Questions tagged [python]
Python is an open source interpreted programming language used in many GIS programs.
2,567
questions with no upvoted or accepted answers
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MapScript with Python 3
I am trying to build raster summarizing features into a GeoDjango webmap,
and would like to use the django-raster and django-wms packages to do so. I believe that I have them set up correctly, but am ...
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11
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0
answers
2k
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Making polygon for every point in set using Voronoi diagram
I'm trying to make polygons from points, where each point will be represented by one polygon. I tried using Voronois, but the results are incomplete. While I more or less understand where this ...
- 539
8
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0
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268
views
OGR failing to unpack polygons and respective holes from shapefile
I'm trying to unpack shapefiles in Python (v3.7.4) using the GDAL-OGR library (v2.3.3). Each shapefile has only one feature containing multiple polygons with holes. They cannot be produced differently....
8
votes
1
answer
688
views
Finding the closest line to polygon using Python Rtree
I have a series of fields and roads. I am trying to find the nearest road to each field. I want to add field to each of my polygons with the index/name etc. of the closest road.
Would this be the ...
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8
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922
views
Nearest neighbour joins for two geodataframes using KDtree from scipy/sklearn
I have a number of large geodataframes and I want to automate the implementation of a Nearest Neighbour function using a KDtree for more efficient processing. The process I want to achieve here is to ...
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8
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3k
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Get rid of jumping GPS data with pykalman
I have gps data that I get from a smartphone application. Whenever the smartphone is stationary, the gps points are jumping. I understand that the signal is inaccurate due to the reception in a city ...
- 181
8
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answers
2k
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GDAL RasterIO performance in C++ vs ReadAsArray in python/numpy
I'm currently writing optimisations for a raster viewer program which uses gdal as it's base. It's currently written purely in python, and has some major speed issues which cause problems when we are ...
- 213
8
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612
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Setting up PyCharm CE 4 to work with PyQGIS library in Mac OS
I am trying to set up PyCharm to work with PyQGIS library. I am using PyCharm CE v4 and QGIS version 2.8 I have tried to implement the instructions of several posts like:
http://osgeo-org.1560.x6....
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7
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211
views
QGIS contextual menu overriding
I would like to override the default contextual menu in QGIS 3 in the ToC.
I've created a class that inherit from QgsLayerTreeViewMenuProvider.
from qgis.gui import QgsLayerTreeViewMenuProvider
from ...
- 463
7
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answers
427
views
Georeference and warp a drone image based on sensor orientation and location
I have been flying some drone surveys over the ocean and need to properly project and georeference my images. I have all the information I think I need: lat, lon, altitude, yaw, pitch, and roll along ...
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344
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Save GeoPandas spatial index to disk
I'd like to save the R-tree spatial index generated by GeoPandas to disk.
GeoPandas automatically generates an index for each shape (points in this case) in the dataframe.
I'm attempting to create a ...
- 399
7
votes
1
answer
219
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QGIS 3.6 and QGIS 3.10 report different geometry types for the same shapefile
I used QGIS 3.6.3 to create a polyline shapefile, and the program reported the polyline as LineStringZM. When I opened the same shape file in QGIS 3.10.3-2, the polyline was reported as ...
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507
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How to create LineString geometry in QGIS3?
The default geometry type for a newly created line seems to be MultiLineString. It can be changed to LineString using the Multipart to Singleparts tool while saving in memory. However, once it is ...
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7
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Overlay Union Geopandas improve performance
How to speed up the "union" of two shapefiles using geopandas?
I have two large shapefiles:
geodataframe_left.shape = (3610, 12) (500 MB) (link)
geodataframe_right.shape = (16396, 3) (200 MB) (link)...
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7
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266
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QGIS plugin external libraries in plugin’s directory
I’m developing my first QGIS plugin and I have to use two external libraries not included in the default OSGeoW64 installation: Couchdb and Pandas.
I would like to include those libraries in my ...
7
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334
views
PyQGIS composed Atlas generation
I have some layers :
layer 1
layer 2
layer 3
and I have create styles for any labels layer using base rule styles and labels and I have create a template .qpt and I use atlas correct.
In my ...
- 1,023
7
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273
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Different results from GDAL raster attribute table command on mac and windows
I am trying to get the raster attribute table of the following file:
Shift_cult_past_current_prediction_20160107_gr1DD.tif available here: https://www.dropbox.com/s/fmomfpro3j6dmz8/...
