PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

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create automatically temperature or isotherms map with PostGIS?

Is there any possibility to create automatically temperature or isotherms map through a points table stored in PostGIS? I need to serve this map on a web (Geoserver). The information is updated each ...
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219 views

Which equal-area projection to use for UK?

I have a bunch of UK polygons that are saved in my PostGIS database as WGS84 projection. I would like to calculate the area of these polygons using st_area. According to this answer I can save these ...
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66 views

Confused about ST_DWithin function postgis

First Time here. Anyway, I have a database that I want to use to store user locations. I want to be able to get all the users with in say 15 miles. How do I do this. I'm using PostGIS 2.1. My SQL ...
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30 views

How to Increase the length of column type geometry in postgres(pgAdminIII)

I am just wondering is there any way to increase the default length of column type geometry in postgres. Since we are trying to save large number of vertices polygon in to the geometry column geom in ...
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40 views

Any way to speed up my postgis topology creation?

I need to do topology aware simplification, and I'm investigating PostGIS's new topology extension. However it's taking a very long time to create the topology, and I'd like to know if there's ...
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100 views

Query to Dissolve Nearby Polygons on Hive

I am using the ESRI spatial framework for Hadoop, that extends Hive to use spatial types and operations. My objective is to translate a set of simple queries on PostGIS into Hadoop, in order to ...
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112 views

How to split lines with PostGIS and view the result in QGIS?

I have two tables, one contains lines (test_line) and the other contains the points at the vertices of the lines (test_line_vertex). I want to split the line into individual segments based on the ...
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32 views

Upload SHP to PostgreSQL via QGIS

There was the error when I try to upload the SHP to the PostGRESQL. The feature is the line type. The error was: ERROR: Geometry type (LineString) does not match column type (MultiLineString) Do ...
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55 views

Cannot see line made with PostGIS ST_MakeLine() in QGIS

I am probably missing something obvious while trying to do this basic job. thetable contains gps track points. The following aims join the track points by a line: CREATE VIEW line01 AS ( SELECT ...
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99 views

Store GPS trace with timestamps, then interpolate location by time

I'd like to: Load a 1-second interval GPS trace (not GPX) into PostGIS Then query the table at sub-second accuracy (about 5Hz), and get PostGIS to interpolate the location by time. Is this ...
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74 views

Cartographic-complete Maps in PDF On Request using Open Source?

Currently I have some data in PostGIS. I want to implement the following: users will make a request via web, with parameters like location, scale, layers to be displayed, etc. and I need to provide ...
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51 views

How to get the geometry value from coordinates

I have a table with empty geometry column. I have two columns in the same table which has xcoordinate and ycoordinate values. I want to get the geometry value formed by these two coordinates. The ...
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233 views

Why is the Google Maps circle shape not matching to the distance calculated with PostgreSQL?

I am running a PostgreSQL 9.1 Database with PostGIS 1.5 extension. Several coordinates are stored in there with type GEOMETRY (SRID 4326). I'm building a web-application with Google Maps Javascript ...
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45 views

How do I get the vector and raster metadata from a PostGIS database?

im using php/postgres/postgis in a webapp, im wondering if its possible to get metadata from the db about all shp/geotiff table like (name, projection, type(ship/tiff), date, desc, owner etc ...) i ...
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52 views

PostGIS GML round trip confusion

I've investigated the issue of coordinate order in GML and each time I think I've got it but I find my self confused once again. I think some of my confusion may be to do with PostGIS. Doing a ...
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79 views

Delete duplicate geometry in postgis tables

After - I dont know what happend - all my entry's in my postgis tables are doubled! I tryed that to delete them but it does not delete any/all duplicates: DELETE FROM planet_osm_point WHERE ...
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85 views

Vector to raster, then map algebra

I have a table of polygons representing travel time isochrones on particular days. For each origin point, there are five isochrone geometries (stored in separate rows). For each origin point, I want ...
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2answers
111 views

How can I smooth or resample a DEM to find steep roads?

I am trying to find sections of road with steep gradients. My process is: pull a linestring from Openstreetmap data resample it to create a point every 10 metres look up the height data for each ...
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101 views

Print button greyed out on GeoExplorer

I have recently downloaded and installed the OpenGeo Suite from Boundless, and I am running through a few tutorials. I'm using GeoExplorer to manipulate layers defined in GeoServer (running from my ...
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2answers
115 views

How to export thousands of features from PostGIS to a single GeoJSON file?

I know how to export one feature from a PostGIS database using ogr2ogr: $ogr2ogr -f GeoJSON out.json "PG:host=localhost dbname=xxx user=xxx password=xxx" -sql 'select id, county, wkb_geometry from ...
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62 views

how to query contour postgres db for elevation at a point using postgis

Is there a way to interpolate between these contour lines for a given point using postgis? Thanks. I've come up with the following query to gather the potential contour lines of interest: ...
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72 views

How can I measure linestring on postgis?

