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22.223 qgis questions.

How to performe Exact Large-Scale Mean-Shift segmentation in Orfeo on clipped and preprocessed Landsat 8 image in SCP plugin (dos 1 atmospheric correction)? How to determin segmentation parameters?

I'm trying to make a simple stand-alone app to expedite the production of some site plan maps for my work. The maps are very formulaic, and follow a set template every time. With the QGIS libraries, I ...

When I started building a database in Midvatten I followed the tutorial: https://github.com/jkall/qgis-midvatten-plugin/wiki/Tutorial This tutorial suggests for setting up a new database: "When ...

I want install several versions of QGIS with OSGeo4W Network Installer (2.18, 3.0 and master). Will it be good if I install it in one root direction or should I create separate folders?

I have an Esri shapefile with following in the .prj file (broken into multiple lines for comprehension): PROJCS[ "SGL_Stereo", GEOGCS[ "GCS_SGL_GEO", DATUM[ "D_SGL", SPHEROID["...

I have created a series of buffer regions around line segments in QGIS (in my case a road network): The buffers are in transparent blue with the darker circles being where the buffer segments overlap....

I want to recompile qgis_app.dll from QGIS 2.18 with some of my changes. Cannot find project file for this library in repository. And what is the best tool to do it? Qt Creator or Visual Studio or may ...

Ever since upgrading to QGIS 3.2.3 I have had numerous errors. The latest which I cannot seem to resolve is the following: I am trying to run classifications using the semi-automatic classification ...

I've got an atlas in QGIS 3.2 and also 2.18. There is a main frame showing a map with points. Underneath there is a table with further information about the points. If there are many points, the ...

I am trying to run the following analysis in QGIS 3.2. My inputs: raster layer (with population estimates from LandScan) vector layer, with points (each point represent the location of a mobile cell ...

I'm using QGIS 2.8.1 Atlas and creating a mapbook using a grid layer that has an attribute with a URL in it. I want to use the URL in the attribute to be a hyperlink in the PDF once its published. ...

I work in architecture and we often have to create urban contexts for our projects which involves obtaining a building footprint file and then extruding them by hand. I have attempted to use QGIS (v3....

How can I get the wkt from a geometry object in python? I'd like to be able to do something like the following: from qgis.core import * import qgis.utils layer = qgis.utils.iface.activeLayer() for ...

General description: I am using QGIS as quick visualization tool, where I make a "PostGIS" database layer and I see user generated events. Table structure as follows: Id | time_of_event | ...

I am trying to get information from a QGIS project and layers and produce a new project based on new analysis results made on FME. How to install the PyQGIS module and then using the custom python ...

I'm delineating some coastal subbasins using open source software. I have asked a similar question before (Delineating coastal subbasins using SAGA GIS or GRASS in QGIS?). I found that using SAGA Fill ...

I have a polygon layer with 3 fields (A, B and C). I want to create a copy and add as a virtual layer so I use CREATE VIRTUAL LAYER option but only want the first field. So I use the expression ...

The raw data would be like this: I want to create a streamgraph with the width of the polygon being the amount in the certain date for the certain purpose, the output should be in shapefile format : ...

I need help with this problem QGis 3.0 to MacOS HighSierra. When I start QGis 3.0 its show this message. first message... ModuleNotFoundError: No module named 'osgeo' Traceback (most recent call ...

I am trying to draw a polyline from a single reference point. I have each specific segment of the lines Azimuth & distance. In the sequence I have areas where my line shifts over +90 / -90 of the ...

I have a continuous value raster which appears to be correlated with attributes from multi-line vector data. The lines are transects intersecting the coastline and the raster represents data just ...

I'm using the QGIS Warp (Reproject) tool to reproject a raster from WGS84 to a Lambert Conformal Conic custom projection in QGIS 3.2.2. The call to the GDAL/OGR console is the following: gdalwarp -...

I have a building Layer(Full of Polygons).I want to get centroids of polygons and save them as point layer.I am using python console within Qgis 3.0. I have tried below code.I got my Centroid Layer(...

I'm trying to get PyQGIS running with the reticulate package in R. Below, I set all the environment variables I would usually set before running a Python script that uses PyQGIS. Using this setup, I ...

My QGIS project has multiple layers. I use a U.S. county map as my base, and higher-level layers have lines. When I use the simpleSVG plugin to export my view to an SVG, then open the file in a web ...

