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1500 questions
16
votes
3 answers
Performing route analysis in R based on OSM transport network?
I'm analysing the likely paths taken by commuters on their way to work, based on Census flow data, job density distributions and the transport network.
At the moment I'm using pgRouting and the pgRouting add-on for QGIS (described here) for my…
RobinLovelace
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16
votes
4 answers
How to handle TIME in GIS?
Is there any way or any idea on how to handle Time attribute in GIS? For example, which are the ways to specify that an object is at a place at a given time interval and them it is in another place in another time interval, let's say, like a…
Pablo
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16
votes
2 answers
PostgreSQL/PostGIS spatial index - no speed up
I have a spatial table in a PostgreSQL/PostGIS database. Every row in it represents a Polygon. It is of following form:
+----+--------+
|gid | way |
+----+--------+
|241 | 01030..|
The geometric column is "way" which contains the geometry for a…
MichiMichbeck
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16
votes
4 answers
Removing duplicate point features using QGIS
I have created many .gpx data with my Garmin device, but due to the amount of data, I have imported the mapping data from my device several times (also because I didn't want it to be lost).
As a result, I have now many double or even 6 times the…
Lukas
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16
votes
6 answers
Looking for free program, similar to 3D Analyst, to visualize tree stands in 3D
I want to make a 3D stand visualization of trees in a specific area. I need something similar in functionality to ArcGIS 3D Analyst, but I don't have a license for that plugin anymore.
The only alternative I have found is the Stand Visualization…
Curlew
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16
votes
4 answers
OpenLayers: how to style WFS layer with SLD file?
I'm experimenting with a simple web mapping service build on PostGIS/GeoServer/OpenLayers stack on Win 2008 Server.
I overlay vector layer from PostGIS using:
var Index1v = new OpenLayers.Layer.Vector("Index1 v", {
strategies: [new…
radek
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16
votes
3 answers
Exporting only certain columns to CSV file in ArcGIS for Desktop?
I've written a python script using arcpy which outputs a polygon feature class into a File Geodatabase. I have added a function to export the attributes to a separate CSV file. I am using the code which I have found in this post which works…
Fezter
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16
votes
3 answers
How to speed-up Dynamic Map services?
I am working on a ESRI Flex based application that will display data from a Dynamic Map Service. It need to be Dynamic, since the end user should have the option to turn on & off layers. This is possible only with Dynamic Map services & not Tiled…
Devdatta Tengshe
- 41,311
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16
votes
4 answers
Are there tools to directly import QGIS projects into Tilemill?
Now that there is a tool to convert an MXD to Tilemill, one must then wonder if the ability to open QGIS documents in Tilemill will ever exist.
DPSSpatial_BoycottingGISSE
- 18,790
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16
votes
4 answers
Creating perpendicular lines on line using QGIS
In QGIS I want to create perpendicular Lines on another Line (River). The Lines should be created on points on the Line and should have a length of 40 Meters. I want to create the red lines in the picture below (for the complete River).
KartenLappen
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16
votes
2 answers
Difference between QgsPoint, QgsPointXY and QgsGeometry.fromPointXY() in PyQGIS
I am using PyQGIS. What is the difference between:
QgsGeometry.fromPointXY(QgsPointXY(x, y))
QgsPointXY(x, y)
QgsPoint(x, y)
When I print these three options, I get:
print(QgsGeometry.fromPointXY(QgsPointXY(x1, y1)))
Sara Isabel Aleixo Perestrelo
- 333
- 3
- 6
16
votes
6 answers
Quickly review all the features one by one in QGIS
I have about 400 features in a point dataset. I would like to (quickly) visually check their locations one by one on the map. For now, I open the attribute table alongside the map. I select the first row and use the Zoom to selected feature button.…
Marc
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16
votes
2 answers
How to install or build GDAL 3+ on Debian buster?
I'd like to install GDAL 3+ on Debian stable. Is this not possible? I've read GDAL docs and looked at Debian package tracker.
With the default source.list for Debian buster (current stable as of October 2020), only GDAL 2.4 is available. Any…
Keto
- 263
- 2
- 6
16
votes
5 answers
Applying version control to ArcGIS ModelBuilder models?
Version control is an indispensable tool for software development, allowing one to reliably and cleanly step back in time to the last time X did it's job exactly right, or to see what changed between then and now -- typically used when trying to…
matt wilkie
- 28,176
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16
votes
3 answers
Performing GIS benchmarks?
I was searching the web for benchmarks (but couldn't find any) that would indicate hardware performance (probably cpu in particular) in different GIS software in time consuming tasks (like hillshade generation, raster reproject, topology buildup),…
U2ros
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