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6
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118
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Creating a seamless vector dataset from raster with gdal, R or Python
I'm trying to create a seamless vector dataset from an integer raster. "Seamless" as in: not gaps between features and no overlapping features.
The tools gdal_polygonize, pkpolygonize, terra:...
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6
votes
2
answers
353
views
Shortest path touching all points
I am looking for a solution to derive the shortest route that touches all the points using Python. Please note that
This is not a Travelling salesman problem (TSP), in which the route should end ...
- 315
6
votes
1
answer
130
views
GIF freezes when QGIS plugin runs
I have a QGIS plugin and would like to put loading GIF (spinner) somewhere in the Dialog Window. The problem is when I run the spinner with the following code and call next function, the spinner ...
6
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0
answers
155
views
How to transform ERA5 vertical datum to WGS84
I am trying to plot a netcdf file from ECMWF ERA5 in a folium map but I am having troubles with the projections in the file.
ECMWF documentation states:
ECMWF data is referenced in the horizontal with ...
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6
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0
answers
936
views
Convert the geometry column of a GeoDataFrame with mixed geometry types to a unique multi-type
I have a GeoDataFrame where I have a mix of geometry types in its geometry column, some are multi-geometry types, some are single geometry types, some are empty geometry types, and others are None (...
- 6,698
6
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342
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Unable to install QGIS Plugins on Windows
I've installed QGIS 3.16 Hannover on my laptop about three days ago (Windows 10 Home 1909) and am unable to install any plugins, nor get access to any of the core plugins save four.
When going to ...
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6
votes
2
answers
820
views
Adding support to Esri's FileGDB driver when fiona/gdal/osgeo were installed through Anaconda
Is there a way to tweak the fiona/gdal/osgeo packages installed through Anaconda so that they can be used to read/write GDB files using the ESRI FileGDB driver? The main thing I'm actually trying to ...
- 1,737
6
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290
views
Open multiple QGIS projects via PyQGIS simultaneously in different threads
I'm writing a standalone PyQGIS application. When the method qgis() is called in a new thread, it's supposed to open a QGIS project (with one layer in it) and close it again:
from concurrent.futures....
- 151
6
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0
answers
615
views
QGIS 3: Set custom project variables with input dialog
I am using QGIS 3.10.0 and Windows 10. I have a project where I want the user to define custom project variables. I want to make this user friendly, I don't want the user to need to open the project ...
- 123
6
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0
answers
64
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Randomized organic warp of adjacent polygons that preserves topology and fixed nodes
I'm looking for algoritms to modify a set of polygons to make them appear more organic. They still need to maintain their topology and furthermore some of the nodes might be fixed. Please see the ...
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6
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2k
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Multiprocessing with geopandas
I am learning how to implement the multiprocessing with spatial data using the module multiprocessing.
I am trying to implement a spatial intersection between a polygon file and a grid file.
I am ...
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6
votes
1
answer
747
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Competing versions of GDAL
This is confusing, and a question I've harvested from a duplicate, so let me start with my setup.
OS: Windows 7 x64
GIS Client 1: ArcGIS Desktop 10.5
GIS Client 2: ArcGIS Pro 1.4
GIS Client 3: ...
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6
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answers
870
views
Import Pandas or any Python module into QGIS internal Python
(Also asked in stack overflow -
https://stackoverflow.com/questions/43244062/import-pandas-or-any-python-module-into-qgis-internal-python )
I am developing a plugin for the current LTR version of ...
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6
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answers
4k
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What is the fastest version of gdal2tiles?
I have multi-CPU linux server, so I wonder what is the fastest parallel version of gdal2tiles.py ?
My Ubuntu version:
lsb_release -a
Description: Ubuntu 12.04.5 LTS
How I install the package:
...
- 591
6
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0
answers
731
views
netCDF has wrong spatial extent in metadata
I have a netCDF file with spatial data ranging from x:528500 573500 y:350500 399500 on EPSG: 31287. If I open and explore the file with Panoply and show the data on a map all works like it should.
...
- 287
6
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189
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Gdal Python problem: black strips in image translation
I have a 500 x 500 m resolution world map of clumping index data (He et al., 2012) and I am trying to do two things at the same time: 1) to isolate the variables per plant functional type following ...
