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

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Postgis - Split linestring between point A and B

I need to find the different trajectories between point A and B. In the image is possible to see 2 differents trajectories. The way i use to calculate them is: Found the min time and the max time (in ...
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81 views

What is wrong with my WFS-T protocol setup?

So I want to transfer some Vector Layer Features from javascript code to my geoserver and then to postGIS, my code looks like this: saveStrategy = new OpenLayers.Strategy.Save(); ...
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Comparing and updating two large tables

I'm using CartoDB to sync the status from tables using a common ID on each one. The problem I found it's the tables are too large, over 29k rows. Here is the query I'm using and the gives me an ...
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27 views

Error in querying data

I have a mapserver file as below , I get blank page with no map executing this query: NAME var DATA xyz STATUS ON TYPE POINT DUMP TRUE ...
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61 views

Clustering the WGS84 point features (projection transformation aspects)

My question is quite trivial and was discussed many times before (like here) but in our case it has the confounding extra requirements... The list of sparsely distributed 2d point features is stored ...
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125 views

All map services display pink tiles

I have implemented mapserver in Ubuntu 14.04 with postgresql 9.3, postgis and imposm using GitHub tutorial. After completing the tutorial all map services display pink tiles not map info. i was not ...
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58 views

List of vector to one raster in PostGIS

Hi PostGIS developers! I need to rasterize a part of OSM map by coordinates. I found rather good algorithm, but can’t finish it. I have problems in STEP 3. I described all algorithm here – may be ...
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69 views

Create geometry column of type 'PointZM' in PostGIS

I want to add a geometry column with geometry like "PointZM", "PolygonZM". I have written something like this: SELECT AddGeometryColumn ('data_rivne','geo_point','geom2',0,'POINTZM',0); But it ...
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Convert multiline to polygon

perfect result Shapefiles How I can convert this closed line to polygon with PostGIS? I tried many functions like ST_Polygonize, ST_MakePolygon, ST_BuildArea. I got some results, but not a perfect ...
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Finding areas with high POINT density from PostGIS table using Python

I have a PostGIS table with thousands of POINT objects and I want to find areas that have a high density of points. I have the DBSCAN clustering algorithm implemented in Python which does exactly ...
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57 views

Why does the postGIS file lose geometry?

I am loading shapefile data from a GPS into PostGIS via Leica ZenoOffice. This apparently imports fine with it's geometry in the attribute table. However, when I add a postGIS layer in QGIS the file ...
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Create “grid” of polygons with the same 3D area based on an underlying raster variable (e.g. DTM height)

This could apply to point or raster values but imagine a raster of a continuous variable such as height (DTM). Is there a way to create a complete coverage of polygons that will have an equal area, ...
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Error when trying to visualize geography data with QGIS

I use PostGis, and want to use QGIS to visualize data. But I get error message when trying to show the points in the table. I create a table: CREATE TABLE poi ( id text NOT NULL, coord ...
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48 views

Which type in entities for PostGIS/Hibernate Spatial

I already manage to store, read and update PostGIS rows with Hibernate Spatial with a Point and a MLineString in a very simple case : a MLineString defining a road, display a point along this road ...
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27 views

How can I associate a consistent polygon area with a set of attributes using a topology?

Consider the following topology. SELECT CreateTopology('topotestschema', 0, 0.01); CREATE TABLE topotest (id SERIAL PRIMARY KEY, data TEXT); SELECT AddTopoGeometryColumn('topotestschema', 'public', ...
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47 views

Join/append multiple, identical polygon layers into a single layer whilst retaining all attributes?

