Version 2.0 of PostGIS brought a heavy set of new extensions for the PostgreSQL object-relational database, adding greater support for spatial objects.

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9
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1answer
194 views

What PostGIS [topology] provided tools may be used for data quality assurance?

I'm learning about techniques to ensure GIS data quality. Googling around, I've found a few papers about theory and best practices (here and here), and a couple of short presentations about the topic ...
1
vote
1answer
80 views

How do I project a point stored as Lat / Lon to a state system?

I have some points stored as WGS84 (EPSG:4326) data. I want to write a SELECT statement to return the projected values, in EPSG:2811, and unprojected values. Here is my table SQL: CREATE TABLE ...
1
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0answers
72 views

Postgis - st_MakeLine and st_lineLocatePoint

Lets explain, I have 4 points (1,2,3,4), and I need to visit clients (A, B, C, D). So, I need to use st_makeline with (1,2,3,4,3)... Now I have to get % position from A,B,C,D; but in visit order. ...
1
vote
1answer
724 views

Unable to create Polygon using Geodjango admin interface

I am new to GeoDjango. I have created Admin interface for my Model. It loads correctly. I am also able to draw the Polygon on map(At client side) but when I save It tells me Invalid input and throws ...
0
votes
1answer
33 views

problem in PostGIS Name of the system used for Points and how to get distance between to point?

I have started to work on a project in PostGIS. I have a table with a geometry points in which points saved like this : "010100000089F511C671C01E4162327E2A83545341" and I have translated this ...
0
votes
2answers
162 views

Neighbors within distance from every row

I have a research project of 180,000 entries and I need to calculate the number of neighbors (points from the same table) that exist within a 300 meter radius for each point. My method is very slow, ...
0
votes
1answer
139 views

OpenLayers WFS-T tinyows insert transaction: error GID value

I try to implement insertion of new point using Openlayers v2.13 saveStrategy calling tinyows which implements the WFS-T transaction; I use the example from http://mapserver.org/tinyows/...
1
vote
1answer
179 views

How to create Spatial Reference System in QGIS?

I have some Attribute and the coordinate and the coordinate reference system. I want to create a DBmanagamet form my spatial data. To do that I want to create one table with name Spa_ref_sys, but I ...
1
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0answers
89 views

Problem with ST_SummaryStats, ST_Buffer, and casting between geometry/geography types

I have a test raster that covers the world ((-180 90), (180 -90)). The SRID is WGS 84 (EPSG:4326). Values for cells in the north-western quadrant ((-180 90), (0 0)) are random integers in the range 1 ...
2
votes
2answers
263 views

How to get the number of polygons of a geometry in PostgreSQL

How can I get the number of polygons that form a geometry in PostgreSQL? For example U.S map has a lot of islands in addition to its main lands. I want to count these islands plus the main lands.
7
votes
3answers
5k views

Loading geotiffs into PostGIS using raster2pgsql

I have an issue with loading some Ordnance Survey raster data into PostGIS. I have been using the following raster2pgsql command to load a tif that I have placed in my C:\Program Files\PostgreSQL\9.1\...
1
vote
1answer
110 views

Incorrect lat / lon conversion from utm

I used this website to determine that the SRID for my shapefile is 3857. Following that information, I used the shp2pgsql utility to convert my shapefile into the sql I need to insert into PostreSQL (...
0
votes
2answers
198 views

Find closest points in routing network for a set of points to pick shortest route

I have the following WITH SQL Query which does select a set of filling stations along a route within the distance of 1000m. In the SQL statement I fetch 1 Point from the station and search the closest ...
1
vote
1answer
331 views

How to detect gaps in a MultiPolygon table with Postgis?

I have mapping of land use. In it, I need running topology to detect gaps between polygons. Is there postgis's function to do this? Thanks
1
vote
0answers
97 views

Automatically generate random polygons with a given number of vertices

Updated to make it clear. What would be the fastest way to generate a random polygon in PostGIS with a specific number of vertices? I want to create a PostGIS function like GeneratePolygon(1000, ...
1
vote
1answer
61 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 ...
1
vote
0answers
140 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 ...
11
votes
2answers
8k 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 ...
7
votes
4answers
3k views

What does the “service” box in the PostGIS connection dialog stand for?

