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

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question about Pgrouting dijkstra algorithm [on hold]

I own two tables one with streets and one points, i use the table with the roads to calculate routes with dijkstra algorithm. But I want when someone add one point in the table Point and this point is ...
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23 views

How to get Geography data to GeoJSON in PostgreSQL?

I am using PostgreSQL database and there is a field in a table(area), i.e., public.geography(Points,4326). It contains below type of records "0101000020E6100000BA83D89942334540780B24287ED051C0" I ...
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1answer
21 views

How to find out postgis.backend?

How can I find out which postgis.backend (geos or sfcgal) I have?
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39 views

Does ST_Intersection work in 3D?

I am using "ST_Intersection" between two 3D lines which I believe do not intersect, but the result gives me their intersection. SELECT ST_ASText(ST_Intersection( ST_GeomFromText('LINESTRING( ...
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23 views

ERROR: attempt to redefine parameter “postgis.backend”

I just install "SFCGAL". When I use "ST_3DIntersection", It get below error: ERROR: attempt to redefine parameter "postgis.backend" SQL state: XX000 How can I fix? I already saw ...
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35 views

POSTGIS get the max length of the polygon and the average width

I have in postgis a polygon type table. I need to calculate automatically the maximum length of the polygon: And the second one is the average width: I am doubting rigth now if this is possible ...
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1answer
23 views

Can I make tiles of a raster in postgis?

I am doing some work on dtms in postgis. To import the dtm, I snipped it into tiles and the work directly on the dtm works fine. Then I calculated aspect and slope of the dtm and got some bad ...
3
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2answers
19 views

Can GeoServer Mosaic extension footprints be something other than a shapefile?

According to the GeoServer documentation for the Image Mosaic extension... http://docs.geoserver.org/2.4.x/en/user/tutorials/imagemosaic_footprint/imagemosaic_footprint.html It asks for a shapefile ...
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1answer
29 views

Finding all ways that are partly within a bounding box

I'm trying to write a query that will return all OSM ways which are contained within a bounding box of min/max gps coordinates. I get these cooridinates from the greater london bounding box on ...
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1answer
224 views

ERROR: Operation on two geometries with different SRIDs

I'm new when it comes to GIS and PostgreSQL. I have searched everywhere for the cause of this problem but I can't find the solution. I was following the documentation here First i created a table: ...
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1answer
15 views

PgRouting function wrapper

I'm trying to adapt the pgr_fromAtoB function to pgr_fromAtoMult replacing pgr_dijkstra function to pgr_drivingdistance.Here is the code: CREATE OR REPLACE FUNCTION pgr_fromAtoMult(IN tbl character ...
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3answers
48 views

Postgis installation

I am installing Postgis on my Debian server, following these instructions: http://postgis.net/install/ (Ubuntu / Debian) https://wiki.postgresql.org/wiki/Apt However, after following the ...
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Coloring multilinestringzm M values in QGIS

I have output from a geophysical technique that produces X,Y,Z and scalar value for millions of points, which have been stitched together appropriately (by networkx if it matters) into ...
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14 views

QGIS Plugin for PostGIS versioning

Does anyone of you know a QGIS-Plugin for Versioning PostGIS-Data? I know there was pgVersion of Horst Düster but as far as I know this was not updated for QGIS 2.x (at least not for the "normal" QGIS ...
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1answer
154 views

How to convert PostGis Table (Grid data) to Continuous field using Qgis?

