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1500 questions
19
votes
2 answers
Listing all polygon vertices coordinates using GeoPandas
I'm trying to list all polygon vertices coordinates of a rectangle with four corners and a hole with four corners. I drew the vertices in this order:
import geopandas as gpd
#import matplotlib.pyplot as plt
import numpy as np
df =…
BERA
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19
votes
4 answers
What is the difference between geocoding and georeferencing?
After some googling around both seem to be interchangable words, where we speak of tying the spatial info of a real place and storing in database.
But still I am not satisfied, there should be some major differences. Also are there any tools in…
azzaxp
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19
votes
1 answer
Writing a python processing script with QGIS 3.0
Following the update to QGIS 3.0, it has become very difficult to find any information concerning the writing of processing scripts in QGIS 3.0.
@Underdark (see here ) has provided a basis for the skeleton. This code also seems to have been added in…
Kantan
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19
votes
2 answers
Unable to snap vertices and segment in QGIS 3.0
I'm unable to snap 2 polygons in QGIS 3.0. I tried snapping 2 polygons from the same layer and also 2 polygons from different layers.
I ensured that snapping is enabled in the Settings>>Options>>Digitizing tab, and increased the snapping distance.…
adele.k
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19
votes
2 answers
Finding tunnel center line?
I have some map files consisting of 'polylines' (each line is just a list of vertices) representing tunnels, and I want to try and find the tunnel 'center line' (shown, roughly, in red below).
I've had some success in the past using Delaunay…
sje397
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19
votes
1 answer
Why are geolocations on Twitter "rounded"?
I'm plotting some geolocations (lon, lat) of tweets collected using the Stream API with a 7mi. radius. The picture below shows two maps of the same data, but using different alpha/transparency for each observation.
Looking at the map on the left, I…
Dambo
- 289
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- 10
19
votes
7 answers
Seeking neighborhood boundaries globally?
Besides Zillow's creative-commons licensed neighborhood boundaries shapefiles, what sources of neighborhood boundaries are there? Not just in the US, but all over the world.
Free/open source is ideal, but paid sources could be interesting too.
Avishai
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19
votes
4 answers
The best language to program with GDAL
I'm going to start to create programs to handle geographical data from a PostGIS server, and going to use GDAL.
According to your experience, with the best language to program with it? I can program in Perl and Python, but would like to know the…
SonOfabox
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19
votes
3 answers
How to combine sfc objects from R package sf
Using the R package sf, how does one combine sfc objects? For example, given the following code, how would one create a single sfc object sfc12 that includes the geometries from both sfc1 and sfc2? (length(sfc12) should be 2.)
library(sf)
pt1 =…
andycraig
- 338
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- 7
19
votes
1 answer
Robust alternatives to Moran's I
Moran’s I, a measure of spatial autocorrelation, is not a particularly robust statistic (it can be sensitive to skewed distributions of the spatial data attributes).
What are some more robust techniques for measuring spatial autocorrelation? I’m…
MannyG
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19
votes
5 answers
Converting polygon into single or all points in QGIS
I want to convert polygons into points using QGIS.
I know how it's done in ArcGIS Desktop.
How can I implement it using QGIS?
Lukas
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19
votes
5 answers
Is GIS industry always ruled by two options only, namely Esri products and OSGeo projects?
I always wonder, why in GIS industry there are merely two major options available. Although there are many other proprietary software products for GIS, their market share is well below ESRI products (here, here and here although quite back dated).…
thelastray
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19
votes
5 answers
How to export Polygons to CSV with coordinates?
I am very new to QGIS, so please bear with me.
I have a ".shp" file, which is contains a set of boundaries for suburbs of Australia. I opened it to QGIS and I would like to export it into a CSV file so that the final file would be like…
ericbae
- 293
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19
votes
2 answers
Creating leader lines for moved labels
With a lot of help from gis.stackexchange.com I've created leader lines for point symbols. The lines are based on a geometry generator symbology:
Shortening line geometry using expression dialog in QGIS?
Now, I want to implement leader lines for…
eclipsed_by_the_moon
- 1,855
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- 44
19
votes
2 answers
Converting cluster of Points to Polygons using QGIS
I have an input point layer that is grouped into clusters, so I want to have each cluster of points converted into polygon.
This question How to convert a set of points to a polygon based on a specific field in QGIS (this question was removed) seems…
Umar Yusuf
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