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

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How can I use ST_Contains/ST_Overlaps with non-simple lines?

Following the SQL of the accepted answer to How to get smallest line segments from intersection + difference of multiple overlapping lines? copied below. I'm having some difficulties assign the ids of ...
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Is PostGIS / PostgreSQL UK Public Sector Network (PSN) compliant?

Is PostGIS / PostgreSQL UK Public Sector Network PSN compliant? ... specifically so it can be used in a UK local government council?
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PostGIS: intersection of a MultipolygonZ and a floating point raster

I am trying to isolate the pixels in a floating point raster (loaded in PostGIS) that intersect my MultipolygonZ table (also loaded in PostGIS) and whose values are less than or equal to the z values ...
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55 views

How to IDW interpolation in PostGIS

I'm trying to find PostGIS Raster functions supports the Inverse Distance Weighted interpolation method (IDW) and Kriging interpolation method. I'm especially trying to generate a temperature map ...
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45 views

Copy Polygon to Postgis from Shapefile

I have the following situation: Postgres database with PostGIS There is a table with a PostGIS geometry column. All non geometry data is managed (create, update, delete) by a webapplication. QGIS ...
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48 views

Problem with ST_Union

I have loaded some rasters into Postgis. I did a lot of ST_XXXX (scale, snap to grid,resample) magic to make them aligned. After executing: select r1.rid,r2.rid ...
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19 views

How to use the TopoViewer in the QGIS DB Manager?

I'm just wondering what the TopoViewer in QGIS is doing. DB Manager (PostGIS) says 'Schema "schemaname" is not registered in topology.topology'. Unfortunately there is no help available and I can't ...
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27 views

Incorrect results returning from st_distance_spheroid query

Given a routable network table constructed by completing the guide at http://anitagraser.com/2011/02/07/a-beginners-guide-to-pgrouting/, how can I get an accurate list of all roads that are within a ...
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44 views

Are GIS tools suitable for physical capacity and placement management?

I'm a complete newbie to GIS systems, I've been watching some introductory videos about GIS but I'm not yet sure if GIS tools are the right tool for solving my problem. I have a database with ...
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33 views

update query with st_intersects() is not finding results

So I am trying to identify which items from the requests table fall into some particular district from the district table using postgis. Basically, I am writing an UPDATE query that will take the ...
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25 views

PostGIS Street Intersection Autocomplete with full text search

What I'm attempting to do is create a custom autocomplete for addresses, road intersections, POI's, etc. For now we are going to using Mapbox GL (we'll be creating a custom map at a later phase), ...
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Django/PostGIS: How to insert coordinates in PointField in EPSG:27700, and return EPSG:4236?

I am using Django 1.9 with PostGIS. I have input data that consists of British National Grid eastings and northings, and a table that looks like this: class Org(models.Model): name = ...
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Problems using pgr_fromAtoB - postgresql error

I have some trouble with the pgr_fromAtoB function of the workshop. I get: ERROR: column "ways" does not exist But "ways" is the table, not a column. What am I do wrong? My table ways looks like: ...
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37 views

PostGIS query: filter rows by area?

I am working with PostGIS (in CartoDB). I want to find all rows in the database with an area of over 100 square metres. I've been trying this: SELECT *, ST_AREA(the_geom::geography) AS area ...
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31 views

Import raster using raster2pgsql with out-of-db option not working

I am using raster2pgsql to import DTED data into postgis database. I would like the data to be out-of-db, I am using the command as follows. raster2pgsql -R /home/gis/elevation/DTED/area.dt2 ...
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ST_Intersects in postgis

My version : postgres 8.4.1/postgis 1.4.0 I want to perform a simple spatial join with the following query : SELECT code_insee, nom, id_canton, lib_canton FROM localisants.alca_toponyme_commune ...
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64 views

QGIS - Alternatives to Offline Editing Plugin

I am looking for a way to edit my postgis layers offline (in field) using a Microsft Surface Tablet. I have been testing the "Offline Editing Plugin" unsuccessfully. These are the issues I have ...
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27 views

