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1500 questions
26
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5 answers

Is it appropriate to create vertical scale bars?

I'm working on a map where the main theme is a railway line which runs vertically down the page. I've been wondering how to approach creating a scale bar for this map. To my eye a horizontal scale bar looks wrong in this case - it's not easily…
ndawson
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4 answers

How to remove a QGIS project from the "Recent Projects" list?

I have a project in the QGIS Recent Projects list that doesn't exist anymore, but it keeps being listed (greyed out and without thumbnail image). Is there any way to remove it from the list? Perhaps by manually editing a history file or something…
arjan
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26
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5 answers

Install QGIS 2.14 Essen on Ubuntu 16.04 Xenial

I'm having trouble installing QGIS on Xenial. `debian` release When I try using the debian release (i.e. without ubuntugis dependencies) I get the following errors (please note there is no xenial release so I've used wily when setting up the…
Phil
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26
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5 answers

Using ArcGIS functionality in Python without running ArcMap (e.g. separate editor/environment)?

I'm trying to take the next step in programming ArcGIS with Python and see if its actually possible to run my script/code without having to load ArcMap and paste them into the Python window. I imagine I would do this view some sort of IDE specific…
mindless.panda
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26
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6 answers

Is GPS more accurate on specific hours of the day?

I have heard that the GPS system is more accurate, and less accurate on some specific hours on the day. If this is true, how can I get the information on when GPS is more or less accurate at my location? And how big is the difference? I guess this…
Jonas
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26
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3 answers

Simplifying adjacent polygons using PostGIS?

I encountered a problem simplifying set of polygons that are adjacent. If I simplify each polygon separately with the Douglas–Peucker algorithm (which is used by many open source tools), the resulting polygons are usually not adjacent anymore. This…
stachu
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26
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3 answers

What resampling technique should be used when projecting aerial photos?

I'm doing some time-intensive projecting of aerial photos. What resampling technique is best to use on aerial photos? In ArcMap, my options are NEAREST, BILINEAR, CUBIC, and MAJORITY. Nearest Neighbor and Majority are recommended for categorical…
Tanner
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26
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4 answers

How can I optimize pgrouting for speed?

I am using pgrouting on a postgis database created through osm2pgrouting. It performs very good on a limited dataset (3.5k ways, all shortest path A* searches < 20 ms). However since I have imported a bigger bounding box (122k ways) from europe.osm…
mrg
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26
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3 answers

What units are used by GeoPandas/Shapely area and distance functions?

it looks like a silly question, yet I can't find clear answer on that: what units geopandas/shapely use calculating distance/area between objects?
Philipp_Kats
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26
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3 answers

Major bug in ArcGIS Zonal statistics?

Update: The bug has been fixed in the ArcGIS 10.4 release I am using ArcGIS 10.2.2 to determine zonal statistics for a number of zones. If there is any NoData in the value raster, I want the zone results to be "NoData", precisely as advertised by…
G-wizard
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26
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5 answers

Rendering overlapping lines

I am making a map containing information about public transportation: busses, trams, etc. The map will have a layer containing for example the tram lines. Each line has its own colour, and is represented by a line string geometry. The problem is,…
Liedman
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26
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7 answers

Are any fictional worlds available in some GIS format?

Is there any fictional world (e.g. Middle-earth, Discworld etc.) which could be used in a GIS context? For example, an MBTiles archive and a shapefile or any other format usable with OpenLayers / Polymaps / Leaflet?
Nikolai Prokoschenko
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26
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4 answers

Is there an open source GIS to view and edit CityGML models?

I'm looking for an open source GIS that supports viewing and editing of CityGML models. So far, I've found a list of open source applications that support CityGML, but they all seem to be stand-alone applications, that don't integrate with common…
underdark
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26
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3 answers

Order of polygon vertices in general GIS: clockwise or counterclockwise

Two days ago I asked a question about the internal storing order for the vertices of a polygon in ESRI shapefiles. That question was answered (Are polygons stored clockwise or counterclockwise in a shapefile?) and it was also answered in an old post…
jgpallero
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26
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4 answers

What is the difference between Coverage, Shapefiles and Geodatabases in ArcGIS?

I was wondering about the difference in spatial data storage methodology used by Coverages, Shapefiles and Geodatabases in ArcGIS. Coverage was the initial format, followed by Shape Files and now Geodatabases. So what has improved in these newer…
Abhishek Potnis
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