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

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Routing Application in Windows

I am making an routing web application similar to Google Maps 'Get Direction' feature. But because of the limited control and data on GMaps, I decided to use OpenStreetMap instead. This also made me ...
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45 views

can geoserver select one of many rasters from a postgis table

I have a postgis table with many different rasters in it. Is it possible for geoserver to grab only one of the rasters from the table based on something like a where clause?
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GeoDjango: AttributeError: function 'GDALAllRegister' not found [closed]

Im trying to get started with GeoDjango. I am using this https://docs.djangoproject.com/en/1.8/ref/contrib/gis/tutorial/ tutorial. When I run "python manage.py migrate" This error occur: ...
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2answers
208 views

QGIS opening file - Very slow on POSTGIS databse with many layers

When opening a qgis file with many layers (20 or so) it takes +5 minutes to load. All the layers come from a single PostGis database. When looking into the server logs, i see that there are many ...
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1answer
326 views

How to calculate the optimum bus route using pgrouting?

My setup for my web page is OpenLayers, Postgresql/postgis and pgrouting. What I do not understand is how I am going to do the routing.I have read many tutorials but I don't understand what my next ...
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1answer
113 views

How to compute a line intersection point in a street layer in postgis 1.4?

I have a street layer downloaded from osm. I need to calculated intersection point as we do in qgis from vector menu -> Analysis tool -> Line intersections. I am new to postgis/postgres. any how i ...
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1answer
213 views

Problem with using a circle as polygon for querying PostGIS

I'm trying to query PostGIS and find some object features that intersect with a circular buffer created by the user using OpenLayers, JavaScript and PHP. I use the following code for creating the ...
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3answers
307 views

Query to find the Intersection coordinates of multiple Polyon

I am using the below Query to find out the intersection coordinates of 2 Polygon and its working fine,but how to use or modify the query to find the intersection area coordinates for multiple(or N ...
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5answers
3k views

Unable to install the PostGIS extension to PostgreSQL on Ubuntu 12.04 LTS

I just installed Linux Ubuntu 12.04 LTS (on a virtual machine). I then successfully installed the PostgreSQL 8.4 database management system. I am now trying to install PostGIS, which is an extension ...
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1answer
887 views

From a trajectory of GPS points to a multiline segment

Given a trajectory as a sequence of GPS points I would like to create a smooth linestring representing a path where a car drove. The data is stored in postgresql: the input trajectory in a table, ...
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1answer
1k views

How to create shortest route and multiple routes service using openlayers?

I created a digital database of many important features and locations of my city. and I want to create a web application in which shortest distance between two locations can be calculated and ...
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2answers
4k views

mulitlinestring to linestring

I am using postgres with postgis and I have a set of points which I would like to interpolate with a set of lines. Now my problem is that the set of lines are of type multilinestring. Is there a ...
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1answer
303 views

Howto setup osm2psql

I'm following these instructions to setup osm2psql . I need it to import osm data file inside a PostGIS DB. The following steps worked fine: createdb -E UTF8 -O user mydb createlang plpgsql mydb I ...
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2answers
3k views

How to offset point perpendicular to line direction in PostGIS

I have a postgis table of points, that are sitting on road centerlines (I've linear referenced them). And the second table with road centerlines themselves. The point table also has a field roadid and ...
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0answers
718 views

How to add ECW support to GDAL bundled with PostGIS Windows

I'm currently trying the new raster functionalities of PostGIS 2.0 and I successfully imported some GeoTIFF file into PostGIS (although it only find one band so it's all black and white for some ...
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1answer
123 views

Find nearest node function

I am trying to get work the next function but i don't know if it is incomplete because the query SELECT * FROM pgr_nearest_node1('jaen',-3.75,37.779); does not provide any results. Here is the ...
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1answer
205 views

How to union polygons and add attribute values of combined output features

I have a layer containing 10 polygons all overlapping at various locations. Each polygon has a value of '1' in a column called "value" How do I Union the polygons (rows) together such that the ...
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0answers
69 views

Is there any feature limit for Spatial data migration to Postgre SQL9.2…?