St_intersects returning false results in postgis

I want to intersect point geometry with raster. In postgis I'm executing select st_intersects(geom,rast) from testraster1,pft_pft and the result is false even though the points are sitting on ...
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39 views

QGIS crashes when using PostgreSQL/PostGIS triggers

When using PostgreSQL/PostGIS triggers saving layer edits gets slower and slower every time when saving a layer edit. This issue occurs after a few up to a few dozen saved layer edits. Finally QGIS ...
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31 views

PostGIS: Find nearest point given coordinates from another table

So I have two tables, one table is called stores which has the name of the store as well as the geom column that contains the coordinates for the stores. The other one is customers which has the ...
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27 views

pgrouting pointAtoB function

Has anyone successfully implemented pgr_fromAtoB function? Sometimes I get 0 results from points in the same line string, sometimes I do get results, How can accuracy be improved?, or maybe do I ...
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127 views

Visualizing shapefiles on web using SHINY package of R with PostGIS?

I am using PostGIS database to store my shapefiles. Now I want to read those files through shiny package of R. How can I visualize those files on web using shiny package of R and perform statistical ...
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How to calculate multiple distances between set of points and vector grid in PostGIS?

My set contains the following input data: A set of points and a hexagonal (vector) grid. For each cell in the grid, I want to calculate the driving-distance to each point. I thought this would be a ...
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51 views

Length not respected in ST_Segmentize

When segmentizing a geography line in Postgis, the max segment length does not seem to be respected when the line is more than 3000km. The error grows when the length of the line increases. Below the ...
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48 views

Multi-dimensional points in PostGIS

I have experience in PostgreSQL but I am fresh new in PostGIS and I can see how quickly would I like it. I have extensively worked on time series and now I am discovering the spatial side of my data. ...
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Automatically generating raster maps (from OSM) for areas bounded by polygons?

In order to create walking lists for a volunteer campaign I have used qgis to draw polygons over groups of addresses. These are irregular areas, so I've used postgis's ST_ENVELOPE function to ...
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31 views

Nearest neighbor POSTGIS in FME

So I have an attribute and I want to find the nearest neighbor but the issue is that the memory of the server may not be able to handle the use of all the FME transformers. I need to take records out ...
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55 views

POST (OL3-->Geoserver 2.8.1-->PostGIS 2.2)

I have a problem with post. Here is code OL3. (multi platform hybrid app - cordova) var point = new ol.geom.Point([18.25, 49.83]); var feature = new ol.Feature({ geometry: point }); ...
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Creating a contiguous raster stack from different sources (vectors and DTM bands)

This is a conceptual question I've been trying to implement for a while, and not being very good at raster/data processing or python I'd like to hear best practices in dealing with an extent such as ...
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31 views

How to translate QgsMapCanvas coordinates to wgs-84?

My application uses QgsMapCanvas. I've got point coordinates in wgs-84 crs and i need to add this point to vector layer (represents postgis table) inside of the canvas. Have no idea how to ...
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43 views

Updating an Openstreetmap PostgreSQL database after the system restore

My Openstreetmap PostgreSQL database takes a long time – about 25 hours by now – for updating via Osmosis after I had made a system restore at the last weekend. Before making the system restore it ...
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35 views

How do I translate gps sports data into a representative plane

I'm hoping to use qgis and postgis for a project but I'm unsure of, how to not only frame the question but accomplish the task. If I have gps data from 1 runner on an oval track but who has run on ...
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40 views

Find census block for street intersection with tiger geocoder

I'm geocoding lots of addresses and map them to census block. Some of addresses are street intersections, like this select ST_X((geo).geomout)::numeric(8,6), ST_Y((geo).geomout)::numeric(8,6) ...
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59 views

How to draw a raster over the World using Postgis

Im currently working on a system to track user interaction on mapwidgets. Now i need to visualize the bounds that users are looking at on the map. Since were using a whole lot of data i need to find a ...
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37 views

Creating look up tables in QGIS that last more than one session?