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6
votes
0
answers
292
views
How to handle large tables in QGIS using Python?
I'm currently writing a plugin that calculates values based on a QgsVectorLayer's attributes. To display and print the values I'm using a QgsComposerTextTableV2. I have several problems with my ...
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6
votes
2
answers
13k
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WindowsError: [Error 32] The process cannot access the file because it is being used by another process
I am reading images (through Python) and do something. These images are placed in a temporary file, through:
tf = tempfile.mkdtemp(filename)
I use gdal to read the images (short part of code):
...
...
- 1,409
6
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0
answers
918
views
Print Composer Template produces empty map?
I have a print composer template which I'm trying to populate with different subset queries from a CSV-derived vector layer using the Python API. However, all the output PDFs contain everything except ...
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6
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0
answers
2k
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Buffering a Raster with GDAL and Numpy
I am using GDAL to convert a raster dataset into a numpy.array and then using numpy to buffer the data in the raster. For example, I need to know all the regions within 100ft of a school point ...
- 4,109
5
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107
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TMS tilenames for Elliptical Mercator projection - EPSG:3395
My goal is to derive TMS tile names from given lat/lon and vice versa for Elliptical Mercator projection (EPSG:3395) using Python.
OSM wiki explains the logic for Spherical Mercator (EPSG:3857), but ...
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5
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508
views
Controlling the visibility of a FeatureGroup in Folium with an HTML checkbox
I'm working on a project in Django where I want to show layers on a map by checking or unchecking boxes which I created using bootstrap. I am aware it is possible to use LayerControl to get these ...
5
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0
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99
views
Where does QGIS download plugin .zip files prior to install?
I have a QGIS Python plugin we use internally. I've released a new version - edited the "metadata.txt" file, zipped it, replaced the .zip package on our web host, updated our plugins.xml ...
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5
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1
answer
390
views
Finding distance from points to the boundary of the nearest polygon in Python
I asked this question on stackoverflow.com but it seems that doing so here is a better option.
Context: I want to compute the distance from points to the closest boundary of the closest polygon to ...
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463
views
Using PyQGIS functions outside QGIS
I want to use PyQGIS function crs.isValid() in normal Python file outside of QGIS like this:
wkt = 'GEOGCS["WGS84", DATUM["WGS84", SPHEROID["WGS84", 6378137.0, 298....
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1
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105
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How to choose limited number of points to represent a point grid
I need to choose a few points to represent the grid below, e.g: 8 points in the grid below. This point need to be geographic distributed
This points needs to be geographic distributed. Lets see a bad ...
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201
views
Finding union of many geodataframes using GeoPandas
I have a series of many GeoPandas Polygon objects, each with an associated exposure time. My goal is to find the union of all the Polygons in order to create an exposure time map.
For each Polygon in ...
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5
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218
views
Programmatically Enable/disable input parameters in a QGIS Processing plugin
Is there a way to enable/disable a parameter by a checkbox in the processing interface? In my screenshot below, I would like to disable the Output Wall Aspect Raster when the Calculate wall aspect ...
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5
votes
1
answer
236
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Optimizing pixel extraction from GeoTiff using Python
I am creating IDF Curves for work using python and 30-minute rainfall rate rasters. There are 24 rasters per day and about two decades worth of data. I basically input lat/lon coordinates and my ...
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107
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QGIS processing tools - saving/exporting graph
I just tried QGIS processing tools for the first time.
When using shortest path search for the first time, the algorithm is building a path graph (of course). However, the graph is never re-used. ...
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5
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96
views
Python osgeo/OGR not returning all features in PBF
I have a PBF file that is a limited export of the Nepal area. I'm trying to pull out all the adminstrative boundaries.
If I use osmconvert to turn my PBF file into a OSM file, sure enough I see the ...
5
votes
1
answer
898
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Using rasterio to show RGB image with nodata
This question is same as https://stackoverflow.com/questions/59132459/use-rasterio-show-rgb-image-with-nodata
I have a multiband image with nodata value (which is Landsat and been set nodata to 0). ...
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5
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293
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Is there a limit to the number of GCPs that can be used?
I am trying to georeference an image using many (>1,000,000) GCPs (derived by matching two images using triangulation). However, after many attempts doing this in different ways I think I found that ...
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