I'd like to transform my Gridded Layer (generated form a PostGIS table of points) to a continuous and colored layer. How could I do this with Qgis or any other program?
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1answer
162 views

Union of several linestring to multilinestring using MS SQL Server

Followed Postgreql query is the existing one used to combine serveral linestring to a single multilinestring. is there any equivalent of this in SQLServer . SELECT ST_AsText(ST_Collect( ARRAY[ ...
3
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1answer
88 views

How to get User and Password of a PostGIS layer from PyQGIS

I wonder if it is possible to get the user and password for a PostGIS database if they are stored in the PostGis connection information. I get the connection information at the moment from the ...
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1answer
787 views

Having trouble connecting QGIS with postgres database with postgis extension

I am working on Ubuntu Precise with postgresql version 9.3 and postgis 2.0. After initially starting my postgres database and eventually getting permission errors that would prevent postgres from ...
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1answer
52 views

PostGIS ST within does not exist

I'm quite new to postgresql and postgis so this error will probably due to some rookie mistake. I want to run the spatial query ST_within. When I describe the query like this SELECT nw.entity_id AS ...
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1answer
21 views

Postgis: Conflation of two vector layers into a single layer

If I have table A that I consider to be definitive and table B that may have some elements missing from table B but also has geometries that are "close" to those in A that I want to ignore. How could ...
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35 views

Find headwater polygons

This is a follow up question to this question. I have a river network (multiline) and some drainage polygons (see picture below). My goal is to select only the headwater polygons (green). With ...
5
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1answer
528 views

Converting polygon values to a vector grid using PostGIS

What is the best way of converting a value from irregularly shaped poylgons to a polygon grid using PostGIS? I have a set of polygons that look like this: and I would like to overlay a grid on ...
5
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2answers
344 views

Find start of river

Edit: Follow-up question here (= Find headwater polygons). How can I determine the start of a river in PostGIS? I have a river network (Multiline) and want to find the startpoints of the rivers. ...
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1answer
12 views

ST_AsLatLonText () rounded

I know this is a POSTGIS question… I set a field with UPDATE members SET latlong_degree = ST_AsLatLonText (the_geom) But the result is (for example) 48°37’41.742”N 9°17’55.716”E The seconds part ...
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1answer
275 views

libgdal1 and libgdal1h conflict

I am on Ubuntu 14.04. When I am installing PostGIS-2.1, it's asking for libgdal1 library. But when I am installing libgdal1, it's removing grass and gdal. Can someone please guide me how to install ...
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123 views

Creating a postgis database a GML application schema

Is there any open Source tool(automated or semi-automated) that converts GML application schema to a POSTGIS database/table .Specifically I have a huge application schema containing many ...
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36 views

postgis - managing single dataset, multiple coordinate systems

I am setting up a forest inventory database that aims to store information about forest plot data from various countries. The current project is in Mozambique, others are in Laos, etc. Each project ...
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How to get changeset tag from .osm file into PostGIS enabled Postgres db

End goal: visualize geographic data from .osm file with QGIS by adding PostGIS layers which include changeset information. I have used osm2pgsql successfully to populate PostGIS and visualize the ...
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3answers
87 views

Spacing a set of points

I have a shapefile of a set of points that I want to space out. I DO NOT want to do this using line interpolation as I run the risk of placing a point where there wasn't one before. I can load this ...
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27 views

How to create unique plane with PostGIS?

How to create a unique plane, with (x , y ,z) as center and a vector as normal, in PostGIS? I already saw "Make3DBox" function, but it does not make a unique one.
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1answer
34 views

Geohash36 for PostGIS

i was wondering if anyone created a ST_GeoHash36 function inside postGIS, i know the ST_GeoHash + ST_GeomFromGeoHash functions exists, But i need the geohash36 function inside postGIS, i need a ...
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2answers
31 views

Can you do aggregate functions among nearby geometry in PostGIS?

I want to do aggregation based not on group but on geometry, is that possible in PostGIS? For example to calculate max, min, average price for all listings that's nearby a geometry point, how can I ...
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41 views

WFS 2.0 transaction

I am using WFS-T in a mobile application to commit changes to a postgis database via geoserver 2.6. I build the http requests myself (not using any framework like geotools or openlayers). I already ...
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1answer
52 views

PostGIS multiple conditional statement on spatial join

I want to make a multiple conditioned spatial query in PostGIS 2.0/PostgreSQL 9.3., OS Windows 7. There are 2 tables, cadastre (Polygon) and roads (Linestring). Query: Select the sum (one number) of ...
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1answer
25 views

