Questions tagged [postgis]
PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.
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When is pgSphere bundled with PostGIS?
I am currently dealing with an analysis of replacing pgSphere with PostGIS and I have a question about PostGIS:
We can read on https://postgis.net/documentation/getting_started/install_windows/...
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Similarity index for pairs of features with the highest overlap? [closed]
A few weeks ago, I posted an initial message:
Percentage of area overlaped / covered by features of another layer
But after further thought, I'm creating a new one to provide additional inputs/...
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Creating centreline or medial axis of complex polygon - pruning outputs or an alternative approach? [duplicate]
I am attempting a workflow to map steep banks of eroding soil on peat bogs. I have a detailed DSM of the area of interest, and a detailed orthomosaic, both at capture resolution from a drone with ...
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How does ST_AsRaster with a given geometry and pixel size choose the number of pixels?
(PostgreSQL 18.0, PostGIS 3.6.0)
I don’t understand how ST_AsRaster decides the dimensions of the raster. I was expecting that the SQL below would give me a raster with its top left corner at (-1, 3) ...
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PostGIS GUI not showing up
I Installed last version 18 of PostgreSQL, addedd PostGIS extension using stack builder. But the PostGIS bundle does not work, it cannot find the .exe file in the folder. Looking for a tutorial for ...
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error of ST_Polygon(raster) function in PostGIS 3.4.3 [closed]
I am using PostgreSQL 17 and this version of PostGIS:
POSTGIS="3.4.3 e365945" [EXTENSION] PGSQL="170" GEOS="3.9.0-CAPI-1.16.2" PROJ="7.2.1 NETWORK_ENABLED=OFF ...
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Percentage of area overlaped / covered by features of another layer [closed]
I'm working with PostGIS.
I have two vector layers :
A first polygonal layer resulting from vectorization work using photointerpretation of the aerial imagery (in blue in the attached screenshot ...
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Relationship between tables in a GDB
I’d like some clarification. I’m new to the GIS world. I imported a GDB provided by a public agency into QGIS. My question may be very obvious, but I just want to avoid future issues.
Should the ...
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Vector layer cannot be exported to PostGIS
I am trying to export a vector file in a PostGIS database using QGIS "Export to PostgreSQL" processing tool. I have successfully exported other vector specially small sized data. However, I ...
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Connect centroids of adjacent triangles from ST_TriangulatePolygon when tiny gaps break adjacency
I’m building lines between the centroids of adjacent triangles produced by ST_TriangulatePolygon. CRS is EPSG:3857.
The goal is to connect triangle centroids only when the triangles share an edge (not ...
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Dissolve keeping all attributes values (concatenation/aggregation) using PostGIS
I work with QGIS and PostGIS. I would like to perform a "dissolve":
QGIS dissolve
in keeping all attributes values? For instance: a kind of aggregation/concatenation within new "output ...
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Writing to GeoServer using PostGIS in FME
I want to write a dataset with the PostGIS writer to GeoServer, but the result contains errors.
Process: A reader of municipal boundaries, and a reader with fire hydrants, the fire hydrants gets ...
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Getting NULL values with string_to_array function in QGIS
I work with QGIS and PostGIS. With PostGIS, I ran an SQL script that contains a section dedicated to aggregation geoprocessing: from multiple source data, each containing a unique ID, this allows to ...
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Merge adjacent polygons based on attribute condition using QGIS [closed]
I work with QGIS.
I have a polygon layer of 4,000 objects. A 'hierarchy' field provides information on the confidence level: 1, 2A, 2B, 3A, 3B.
Of these 4,000 polygons, 3,000 are actually small ...
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Does PostgreSQL/PostGIS on AWS RDS use OSTN15 transformation files for 27700?
I’m running PostGIS 3.4.3 on AWS RDS (PostgreSQL 16) with PROJ 9.5.0 (postgis_full_version() output).
We used to handle UK coordinate transformations outside of PostgreSQL (with ogr2ogr and PROJ 6.x) ...