I have a linestring and I want to measure this line. I try it on google maps. the result is that 0,65 km ...
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62 views

postgresql rule to trigger

I have two spatial tables and I am mirroring the data between the two table with a postgres rule: CREATE OR REPLACE RULE create_centroid AS ON INSERT TO csg.client_area_request DO INSERT INTO ...
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281 views

Downloading the distribute_setup.py

I need to download distribute_setup.py from the following website and the website seems to be broken, has anyone got an idea where else I can download this from? ...
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1answer
58 views

Get closest (source or target) of an edge from a point in postgres

I have a Postgres custom function that uses pgr_dijkstra to generate a route working. It works be passing the lat/lon of the start and destination points. I then find the closest segment vertice to ...
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94 views

artifacts in SRTM contour layers processed with GDAL tools and rendered with mapnik

Here is my workflow for importing individual SRTM tiles into postgis using the GDAL utils and rendering a png using mapnik: gdal_fillnodata.py -srcnodata -32768 gdal_contour -i 10 -a ele -snodata ...
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76 views

Split OSM highways at vertice

I am looking for a tool or query to split the OSM highways into multiple segments. Each segment should only consist of two nodes (start and end). I should do the same as described in this GIS ...
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2answers
89 views

finding the outermost border of a set of geomertries (circles)

I have a (large) set of geometries (circles) that overlap.! I would like to find the nearest location outside of this group from my current location. In this example my location is the black dot. In ...
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1answer
69 views

Creating new lines from existing lines based on points lying along the lines

I am pretty new to PostGIS and I have a problem I just can't figure how to start. I have a table of lines (id, name, the_geom) and a table of points (id, name, the_geom). Each point is located on a ...
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2answers
155 views

QGIS project with PostGIS layers freezes irregularly for minutes

I'm using about 30 more or less complex PostGIS layer in my QGIS project. Some of them are PlanetOSM layer generated with osm2pgsql. The Project loads fast (ca 5 sec). The canvas update by moving or ...
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45 views

Import .gfs file into PostGIS?

Is it possible to import a .gfs file into PostGIS? I can open the .gfs file in QGis, so I assume it is a geographic file of some kind: but I'm not sure how to get it into PostGIS. I have Googled but ...
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44 views

ogr2ogr: Can I add a field when I import to PostGIS?

I have a bunch of GeoJSON files that I want to import to a PostGIS database. I can import individual files perfectly as follows: ogr2ogr -f PostgreSQL PG:"host=x user=x dbname=x password=x" ...
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211 views

PostGIS doesn't use index for spatial query

I can't get PostGIS 2.1 running on PostgreSQL 9.3.5 to use a spatial index even for the simplest queries. The whole dataset is 8 million points (population count grid from here ...
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41 views

Generate random points in geometry near heatspots

I have an algorithm, that generates random points with in a given polygon (Generate random points in polygon. Algorithm question). The Polygons the points are generated in are communities or districts ...
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1answer
111 views

How to refresh features on a OL3 map automatically?

I am using OL3 and GeoServer and PostGIS as database. My database is connected to GeoServer and OL3 conected to GeoServer and reads the points in database as vector layer and shows on the map. My ...
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89 views

osm2pgsql cannot connect to postgis database, running on a Bitnami project installer

Based on this guide I am trying to import an .osm.pbf file into my PostGIS database, which is running on my Postgres Bitnami installation here: [bitnami@ip-xxx]/usr/share/proj$ which postgres ...
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164 views

Intersection postgis TopologyException

I'm trying to make a quite simple analysis in Postgis, but I'm finding some problems. I want to in the first place create buffers for then, intersects themselves but one, this will be differenced. ...
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166 views

What should be my learning progress regarding GIS open source [closed]

I was wondering for a while now, what should be the hierarchy of my GIS knowledge or better to say, learning curve in domain of open source GIS. Should I start with Geoserver and PostGIS then ...
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73 views

How to split linestrings where start/end points don't touch nearby lines

I am trying to figure out some basic routing with PostgreSQL/pgRouting and I'm struggling a bit. Our network of linestrings are not topologically correct, tracks that should be connected don't touch, ...
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23 views

postgis resampling two rasters to a common grid system?

I am testing the PostGIS map algebra (ST_MapAlgebra) on two different raster tables. Each table contains a single image/row. They have the same SRID but different, overlapping extents and different ...
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27 views

PostGis: find distance if closer than X. For huge sets [duplicate]

I have two tables (that can have different geometry: point, line, polygons, ecc...) and I have to find distances: for all features in table A, for all features in table B, if feature is closer ...
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1answer
43 views

Is product purchaser in distribution area?

I am going to be using PostGIS 2 to create a lookup service. Given a point (lat/lon), I need to either find if a product can be distributed there, or b) a list of products or distributors. I am ...
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89 views

Solving “Traveling Purchaser Problem”

Till now, I was using PostGIS-pgrouting pgr_tsp function to solve Travelling Salesman Problems. This function can give us the best possible route depending upon the cost parameter when the starting, ...
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56 views

strange result of spatial functions postgis

I have a problem with different result of spatial functions for same geometry. For some reason result I get when I use geometry from database is different then result when I load same geometry from ...
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1answer
58 views

Layer from PostGIS with array of integers fields?

I have GeoServer 2.6 and I published a vector layer (point) which some of the field attributes are integer's array. GeoServer doesn't recognize those fields in wfs call or even in the Feature Type ...
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11 views

How to get linestringe from kml into shp or postgis [duplicate]

Im looking into extracting linestrings from a kml file into a shp file or postgis db. Each linestring would be a feature/row. How would I go about it usinge ogr2ogr or python? I'd like to get ...
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20 views

ogr2ogr - gpx to PostGIS has wrong timezone adjustment

A gpx track point: <trkpt lat="52.321775959804654" lon="-72.647269548848271"> <time>2014-10-01T16:07:19Z</time> </trkpt> is imported with ogrogr in my PostGIS ...
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35 views

Create polygon with predefined size

I need to create a polygon (square) with a predefined size to place it anywhere in a map. The size is given in centimeter (size in cm * scale = size in real). Is that possible with postgis/qgis?
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29 views

OpenGEO templates and postGIS

I am trying to display my shapefiles.shp with ol3edit template. On OpenGEO Suite I have successfully created an ol3edit application.I'm in possession of the ol3editApplication.war but the ...
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41 views

Splitting multiline into several same-length multilines

Is there a method to convert a multiline geometry into several multiline geometries having the same length? For example break this: MULTILINESTRING((1 1, 3 1, 3 1.5, 2.5 1.5)) Into [approximately] ...