I am trying to migrate spatial data to Postgre SQL9.2 using 'Postgis Shapefile & DBF Loader 2.0'....Each time it returns a "Runtime error'. Primary data extension - .shp ; Data type - ...
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2answers
6k views

What is the unit used in ST_Distance()?

I wonder what the unit is of the float being returned from ST_Distance. In the documentation it says: ...cartesian minimum distance (based on spatial ref) between two geometries in projected ...
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3answers
4k views

How can I get the geometry length in meters?

The ST_length() function returns the length of a linestring but not in meters. Is there a function like ST_Length() but in meters?.
7
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1answer
144 views

Georeference raster in non horizontal plane

We have raster data which is generated from (vertical) walls. We would like to keep this data in a postgis database and have the spatial reference encoded "the most accurate way". Currently, they are ...
7
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1answer
974 views

How is ST_PointOnSurface calculated?

The PostGIS documentation states that ST_PointOnSurface returns "a POINT guaranteed to lie on the surface". It seems like this function could be trivially implemented to give results that satisfy the ...
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1answer
966 views

Error when using pgsql2shp

I try to export geographical data from a postgis database to a shapefile with pgsql2shp. Normally this works fine, but now I receive the following error. Preparing table for user query... Done. ...
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2answers
464 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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4answers
4k views

Importing .shp to postgreSQL

I want to import a shp file to postgreSQL. First I create sql file and then run PostgreSQL. To create sql file, I run this command in windows cmd: shp2pgsql -s 4326 worldCountries.shp worldcountries ...
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2answers
573 views

QGIS saving analysis output as Postgis table

i am using QGIS and Postgis together. I can load data in Postgis and than i import it to QGIS. But i am trying to save an analysis output (example: buffer analysis, voronoi polygon or SEXTANTE ...
6
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1answer
978 views

QGIS WKT Raster Plugin error, what does this mean?

I have been playing with the WKT Raster plugin. I have installed the WKT Raster experimental binaries in PostGIS successfully and followed the instructions in the read me to the letter. When i am in ...
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1answer
64 views

1-center and k-center problem / maxmin facility problem in Post

is there anybody who has already solved the 1- and k-center problem within PostGIS (optionally with distance metric obtained by pgrouting)? References: 1-center problem in Wikipedia and graph ...
5
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1answer
147 views

Can I identify if a point is inside a volume in PostGIS?

We are currently investigating PostGIS as an option to look up three-dimensional blocks which contain a point (and later also lines). At this point in time I cannot see any functionality that operates ...
5
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1answer
673 views

How to achieve equivalent to Dissolve from ArcGIS for Desktop using ST_Union?

I am trying to achieve an equivalent to the Dissolve tool from ArcGIS for Desktop using ST_Union from PostGIS but it seems I am not getting expected result. I have one table which has certain ...
5
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4answers
6k views

How to convert multipoint layer to point

I have a Spatialite layer which is multipoint (following a QGIS Save As from shapefile). I need it to be PostGIS and POINT. I have tried ogr2ogr -nlt POINT and got 'new row for relation "xxx" violates ...
5
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1answer
492 views

How to connect particular sets of points with (poly)lines?

I think my problem is quite easy to be solved by the most postgis-users, but i am a bloody beginner: i have a timestamped point-table representing GPS-tracked places of different cars. To distinguish ...
5
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1answer
1k views

Why do TIF loaded into PostGIS lose their colormap?

I have successfully loaded a TIF image (using raster2pgsql) into my PostGIS 2.0.1 database. I can load the raster image into QGIS and it displays in the correct space. However, it has lost all colour ...
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4answers
2k views

OSM To Postgis & WGS84 problems

I’m trying to import OpenStreetMap (OSM) data into postGIS it doesn’t appear to be working in that features do not appear to be in the correct place.. Using the QGIS OSM add in and a coastal shape ...
5
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1answer
409 views

How to filter points based on proximity while inserting into PostGIS?

