not know how to solve it.
1
vote
1answer
34 views

Map based on highest percentage from different variables

I've the 8 social classes (see under) for +- 900 polygons. I would like to create a new column that keep only name of the main social class for each row (based on the percentage). After that I would ...
1
vote
0answers
45 views

Getting error message in QGIS field calculator?

I have used an equation within the field calculator, that has previously worked in an older version of QGIS, I am currently using QGIS 3.6.2 the equation being: (atan((xat(-1)-xat(0))/(yat(-1)-yat(0))...
7
votes
3answers
152 views

Creating hundreds of maps showing different layers but same area using QGIS?

I want to create bird species location maps for a single area (and there are multiple areas). There are a lot of species, every one needs an individual map, so I'm facing 100+ maps per area. Is there ...
0
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0answers
20 views

GeoServer could not show the layer by SLD style

I am trying to show simple classification of semi real-time data by using PostgreSQL v.1.20, QGIS 3.4, and GeoServer 2.15.1 The idea is symbolized the field of 'Statusparkir' in table parkir_conn. ...
0
votes
1answer
16 views

How to keep color changes / corrections of all GeoTIFF files during merge with gdal or in QGIS?

I am trying to merge two GeoTIFF files in QGIS or w/ gdal, but when I merge them I lose the color changes / corrections I made to the second GeoTIFF. Is there any way to keep the color changes I made ...
1
vote
1answer
30 views

Selecting the name of the raster layer for each point in a shapefile (QGIS)

I have multiple raster files (i.e. elevation in the United States) and over 300 points in a separate point shapefile. Each point lies in only one raster file. I'd like to be able to find out the name ...
0
votes
1answer
25 views

QGIS manually select overlapping features/data points

I am trying to manually select features visualized on a map to change an attribute of several features at once by highlighting them on the map using the "select features tool". I'm using the multi ...
0
votes
0answers
22 views

How to manually input decimal value into z-coord in QGIS

If I want to manually input a decimal value to Z-coord in QGIS, there's no effect. Only integer values are saved in nodes editor. Operating system Ubuntu 18.04, QGIS 3.6, locale: poland, data and ...
1
vote
2answers
39 views

QGIS API to determine number of walls an AP intersects

We are trying to identify QGIS API which can determine where all does a ray of signal intersects in a given room. See image for reference. What we are looking for as result is "the lat lng of all the ...
0
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0answers
15 views

Are the *.env and *.var files neccesary for QGIS3

I asked a question about how to make sure that QGIS3 is always started by calling the qgis.bat file: Check whether QGIS3 was started by qgis.bat or qgis.exe One idea was to intentially break the ...
3
votes
1answer
55 views

Making a custom expression “portable”…?

In a QGIS project im using a custom expression. As far as i know they are stored locally in a .py file located in the user profile. What would be the solution to make this custom expression "...
2
votes
0answers
40 views

Calculating share of overlapping areas via aggregate function in a virtual field

I'm trying to calculate the shared area for several overlapping areas. I need a dynamic solution in order to get automatically calculated statistics when drawing new polygons. The target area is in ...
3
votes
0answers
35 views

How to plot distances distances in meters in QGIS?

My goal is to plot circles on QGIS canvas by taking distances in kilometers from MySQL base. This is code I use: from PyQt4.QtCore import * from PyQt4.QtGui import * from qgis.core import * from qgis....
0
votes
0answers
12 views

gdal_warp cannot specify target extents

This is related to this previous post. As was trying to implement the said answer and inserting it to my code, but the code doesn't seem to work. #importing all the necessary modules import os, ...
5
votes
1answer
79 views

Showing feature count for layout extent on legend using QGIS?

I'm using QGIS 3.6.1 on Win10. I have a print layout with a map of an area within my total work data set. I add an item to the print layout legend with the summation button on for "Show feature ...
2
votes
2answers
93 views

Get attributes from touching lines in network - results seems random

This question is similar to this one: Get attribute from touching line layer (QGIS) but there is a new and more komplex problem in that context I need to solve: I have to plan drains, usually along ...
1
vote
1answer
33 views

QgsApplication.processingRegistry() loads providers however is empty when called in within class function

I am in the process of building a standalone interface to QGIS to use the processing functions. In essence I am creating a mainWindow GUI with a Qgsmapcanvas. The GUI also includes some user inputs ...
1
vote
0answers
29 views

QGIS Python AttributeError object has no attribute 'pushVersionInfo'

I am unable to use almost all of the processing toolbox features in QGIS. I keep getting the following Python error across multiple algorithms: AlgorithmDialog.py", line 208, in runAlgorithm self....
0
votes
0answers
26 views

Applying symbology to Folium (Leaflet) polygon layers

I am trying to create a Folium map in Python that includes multiple polygon and line layers. I would like to be able to change the symbology of each layer to differentiate it from the others. I've ...
2
votes
0answers
33 views

QGIS print layout (large size printed image)

I have been asked to create large size images to be the printed with a good quality to look at. The images could be with dimensions of 1 meter in height or width, but even larger. I must create these ...
1
vote
1answer
27 views

How to change projection to lat long from eastings and northings, QGIS

I'm using QGIS and I'm trying to get the coordinate system into lat/long instead of eastings/northings. I think I'm choosing the correct coordinate system, but my "Extent" is listed in eastings/...
1
vote
0answers
18 views

Problems with LecoS plugin in QGIS on Mac Mojave

I wanted to install LecoS plugin in Qgis. But first error appears that I have to instal scipy for python in orderd to use plugin. Python was instaled using instructions from Qgis document, version 3....
0
votes
0answers
26 views

Polygon problem with Wacom on QGIS

I currently have a problem on QGIS with my Wacom tablet and polygonal tools. When I create a shape with the polygonal tool, if I use my Wacom tablet, the cursor moves well, but the path (red dotted) ...
2
votes
2answers
157 views

Adjacent DEM color matching in QGIS?

I have four 15 arc second resolutions DEM files (15-C.tif, 15-D.tif, 15-I.tif, 15-J.tif) downloaded from viewfinderpanoramas.org. When I input them in QGIS I noticed that the 15-J.tif layer differs a ...
0
votes
0answers
14 views

QGIS Heat map Agent

So I have a city lets say London and I've imported the location of houses in London and roads next to those houses and calculated the nearest distance point in meters and have it as a layer. Now my ...