Can sоmеbody explain me what to write in the "service" box when connecting to the local DB. QGIS Lisboa and Postgres are installed.
3
votes
1answer
356 views

How to import a GeoTIFF into PostGIS without raster2pgsql

I know that one can import GeoTIFF into PostGIS via raster2pgsql. I was wondering if there is any easy way (as a sequence of SQL statements) to do the same without resorting to the command line tool? ...
1
vote
3answers
267 views

Convert SRText To PROJ4TEXT

I'd like to convert the following for updating my spatial_ref_sys table. PROJCS["USA_Contiguous_Albers_Equal_Area_Conic_USGS_version",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",...
3
votes
1answer
114 views

PostGIS strange difference in distance calc from different point defenitions

I have a working POSTGIS database, loaded Dutch CBS data using shp2pgsql and now I want to map lat,lon coordinates to multipolygons. All examples I see use lon lat coordinates but if I do so I get ...
1
vote
1answer
170 views

What do pixeltypes in PostGIS raster mean?

I'm trying to build a raster in PostGIS from a vector layer and I was curious as to the meaning of pixeltypes in the raster geometry? How does it effect my raster?
2
votes
0answers
253 views

pgrouting librouting.dll library is supposedly missing when it is not

Yesterday, I successfully installed pgrouting from the most recent x64 2.0.0 binaries, at least this is what I thought. I was able to perform first query - select pgr_createTopology() from the ...
0
votes
1answer
160 views

Open Source GIS Problem [closed]

I am new at open source GIS platform. I am using Ubuntu 12.10. I have tried to install the followings but without 2-3 tools I could not install anyone. Can any body help me how can I install the ...
1
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2answers
752 views

Python Geoserver gsconfig create resource from Postgis store table

I've working Workspace and PostGIS store in GeoServer. I would like to use python and gsconfig to create new resource/new layer from existing PostGIS table, with: computing bbox, adding abstract, ...
5
votes
1answer
388 views

Postgis Difference with Geometry union

I've got two GIS tables, let say A and B. I would like to do the difference of A using B. While it's pretty straightforward to do it with QGIS (using geoprocessing->difference), I've got much more ...
2
votes
1answer
267 views

PostGIS replace pixel value by lookup table?

I was wondering if it is possible to write a PostgreSQL statement to replace the value of each pixel in an input PostGIS-raster with a value obtained from a look up table. For example, suppose I have ...
1
vote
2answers
501 views

How to get the closest point from a table in PostGIS?

I have a table of pgrouting nodes, structured like this: CREATE TABLE ways_vertices_pgr ( id bigserial NOT NULL, cnt integer, chk integer, ein integer, eout integer, the_geom geometry(...
10
votes
2answers
1k views

What is the precision of SELECT DISTINCT on PostGIS geometry column?

I wonder what the precision of the SELECT DISTINCT operator is on a PostGIS geometry. On my system, the following query gives me a count of 5, which means that the inserted points are considered equal ...
3
votes
1answer
219 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 ...
0
votes
1answer
643 views

Why is result of ST_Area or ST_Distance in SRID 4326 so small

there is one thing I do not understand when using the following Query in geometries which are all SRID 4326. WITH s AS (SELECT * FROM de_sim_points_start WHERE id = 6545) SELECT e.*, ST_Distance(e....
1
vote
1answer
56 views

Is product purchaser in distribution area?

I am going to be using PostGIS 2 to create a lookup service. Given a point (lat/lon), I need to either find if a product can be distributed there, or b) a list of products or distributors. I am ...
2
votes
0answers
161 views

What is causing invalid spatial reference error using ogr2ogr converting PostGIS to FileGDB in a Feature Dataset?