Visualising a raster PostgreSQL table in QGIS

I have imported a raster tif image into PostgreSQL with this command: raster2pgsql -s 32643 -I -M filepath.tif -F -t 100x100 public.databassename > filepath.sql And imported the output SQL file ...
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2answers
37 views

Y-coordinates offset in Tilemill

I own a project created with TileMill in SRS 900913. The data source is a Postgis database with the same SRS. When I'm loading the file generated with TileMill (mbtiles) in QGIS and I'm putting under ...
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61 views

Spatial query too slow to handle bigger OSM extracts

I'm trying to compute some statistics for OSM data using PostgreSQL 9.3.5 and PostGIS 2.1.4. I started with a small bavaria extract which I downloaded from Geofabrik. The db schema is the normal API ...
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42 views

Create polygons enclosing same number of points on PostGIS

I have a geodatabase on Postgis with points representing customers, what i need is give a number of customers, lets say 100 and it need to generate polygons enclosing 100 clients each one. I only ...
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122 views

N Nearest Neighbours efficiently PostGIS/Python

The data is worldwide about a million points, lat/lons, with an id and an importance value (0.0 to 1.0), and it's limited to being on land. Ideally I need to cluster all 1 million points into 100,000 ...
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17 views

Convert Postgis tables to DWG

Is there a simple way of converting a postgis table to DWG for a given table name? Regards,
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1answer
81 views

PostGIS ST_Union Performance

I'm trying to execute a 'dissolve' operation in PostGIS using the ST_Union command. The input layer is admittedly quite large and complex. By 'large' I mean 57,771 features, with number of vertices ...
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1answer
200 views

ST-Links convert Feature Class to DB Table error

I'm using ArcMap with the ST-Links SpatialKit Conversion tool to convert a Feature Class to a DB Table. But I'm getting an error: ERROR: 42601: type modifier is not allowed for type "geometry". I ...
2
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1answer
273 views

Using ST_MakeEnvelope over the dateline

I'm using ST_MakeEnvelope in PostGIS to try and make geometries that cross the international dateline, but they are making a shape that wraps the other way around the globe. The geometry I want is ...
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1answer
95 views

Openlayers wfs no fid being passed from tinyows

I have a webapp - OpenLayers<->tinyows<->postgis. With 1 layer I have a problem. On localhost all works well - here is a snip of the xml I get back: <gml:featureMember> <tows:trad ...
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2answers
33 views

Problem in importing shapefile to Postgis with postgis Shapefile manager

i have a problem with importing my shapefile to postgreSQL, it's a poroblem with the encoding, here's the screenshot: i tried to change encodingin "options" buti get this message: "Failed in ...
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3answers
64 views

How can I export data containing umlauts from PostGIS to shapefile, without losing the umlauts?

I am exporting my Finnish (Finland) data from PostGIS to esri shapefile. I am using the PostGIS Shapefile Import/Export Manager and I don't see any way to specify the encoding of the shapefile's ...
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1answer
199 views

Polygon grid shape file for landmass

I am interested in generating a polygon grid shape file for the landmass of the world. What I have presently is two tables in postgreSQL. Table 1: Coastal area shapefile ...
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1answer
50 views

How to display OSM relations (in QGIS) from osm2pgsql populated PostGIS DB

I have a PostGIS DB populated with OSM data (osm2pgsql, standart.style). Now I would like to display a hiking trail (http://www.openstreetmap.org/relation/51855). It would also be fine, if I just ...
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196 views

Coordinate System Google Maps API

I am making an application in java using GMaps4JSF where the person will enter the address on the map I'll take this coordinate and consult on my postgis base regions in which region this point is ...
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1answer
35 views

PostGis - BBox -vs- ST_intersects Queries

CartoDb Recommend here that the following query is faster than an St_intersects Query SELECT * FROM {table_name} WHERE the_geom && ST_SetSRID(ST_MakeBox2D(ST_Point(-73.9980, 40.726), ...