Questions tagged [qgis]

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

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Convert EPSG::4326 degrees to km, given coordinates

I have the following data structure pointid distance lat long where pointid is a list of points, distance is distance of point from feature (calculated in QGIS in geographical units under a EPSG::...
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60 views

Generating bus network segments between stations

I have a network I downloaded from OpenStreetMap. I created bus station points on it and I want to create segments between each two successive stations, each segment with a start_station & an ...
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369 views

Clipping land cover grid with shapefile in QGIS

One very common application of GIS to ecology is to layer a set of vector polygons over a land cover grid (or some other land feature raster) and clip it to determine the percentage of the cover ...
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1answer
81 views

Using r.reclass.area.lesser in QGIS?

I want to reclass small areas in QGIS 2.18, but it seems to fail calling the algorithm in GRASS GIS. The interesting lines from the Log of the tool: ... C:\PROGRA~1\QGIS2~1.18\bin>g.region n=...
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81 views

dbvalue functions don't seem to be working on QGIS3

I've brought a project with some virtual columns into QGIS3, but the formula with dbvalue functions (from the refFunctions plugin) in doesn't seem to be working any more. It just gives NULL values. ...
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1k views

Plugin install failed in QGIS 2.6

I've been using QGIS 2.6 and whenever I try to install some plugin through plugin manager, it returns an error "Plugin installation failed:SSL handshake failed". I have always had to manually install ...
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206 views

QGIS not importing correct IPython version for IPython QGIS console plugin

I am trying to run the Ipython console plugin in QGIS 2.18 After installing the plugin, I tried running it, and got the following error: You need to install IPython 3.1.0 (and then restart QGIS) ...
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137 views

QGIS crash: delete column in GeoPackage

QGIS crashes without error or log massage as soon I try to delete a column in a GeoPackage using the attribute table: How could I find out, what's going on in background of QGIS? Installed QGIS3 on ...
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110 views

Fixing digitized map using QGIS?

I have some cartographic maps I need to fix the position/digitizing. If you look on the below image you will see that the point layer is not exactly at the center of the map. The exact center is ...
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1answer
400 views

Broken colors or black background with OpenLayers Plugin in QGIS

Approximately last few months I am experiencing problems with OpenLayers plugin in QGIS - especially with OpenStreetMap data. The layer loads sometimes terribly slowly although the connection is ...
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78 views

Fast implementation of polygon overlay tools in osgeo suit

I am currently using symmetrical difference, difference and intersect tools from standard QGis implementation in python (I use pyqgis). I do topological checks ie. if Fc1 is contained within Fc2. ...
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338 views

QGIS: How to plot a GPS track color-coded by the altitude (or any other value like speed, …)?

I have GPX files recorded from various treks. I want to plot them on a QGIS map and have the color of each track segment modified by the altitude recorded. An idea of the result I am looking for is ...
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2k views

Creating a distance matrix for line and/or polygon layers?

At 2.18.16, the QGIS tool Distance Matrix computes pairwise distances between all points, either within one layer or between two layers. Here's a screenshot for a single layer. Note that only points ...
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1k views

QGIS export to KML

How can I create this kind of output in Google Earth from QGIS, where I can show the labels of the exported file in KML?
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120 views

Change of data type after exporting from PostgreSQL to shapefile

I had loaded shapefile created in QGIS 2.8.9 with following data type in PostgreSQL as shown in image. After import the shapefile in PostgreSQL the data type shown as below. When I export the data ...
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138 views

QGIS crashes when adding ArcGIS FeatureServer Layer

I want to add an ArcGIS FeatureServer Layer into QGIS. I can add the layer sucessfully but as its being downloaded if I ask QGIS to do anything else it crashes. First I bring up the Add ...
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144 views

Making base maps for weather limited to exact space and output dimension in QGIS?