Is there any reason why QGIS swap axis order if CRS (EPSG:3908) is defined inside GML, for example, <au:geometry> <gml:MultiSurface gml:id="_42d05737-123d-4a52-a655-aef968cd9511" ...

In QGIS, I want to discern between a number of building types, based on topology. I have data on buildings, parcels and addresses. I'm having a hard time to discern between row/terrace, end-of-...

I would like to use a startup.py that is not stored in the default QGIS-user-folder like ~/.qgis2 or a folder used with the configpath option. The startup.py I want to use should be located in a ...

When using Raster Image Fill in QGIS I have no problem getting the image there but is there any way to make it stay one size within the shapefile rather than changing depending on how far you zoom in ...

I am trying to import a csv layer and run QgsExpression.evaluate() to make some computations on existing columns. However, QGIS 2.18, 3.2, and 3.3 all close when it reaches that point. layer....

I am using Google Satellite (via QuickMapServices) in QGIS to count settlements in a certain area, and I'm looking to compare this settlement data to satellite imagery from a few years back. Is there ...

I've been searching for a way to generate server side static maps using Python (or any other languages, doesn't matter). I can create the maps I want with QGIS (and they look really great) but I don'...

I have a contour map in DXF imported to QGIS. How do I turn on the elevation labels for each contour so they are visible. I thought I had done it by clicking on the layer and selecting properties > ...

In QGIS 2.18 I can view OSM using XY tiles no problem. In 3.2 however, copy/pasting the same string in the URL for a new connection doesn't work. The CRS for both is the same. In 3.2 it doesn't matter ...

I have a set of 50 TIFF rasters from an aerial survey that I would like to use to create a continuous map. Each raster is large- ~100mb. The images are not a true grid, and there is overlap between ...

Say, I have a raster with some annual statistics data. Then Daily avg = Annual / 365 Weekly avg = Annual / 52 Monthly avg = Annual / 12 I know I can do this via Raster calculator in QGIS (v2.18.15)...

I am having a lot of issues with Bonn 3.2.2 QGIS and would like to uninstall this version and install an older version that is more stable. What seems to be a stable version of version 3? What is ...

So basically I have my QGIS project which loads a bunch of layers from PostgreSQL Problem is that sometimes users need to copy like 500 or 1000 features from a few of the bigger tables and in the ...

I'm new here and beginner with python. I'm looking for a solution to my problem for some hours but now you are my last chance... I'm using the python (2.7.5) console in QGIS (2.4.0). Is there a ...

I apologize for posting yet-another-gis-novice's confusion about CRSs, but I have researched the issue and am surprised by what I'm seeing. In simplest form, I open a new project set On-the-fly (OTF)...

In this screenshot of QGIS, you can see that the map is not filling the window. I have tried resizing the window in various ways. Am I missing something obvious, or is this a bug? Versions: ...

Are the out-of-the-box geoprocessing tools in QGIS and ArcMap able to analyze rasters stored in a geopackage? Or do they need to be extracted to e.g. GeoTiff first? I'm thinking, for instance, of ...

I recently installed the 3.2.2 version of QGIS but the interface seems to be weird How can make the map canevas occupy the rest of the window?

I'm trying to generate a Steiner tree in QGIS 2.18.2 using a simple set of points, and a simple line vector. See the screen shot below: I then open up v.net.steiner, set the points and vector ...

I've just updated to the current version (2.18.5 on Windows) of QGIS, in the hope of getting rid of the above error, without success. Some time ago I tried to install the QField Sync plugin, which I ...

Is there any way that I can embed and use QGIS Processing algorithm written in python on Qt Creator using C++. If so how can I share the layer and other instances created in C++ with the embedded ...

I have a shp of lines; all the lines have only two vertices I want all these traits to be "mirrored", or overturned to be clear, around their starting point. The image explains the concept better; in ...

I have a raster map consisting of 22 land cover classes (LCC). Each pixel is 300 x 300 meters in dimension and contain one of the 22 LCC. I need to make 1 km x 1 km cells in the parent grid and count ...

I would like to style polygon layer using geometry generator to create point patterns but using just generated points geometry. Is it possible? How can I achieve that? I know that I can use just use ...

I've been using QGIS with the Semi-Automatic Classification plugin (SCP) at work, and am attempting to install and use it at home. Unfortunately, I am encountering an error which causes QGIS to crash ...

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