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

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PyQGIS - load PostGIS layer as editable

I can load a PostGIS layer on QGIS' map canvas but "Toggle Editing" button comes "inactive". How can I load vector layer as editable? The code given below loads PostGIS layer on map canvas & ...
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94 views

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
110 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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206 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
452 views

Configuring SFCGAL to PostGIS Db

I was using PostgreSQL with PostGIS and Pgrouting. Recently I needed to install SFCGAL for some extra functions for my PostGIS db. After installing SFCGAL, now I don't know how to update my PostGIS db ...
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101 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
174 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
210 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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725 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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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
3k 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
288 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
2k 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
630 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
79 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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169 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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1answer
351 views

overlay my shapefiles stored in database to the web/browser [duplicate]

I am very much strrugling on how to display my shapefiles stored in postgis database to the browser or to the web.. is there anyone there knows how to do it.? I am using geodjango framework in ...
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3answers
4k views

QGIS, Postgis: Geometry type does not match column type

I'm trying to import some polygon shapefiles to Postgis in QGIS via SPIT. One of them can't be imported and returns this error: ERROR: Geometry type (Polygon) does not match column type ...
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2answers
4k 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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2answers
423 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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2answers
2k views

Import large CSV file into PostGIS

I am trying to import CSV files into PostGIS. Following this post, I have created tables before. I found other suggestions saying that I can run the copy command. If I run this command: COPY table ...
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2answers
2k views

GeoServer: Shapefile or PostGIS?

I'm going to build a web application, which will render around ten maps using GeoServer. I will be also changing the attribute data in the application for some layers. So, what is the recommended ...
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2answers
400 views

Clarification of the “25D” option in ogr2ogr

[EDIT: In my original post, I had received an error that was based on a typo, so I scrapped that part of the question, but left the questions that still apply.] In the ogr2ogr docs it says: -nlt ...
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1answer
949 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
88 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 ...
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1answer
723 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
399 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 ...
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4answers
4k 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 ...
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1answer
427 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 ...
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2answers
3k 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?. Thanks!
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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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1k views

Raster data on PostGIS

I need to publish raster and vector data through GeoServer WMS service and I have already chosen PostGIS as datasource to keep vector data. Now I would like to know what is the best practice to work ...
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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 ...
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1answer
383 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 ...
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1answer
715 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 ...
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1answer
210 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
106 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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2answers
530 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 ...
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3answers
618 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 ...
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1answer
241 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 ...
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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 ...
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1answer
385 views

Self-intersecting polygon using extreme values

I have this polygon POLYGON((1.2E-15 1.1E-15,1.31E-15 1.21E-15,-180 -90,180 90,1.2E-15 1.1E-15)) It uses an extreme coordinates like (1.2E-15 1.1E-15) and (180 90) When I call ST_isValidReason, ...
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1answer
2k views

Performing Geoprocessing SQL Queries in QGIS from a PostGIS Database

This may be a dumb question, but is there way to run a PostGIS geoprocessing SQL query in QGIS? Specifically, I am thinking of running SQLs such as ST_Union, ST_Split etc etc. I have tried the ...
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2answers
790 views

Indian Latitude Longitude values

I am in need of around 10000 and odd Indian latitude and longitude values for my openlayers project. I have to load them in a postgis db. so a sql file or atleast text file would be better than a ...
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1answer
85 views

Create common vertexes between shared polygon boundaries in PostGis?

Given two polygon tables L1 (blue) and L2 (red) that share a common boundary but different amount of vertexes, how can one make the shared boundary identical (they should share the same vertexes) ? ...
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1answer
112 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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2answers
100 views

Which one of these azimuth values is the right one? And why?

First of all, let's make clear that I want the Azimuth on the surface of the Earth, i.e. the angle between two locations, for example New York and Moscow. I am testing some azimuth calculations with ...
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2answers
389 views

ESRI projection to SRID?

I am looking at MapX and MapY coordinates. The docs say they are "truncated State Plane coordinates: NAD 1983 State Plane Louisiana South FIPS 1702 (US Feet)." I am trying to reproject into a common ...