It seems that when I create a Look up Table or Value Map for a shapefile or a PostgreSQL table in QGIS it saves it for one session, then when I open it again it had disappears. Can someone ...
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31 views

pgr_nodeNetwork doesn't place new nodes properly

I wanted to use pgr_nodeNetwork tool to split lines where there's no vertex on intersection. The tool doesn't seem to work as expected, though. It doesn't place new nodes right where the two lines ...
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81 views

Unable to load raster from PostGIS into QGIS

I'm trying to load raster from a postGIS connection into QGIS, but I'm getting the following error: PG: dbname=EnvModel host=127.0.0.1 user=postgres port=5432 mode=2 schema=public column=rast ...
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48 views

refine nearest_node with radius-distance ( ST_Distance, ST_DWithin )

i am a hobby-IT-person and currently stuck with some simple problem, maybe somebody can help me: This is my working POSTGIS-function, source by underdark: ALTER TABLE distance_graz ADD COLUMN ...
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65 views

clip raster with polygon in postgis

I am newbie in postgis. I have a raster landsat images in table "ras" and a polygon shapefile image in table "shp". Now I want to clip raster with polygon using postgis, but I have a problem The ...
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48 views

PCA on correlation matrix in PostgreSQL

Does anyone know how to perform PCA using PL/pgSQL in a PostgreSQL function, considering correlation matrixes of potentially high order? Maybe a specific library for this problem... Thanks.
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How to get azimuth and altitude from a 3D surface in PostGIS?

I would like to know the azimuth and tilt of a polygon / surface in a PostGIS database. The azimuth should be given e.g. from 0° to 360° degrees. The altitude should be between 0° to 90°. An example ...
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54 views

raster2pgsql stops at line 53 at RETURN

I am importing some very large rasters (in the tif format) into Postgres SQL (9.3) using raster2pgsql on the command line. Most of the rasters imported fine, some had to be converted to the img format ...
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SRID of geoemtry exported in PostgreSQL with ogr2ogr

I use ogr2ogr to export geometric data from EDIGEO files to some PostgreSQL table in append mode, but the output geometry SRID is always set to zero. Can I do something to specify the output geometry ...
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33 views

Select query St_asBinary(rast) returns out of memory for query result

I have very large rasters (7000x3500 cells) in postgis (2.1.3) postgres (9.3.4) that I want to pull down via psycogp2 and create numpy arrays and ultimately a geotiff. Initially I found I had to use ...
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Why is the geometry changing slightly when I import shapes into a postgresql database with postgis?

I recently posted this question when first trying to import data from a file geodatabase into a postgis database: how can I maintain curves when converting from geodatabase to postgresql using og2gui ...
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51 views

In QGIS Python console how can I calculate given the distance, bearing and initial point, the final point

In QGIS Python console, how can I calculate the location of a final point, given a distance and bearing from an initial point? In PostGis I see that it is ST_Project, however I would like to do it ...
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Combine two parallel lines to one with postgis

In OpenStreetMap, a highway=motorway consists out of two parallel lines, each representing one direction: On a professional map the two lanes get combined to one single line and drawn with a middle ...
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41 views

ST_Intersects does not use spatial index

I wrote this part of code: SELECT CB.id_2 AS CountyID, CA.id_2 AS NeighbourCountyID FROM "Counties10B" CB,"Counties10" CA WHERE ST_Intersects(CA.geog,CB.geog); But it does not use spatial index. ...
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Import postgis layer from S3 link

I have a postgis layer (layer.sql), which I am trying to add to my postgres database (mydatabase). The postgis layer is stored on S3 (https://s3.us.../layer.sql). I can add the layer to my database ...
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72 views

Create HexBins for shapefiles

I usually create hexbins using the MMQGIS tools in QGIS. I would create a hex layer and intersect it with a shapefile. I've tried to create a hex shapefile and importing it into a PostGIS and tried to ...