I have a large amount of locations that need to be inserted to a PostGIS database. However, I'd like to aggregate these points so that if there's already a location, say nearer than a kilometer, then ...
5
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1answer
758 views

How to get GeoNetwork to search through PostGIS fields via GeoServer WMS

I can't seem to get GeoNetwork to search through my PostGIS fields via GeoServer WMS. According to the GeoNetwork Documentation: it should loop over datasets served by the service and produce ...
4
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1answer
45 views

PostGIS point distance from polygon not 0 when on edge

I have a pretty simple problem: SELECT * FROM ST_Distance(ST_GeographyFromText('POLYGON((70 -40,70 -39,71 -39,71 -40,70 -40))'), ST_GeographyFromText('POINT(70.48 -39)'), False) returns ...
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1answer
59 views

PostGIS > Intersect two circles. Each Circle must be built from Long/Lat degrees plus radius

I'm trying to figure this out, so I wanted to try asking to the experts. This question is related to PostGIS (from postgresql). What I want is: 1) Based on a longitude and latitude I want project ...
4
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1answer
110 views

How to interpolate missing data from neighbours in PostGIS?

I have a dataset with point data within a given country. Let's say my dataset looks somewhat like this: tree_id | species | age | geom ------------------------------ 0 | Ash | null| ... ...
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1answer
264 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 ...
4
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1answer
1k views

Extracting centerline of a Complex-Polygon in PostGIS/Python

Any idea how to extract the centerline of the following polygon (Fig1) using PostGIS functions or Python modules? I was trying Voronoi Function but thats not helpful for this kind of shape. I want ...
4
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2answers
222 views

Can't get Tiger Geocoder to work in PostGIS

I've installed the PostGIS Tiger Geocoder according to these instructions and loaded in data for the state of New York. Unfortunately, when I try to geocode something... ny_tiger=# SELECT g.rating, ...
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2answers
8k views

Installing postgis on postgresql 9.1 not working

I'm trying to install Postgis 2.0 on a perfectly functionig postgresql 9.1.10 database. I installed the package via: richard@srv1:/$ sudo apt-get install postgresql-9.1-postgis postgis Reading ...
4
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1answer
2k views

PostGIS Dissolve/Union close polygons

I have approximately 1 million polygons that have been split by lines. However, this has caused one half of a polygon to be separated by approximately 50cm from its other half. After doing a lot of ...
4
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1answer
113 views

Why does only one of the following queries throw an error?

There are 2 SQL queries: SELECT wkb_geometry FROM building_polygon WHERE ST_Contains(wkb_geometry, ST_GeomFromText('POINT (29.4 60.1)')); SELECT wkb_geometry FROM building_polygon WHERE ...
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4answers
1k views

Create a point x meters from origin using st_translate in postgis

How do I create a point 1000 meters away from a reference point? The ST_Translate only supports geometry type. I also tried using ST_GeomFromText but that returns a unit and not in meters. Here is ...
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3answers
847 views

How to find out what features /tags are included in an .osm or .pbf file?

I would like to load osm data into a postgis (postgresql) database. In How to load OSM data into PostGIS preserving all Tags? there has been a solution posted: Download the OSM files (in .osm ...
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2answers
3k views

How to select segment of linestring using PostGIS?

i have PostgreSQL+PostGIS. I have a linestring: "LINESTRING(60.7014631515719 56.8441322356241,60.7023117507097 56.8445673405349,60.702948200063 56.8447993944193,60.703902874093 ...
4
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1answer
262 views

Update PostGIS after updating GDAL?

I am using PostGIS 2.0 and I want to use the raster functionality through mapserver. It seems as if the latest official GDAL release 1.9.1 has an unstable PostGIS raster driver, as pointed out in a ...
4
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1answer
1k views

How to save a newly created shapefile in PostGIS?

I am creating shapefile using shapefile.py and my database has records more that 65k which is the limit of the shapefile. How can I create shapefiles then? Is it possible that somehow I am able to ...