I have run some analysis (zonalstats) on different raster layers using the same analysis polygons. I want to concatenate all these different layers together, i.e. retain a single polygon and have a ...
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40 views

Postgis Raster Unions Color Issues

Can someone explain to me what I am doing wrong here as I think I do not properly understand postgis raster bands. I have a set of geometries that I want to merge with a raster and created a raster ...
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37 views

How to dissolve inner polygons in a multipolygon

I'm trying to get the boundary of a collection of zip codes. Here is my current sql: SELECT ST_AsText(ST_SimplifyPreserveTopology((ST_Union(geom)), .003)) as poly FROM zcta5_data WHERE zcta5 IN ...
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PostGIS Raster functions not working

Hopefully I have a simple question that I'm not phrasing correctly in google. I'm trying to learn about storing and producing rasters in PostGIS. There are tons of examples and documentation online ...
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127 views

Undefined symbol error when creating postgis extension

When trying to create postgis extension, I'm getting an error, no references in google on it. maptest=# CREATE EXTENSION postgis; ERROR: could not load library "/usr/pgsql-9.3/lib/rtpostgis-2.1.so": ...
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157 views

Editing PostGIS data in ArcGIS Desktop?

Quick question regarding editing PostGIS data in ArcMap 10.0. Far as I can tell, this can only be accomplished through third-party plugins like GISSquirrel or ST-Links. Does anyone know of an ...
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98 views

Merge overlapping GeoJSON GeometryCollections

I need to merge three overlapping GeoJSON GeometryCollections of Polygon. Ultimately, the end result needs to be a geom type for PostGIS (e.g. MULTIPOLYGON) so I can easily check if particular points ...
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82 views

How do I automatically generate a spatial data catalogue from shape files and .gdbs?

I've recently inherited a whole bunch of spatial data (mostly shapefiles but some .gdbs) which relate to a bunch of different cities. I'm looking for a way to take an inventory of what data I've got ...
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PostGIS points to multipoint error

I have a table on PostgreSQL 9.2 ("POSTGIS="2.0.1 r9979" GEOS="3.3.3-CAPI-1.7.4" PROJ="Rel. 4.8.0, 6 March 2012" LIBXML="2.8.0""). This is it: CREATE TABLE nearest_point ( id_nearest_point serial ...
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Is there a Raster2pgsql GUI?

Has anyone ever attempted to create a raster2pgsql gui (like the shp2pgsql gui). As I am sometimes lazy to use command line, this could be a very nice to have.
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153 views

Can't see Postgis layers added to QGIS

I'm trying to transition from an old Postgres/Postgis database to a new one. I'm working in a fresh install of Win 7 64 bit. I installed Postgresql 9.3 32 bit, then installed PostGIS 2.1.3. I created ...
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101 views

Collapse dual carriageway lines in PostGIS

I have OpenStreetMap data, which represents larger roads (e.g. dual carriageways, aka divided highways) as parallel lines. The question is answered for ArcGIS or Skeletron here, for example using ...
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73 views

Add polygons to PostGres to be queried by Nominatim

I'm trying to build out a geocoder that also returns the correct legislative district information from this data: http://www.census.gov/geo/maps-data/data/tiger.html I've got OSM data imported into a ...
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92 views

Open PostGIS layer with QGIS 2.2

I just upgraded QGIS from 1.8 to 2.2 and I am getting some troubles to open a PostGIS Layer. The connection with the server works fine, I can see all my tables, select the one I want to open and even ...
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58 views

PostGIS raster connection is not closed by MapServer

I'm using PostGIS raster in MapServer like this: TYPE RASTER DATA "PG:port=6432 dbname='mydb' user='postgres' password='1234' schema='public' table='truemarble' mode='2'" PROCESSING ...
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71 views

Implement a least cost path in a graph

I am trying to produce a routing functionality in a web-GIS that, given a start and an end point, will retrieve the least cost path taking into account points along edges representing major costs, ...
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Import raster to postgis and add a foreign key constraint

I use raster2pgsql to import raster files into a table with this command line: C:\Program Files\PostgreSQL\9.3\bin>raster2pgsql -s 4326 -M -F -a c:\temp\mun.tif public.basqui_raster | psql -U ...
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Gaussian plume model in PostGIS or geocouch

Does anyone know of existing code for dispersion modeling using Gaussian Plume or comparable model, that I could plug in / adapt to be used programmatically from PostGIS or alternatively via ...
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159 views

Why does QGIS crash when my PostGIS table has a primary key?

