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Questions tagged [gis]

A Geographic Information System (GIS) captures, stores, analyzes, manages, and presents data that are linked to location(s). The GIS Stack Exchange should be considered for questions with this tag.

According to Wikipedia:

A geographic information system (GIS), geographical information system, or geospatial information system is any system that captures, stores, analyzes, manages, and presents data that are linked to location(s). In the simplest terms, GIS is the merging of cartography, statistical analysis, and database technology.

There is a Stack Exchange site devoted to Geographic Information Systems.

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ImportError: Spatial indexes require either `rtree` or `pygeos` in geopanda but rtree is installed

I am trying to clip spatial data in python but when I run my code... europe = gpd.clip(worldmap, europe_bound_gdf) ... I get the error: (ImportError: Spatial indexes require either rtreeorpygeos`.) When I try to install rtree using: pip3 install…
JoshuaAJones
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Calculation of accumulation area

I'm looking for a GIS/Geometric algorithm: I have 1000 points randomly distributed in a large area(such as a city), How can I find out all the small areas which have more than 15 points? Like this picture below: Each point has its own latitude and…
Leo
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Multi-Layer .gdb files in Python?

I'm trying to read in some .gdb files(folders?) from here: . I use GeoPandas and do the following: # file from local path mallard = gpd.read_file('./bird-species/E00039600_mallard.gdb/') # geopandas included map, filtered to just this…
pngbrianb
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Optimising Shiny + Leaflet performance for detailed maps with many 'layers'

I want to make a Shiny app where the colouring of a choropleth is based on a numeric value of one of many possible quantitative variables that a user can select from. In simple cases, this is straightforward, but I'm unsure of the best practices…
dcl
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How can I get the installed GDAL/OGR version from python?

How can I get the installed GDAL/OGR version from python? I aware of the gdal-config program and are currently using the following: In [3]: import commands In [4]: commands.getoutput('gdal-config --version') Out[4]: '1.7.2' However, I suspect…
fmark
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Google Maps and SQL Server LINESTRING length inconsistent

Google Maps and MSSQL seem to disagree on how to calculate the distance/length of a polyline/linestring using SRID 4326. MSSQL: SELECT geography::STGeomFromText('LINESTRING(-98.78 39.63,2.98 27.52)', 4326).STLength() Result: 9030715.95721209 Then…
ParoX
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Buffer (geo)spatial points in R with gbuffer

I'm trying to buffer the points in my dataset with a radius of 100km. I'm using the function gBuffer from the package rgeos. Here's what I have so far: head( sampledf ) # postalcode lat lon city province #1 A0A0A0 47.05564…
vathymut
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Installing shapefile / shapelib not found via conda or pip

I am trying to read shapefiles to view suburbs in a city following this tutorial using windows 8, Anaconda and iPython. I tried "conda install shapefile" and "pip install shapefile" in command prompt, both returning "Error: No packages found…
James Salamon
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Getting bounding-box of city

I want to know how far a specific geographic coordinate is from a list of cities ('far' meaning the euclidean distance between the coordinate and the city, not taking roads into account). For this I need to find a bounding-box for each of the cities…
zmbq
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How to read / write geography data using C#, Entity Framework and SQL Server 2008?

I have a form from which the user will be able to enter the latitude and longitude of a certain point on the map. The data will be input as string values. I did some research and found out from various sources that the Entity Framework doesn't…
Filip Filipovic
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How to convert polygon data into line segments using PostGIS

I have a polygon data table in PostgreSQL/PostGIS. Now I need to convert this Polygon data into its corresponding line segments. Can anybody tell me how to convert it using PostGIS queries. Thanks in Advance
gouse shaik
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Color states with Python's matplotlib/basemap

I want to generate a map of the United States and color each state in using a different shade. Is there a way to do this using Python's basemap?
heyitsbmo
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Set the right crs on sf object to plot coordinate points

I'm trying to define the right CRS for my sf object. I want to plot points atop the following layer (country: the Netherlands): Simple feature collection with 380 features and 3 fields geometry type: MULTIPOLYGON dimension: XY bbox: …
Tdebeus
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GeoDjango: How to create a circle based on point and radius

I have the following (simplified) Model: class Zone(gismodels.Model): name = gismodels.CharField() poly = gismodels.PolygonField() I want to create and save a polygon that represents a circle, based upon a given point and radius. The only…
MattRowbum
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Is there a GIS "Hello World" Equivalent?

Is there the equivalent of the "Hello World" program for GIS applications? I am looking to become more familiar with the development of GIS applications. What are the popular (and free/low cost) tutorials and/or sample applications that would help…
user53474
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