I am trying to use ogr2ogr to convert a layer from PostGIS to a FileGDB. I want the layer to be created inside a Feature Dataset. The spatial reference of the source layer is EPSG:3500. The spatial ...
1
vote
1answer
22 views

Original Size from Tiled PostGIS Raster

Does anybody know of a quick and easy get the original height and width (rows and columns) of a tiled raster in PostGIS? Using a combination of items I know this can be calculated so just wondering ...
3
votes
1answer
700 views

Postgis is Broken after installing Nominatim

I followed Nominatim Tutorial to install PostGIS and after that I can't access PostGIS at all I already trying reinstalling and installing everything over and over again with no success. Everytime I ...
1
vote
1answer
112 views

importing shapefiles to postGIS on QGIS1.8

I am trying to import a shapefile into postgis from within QGIS 1.8. The QGIS is based on a server that is not managed by myself. I have requested an upgrade to QGIS 2.0 ...but this may take ...
2
votes
2answers
86 views

PostGIS 2.0 and Self Intersecting Features

I have a polygon feature class created by open streetmap that is returning a self intersection error. Is there a way to filter out these feature? Can I just use a sql statement to find the error ...
3
votes
2answers
5k views

How to find nearest line from point using PostGIS?

I have a table of Roads in PostGIS which geometry is "geometry(MultiLineString,4326)". Its attribute are gid osm_id name ref type oneway bridge maxspeed geom Now i want to know ...
4
votes
1answer
1k views

PostGIS: Merge multiple table with same GID

I just imported some shapefiles with the PostGIS importer. Because several errors and issues I had to split my shapefile in multiple parts. Then I imported them one by one. I thought I can easily ...
1
vote
1answer
638 views

How to have PostGIS 2.1 and the Python osgeo library installed together without compiling from source?

My python application makes heavy use of the osgeo library. We're looking to upgrade from PostGIS 1.5 to PostGIS 2.1, and I'm having issues. I'm installing packages from the Ubuntu GIS PPA. Before, ...
3
votes
0answers
51 views

Loading raster data into postgis database

i would like to add raster data to my postgis database. when i try to check if postGIS is responding to requests using the following command psql -c "SELECT PostGIS_Version()" ,i get an error message ...
0
votes
0answers
223 views

Importing a Raster into PostGIS 2.1 (Windows 7)

I am trying to learn how to import rasters into PostGIS (2.1). I have read through all the material I can find on doing this and know that the recommended tool for this is the raster2pgsql tool. I ...
2
votes
2answers
285 views

How to update PostGIS 2.1 to use `ST_DelaunayTriangles()`

The error "lwgeom_delaunay_triangulation: GEOS 3.4 or higher required" arrives on my terminal, running psql with SELECT PostGIS_Lib_Version(); -- 2.1.4 SELECT postgis_version(); -- 2.1 USE_GEOS=1 ...
0
votes
2answers
1k views

ST_Touches for more than just one geometry

I'd like to select some neighbor polygons with ST_Touches. Therefore I found the following statement: SELECT b.name FROM layera as a JOIN layera as b ON ST_Touches((SELECT a.geom FROM layera as a ...
3
votes
1answer
266 views

How to populate geography point using ST_MakePoint(long, lat)

I have a table called customer_campaign, and there is an empty column geom(geography) in it. So I want to fill it up by using ST_MakePoint(long, lat) in PostGIS, lat and long are two columns in the ...
0
votes
1answer
45 views

Is PostGIS-2.x raster in text format (WKT) only?

I was reading PostGIS FAQ and this tutorial. From all that I can tell, it seems that PostGIS raster is a text format, i.e. WKT or well-known-text. I was wondering if PostGIS raster data are text-...
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0answers
63 views

Does qgis support postgresql range types?

I added a postgis layer with date range column in Qgis but that field is not listed in Qgis.
2
votes
1answer
72 views

How to make my PostGIS vector layer in QGIS visible?

I have loaded a shp file (simple polygon with one entry) into PostgreSQL 9.3 (with extention PostGIS v2.1.3). I now want to load this layer into QGIS (v2.2.0 Valmeira) via the "load Postgis layer) ...
1
vote
1answer
125 views

Only my geometry layers are exported from spatialite to postgis

I have a spatialite database (v4.1.1 / SQlite v3.7.17) consisting of one geometry table and several attribute tables linked to the geometry table by foreign keys. I want to export all tables to a ...