I need to make some pretty basemaps and wish to use QGIS. The program which will use the basemaps is GrADS, which doesn't read any navigated imagery like geoTIFF or kml. However it produces KML ...
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374 views

QGIS - Bad Allocation error message on zoom or atlas generation

I've seen a few topics on the 'Bad Allocation' error message, but nothing that's help solve my problem yet. I have a virtual layer returning records from multiple tables, but I can't identify any of ...
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372 views

GRASS processing tools on Mac “ERROR: Sorry is not a valid option”

using Qgis 2.18.15 on Osx I have some issue using the v.net.iso tool. I launch the tool, but got no result at all. I can see the process goes by but no new layer at the end Any idea? Code in ...
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143 views

Selectively install frameworks for macos QGIS?

The KyngChaos method is the one-stop shop for Mac users to install QGIS. This page has links to the critical frameworks and python modules, which he graciously packages and maintains himself. Have ...
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1answer
446 views

Overlaying a .png image that comes with a world file in UTM with OpenStreetMap data?

I have received a geocoded .png image (2380 x 2396 pixels) that comes with a world file containing georeferencing information in UTM format: worldFileParams = [0.5,0.0,0.0,-0.5,690920.0,5335407.5] ...
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390 views

3D globe from GIS data (QGIS shapefiles or PostGIS)

I'm looking to create an interactive 3D globe (in Unity 3D in case it matters) that gets its data from a GIS backend. I'm using QGIS as my editor and I can store the data in shapefiles or PostGIS. All ...
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172 views

How to set a custom position for Atlas pages in QGIS 2.18.14

I want to set a position for each page/feature in the Atlas. For scale and rotation I resolved here: Set a custom maps rotations for specific pages in the print composer in QGIS But now, I can´t ...
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43 views

My layer won't appear in QGIS using PostgreSQL 9.1

I am working with a "cities" layer (polygons) in a PostgreSQL 9.1 database. When I use the following query in PostGIS: select st_buffer(st_union(st_centroid(cities.geom)),1500) geom from "my_layer" ...
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104 views

Python Console XML creation - Not releasing memory?

I have created a module to prepare an XML file. Since xml.etree does not output a pretty XML I use dom. ****Module:**** from xml.etree import ElementTree from xml.dom import minidom ...
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1answer
255 views

How can I set sde object id from QGIS

I have connected a geodatabse that was created by ArcGIS. My geometry type is PG_GEOMETRY. I can connect the database in QGIS and add a feature table as a layer. When I create new spatial data in this ...
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374 views

Align two georreferenced rasters which have different resolution in QGIS

I have two rasters in .TIFF format which have different resolution, different information and extent but georreferenced in the same coordinate system . I would like to know if it possible to align ...
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1answer
140 views

QGIS - Script for Process Modeler, Output = Extent

just played arround a little bit with the process modeler and scripts to automate a simple workflow. I have created a simple script that should get the extent of the current layer, and then increase ...
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581 views

Preparing SRTM (hgt) for use in SAGA GIS?

I am trying to prepare a raster file which i could use with SAGA processing tools for hydrologic analysis in QGIS. I am using Win 7, 32 bit, QGIS 2.14.20 and SAGA 2.3.2 I downloaded the srtm file in ...
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476 views

Export AutoCad 2017 layer (with lines, blocks, and text) to GIS shapefile

How can I convert (export?) a DWG block into a GIS shapefile so that the block's insertion point will become a point in the shapefile and the block's text attribute will carry over as an attribute in ...
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91 views

How to use *.tf or *.tfi files in QGIS?

I have some data in a deprecated projection that might not have an EPSG code. I I have asked the provider to tell me which coordinate system is and the answer come with those file, probably to use FME....
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547 views

How to display a Google Maps with Qt + QGIS

I am developing an application with Qt + QGIS. It will have a map component to be rendered by QGIS. The map needs to contain a base layer with Google Maps tiles and additional layers with data loaded ...
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456 views

QGIS install failing with dpkg errors/

QGIS stopped working with this error: /usr/lib/qgis/crssync: symbol lookup error: /usr/lib/libgdal.so.20: undefined symbol: GEOSDelaunayTriangulation_r I removed/purged everything for a fresh ...
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5k views