Configuration: PostGIS Library: 2.0.3 GEOS: 3.3.8-CAPI-1.7.8 Proj: Rel. 4.8.0, 6 March 2012 PostgreSQL 9.2.2, compiled by VC++ build 1600, 64 bit, running on Win2012 server 64 bit QGIS 2.2.0 - 32 ...
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Point in Polygon operation for 100G of data

I have lat/lon point locations for over a billion points, all based in the US. For each point I would like to generate a dataset that links them to their county and to their MSA according to US Census ...
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PostGIS automatically creating geometries after importing using QGIS DB Manager

I have a shapefile consisting of linestrings, in which some of the features have null geometry. Yet, after importing it to PostGIS, using QGIS' DB Manager, a geometry is created for those features ...
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Use pgRouting with a PaaS

Is it a way to use a postGIS/pgRouting enabled database with a PaaS like Windows Azure? If not, do you know alternatives?
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Focal Mean of neighbors using ST_DWithin on points in PostGIS

I'm trying to calculate focal means on a grid of points in PostGIS. I know that a raster calculation would be more efficient, but I only need to run the algorithm once to get the data, so I don't ...
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59 views

PostGIS 3D Extrude function

I selected buildings from OSM (which represents my city). I insterted a new column 'height' and I filled with a random number exactly number 2, so every building have 2metres altitude. Buildings are ...
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How to simplify a polygon down to X amount of points?

If I have a polygon that has 100000 points, how can I calculate what the tolerance should be to simplify it down to 1000 points using ST_SimplifyPreserveTopology?
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101 views

qGIS' Database Manager “Load as New Layer” Option Not Working

I'm trying to visualize some of my database queries on qGIS. I run a valid SQL query which returns a subset of my table that should be easily loaded as a layer. I then check "Load as new layer," ...
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Query from plugin that shows result on Map and in Attribute Table

I'd like to create a plugin that performs a static (no user input required) query that, based on a condition, selects all the features on the map and displays these in the attribute table. I have the ...
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45 views

Problem installing Aggregate Polygons Function in PostgreSQL 9.3

I'm new to PostgreSQL and I've been trying to run a sql function written by Dr. Horst Duester, found in http://www.kappasys.ch/cms/index.php?id=65&L=5, which is used to aggregate detached ...
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91 views

Geoserver WFS Fails to Load in OpenLayers

I'm working with Postgis->Geoserver->openlayers on localhost. I followed a Geoserver tutorial to import some nyc sample data into my postgres/postgis database and link it to Geoserver. The layer ...
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ST_SplitRight() in PostGIS?

I am looking to split a shapefile via a line. I am interested only in the feature that lies to the right of the line; exactly what ST_SplitRight does here. Do any of you know of a way to do this in ...
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82 views

Do ArcGIS clients that direct-connect to postgresql/postgis databases override configuration settings?

I went in to modify some settings on a Postgresql database via the PGAdmin config editor and some of the settings don't have their default values and they are higher because they've been overridden ...
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Broken PostGIS support GDAL

I'm having some problems with Postgres/PostGIS after rebuilding my GDAL library:( I wanted to add MrSID support in GDAL so rebuilt it with the MrSID SDK. Everything compiled ok and I am now able to ...
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68 views

How to define Z dimension on table with PostGIS for import in TileMill?

I'm trying to reproduce the idea behind this blogpost from Mapbox, but with other data, for example the ne_10m_populated_places_simple dataset from Natural Earth. By adding a z-dimension to the data ...
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How to SELECT one day's scene (Landsat 8 scenes)

I have a huge dataset of raster in PostGIS. Each scene is divided into tiles (tile-size 500x500). I was trying to SELECT rast FROM landsat8 WHERE ST_Intersects(rast, polygon). It runs very slow, ...
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132 views

PyQGIS Dialog Plugin not resetting

I have written a PostGIS search plugin that works pretty well, except two things that I just cannot figure out a solution 1) When the dialog closes and then is reopened the previous query is still in ...