Creating waypoint coordinates on a grid within an area

Do you know which GIS software or online tool supports returning GPS coordinates on a grid within an area? Kinda like waypoints for drone photographing 90 degrees looking down of an area for 3d ...
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78 views

Qgis Sentinel 2 black images

I am working with Sentinel 2 bands in Qgis 2.18. When I load them to Qgis' TOC, they appear in black and in the layers panel they do not display the minimum and maximum number of pixels. I would like ...
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116 views

GRASS plugin not working properly

So I've been trying to make a master cost raster (taking into account the slope and landcover data). However I can't make the r.mapcalculator work... I tried with r.mapcalc but the interface looks so ...
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431 views

QGis missing osgeo python-gdal, Python 27 vs Python 36

I have trouble while installing QGis from scratch on a computer that already have Python (3.4) + GDAL bindings. Here, QGis works with Python27, that needs its own GDAL bindings : how can i deal with ...
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1answer
288 views

Calculating distance between pixel values on raster layers using QGIS

I am attempting to perform a proximity analysis to determine the distance pixel values on different rasters layers. For example, one layer is roads (with all roads having a value of 1) and one is oil ...
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52 views

Get lines surrounding a point

Assume we have a road layer and we have a specific point and want to get all roads that surround this point or more precisely form the closest polygon around that point. I miss a good approach - is ...
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1answer
217 views

Filter diagrams with atlas coverage layer in QGIS

Please advise how I can hide diagrams outside of the coverage layer when using QGIS atlas function. I can do this for polygons,rasters etc without problem but whatever I do I cannot hide diagrams from ...
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19 views

QGIS swaps(?) attribute tables of PostGIS layers

I have a QGIS project (2.18.14 Win10), last saved yesterday, with several PostGIS layers. As I opened the project today the PostGIS layers did not display on the map (but appear in the Layers Panel). ...
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237 views

Coloring service area using QGIS and GRASS tool v.net.alloc

I try to work with v.net.alloc to find some service area for my problem in QGIS 2.18.13. That algorithm work nice create categories from my roads for any hotspot like this : and if use style ...
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312 views

MSSQL Spatial vector features not showing up in QGIS 2.18 up

I'm importing a MSSQL 2008 Spatial layer in QGIS. In version 2.14 it works OK, I can see the vector features and interact with the associated attribute tables. But in versions 2.18 and 2.99, though ...
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149 views

Google Basemap doesn't align with data after export

Help! I put together a map in QGIS and everything looks good in the composer view, however when I export to PDF, the projection/data seems to have shifted from the Google Open Layers basemap. I ...
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197 views

QGIS visible window rendering

Is there a way of changing the rendering settings on QGIS so that only the visible map extent renders? It seems that all layers are rendered to the full layer extent. I'm trying to speed rendering up ...
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80 views

Finding River Lots in Alberta, Saskatchewan and Manitoba using QGIS?

I have to border farmlands in Canada (Alberta, Saskatchewan and Manitoba). Usually they give input in the form of DLS like SE-9-56-22-W4.So I use https://locator.scadalink.com/dls2latlng.html to find ...
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179 views

Geoserver MultiGeometry in KML

Is there a way to get line and polygon data without the MultiGeometry Wrapper from a geoserver layer when accessing via the KML Reflector method? It always generates additional Point data for Lines ...
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18 views

adding a Layerdefiniton file in QGIS 2.99

Wouldn't it be better to add the possibility of adding a Layerdefiniton file into a QGIS-map to the new Data Source Manager?
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127 views

Manipulating / modifying terrain data to model a new surface

Short question: How to (intuitively) modify/manipulate a terrain with QGIS or alternative Open Source Software? The details: In order to build a habitat (ponds and depressions) for amphibians, a ...
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88 views

Automatically name rectangles by spatial order or position to each other

I need a solution for that case: I have got a fishnet-raster (as polygons) without any systematic order in the ID of the features and need to label every rectangle from A1 to F6: For now I do it ...