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

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Extract city boundary from TIGER data

I'm trying to find the bounding box of US cities but I just can't seem to figure out what to do with the TIGER data I download (not to mention, which data to download!). Could someone experienced with ...
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197 views

Traversing all possible road routes

I have created a topology from OSM data and would like to simulate a car driving every possible route along the map. The purpose is to "survey" the osm data as if in a car. My ultimate objective is to ...
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1k views

PostGIS intersection function

I have a problem with intersection function. I built my query following http://manual.linfiniti.com/en/postgis/geometry.html, 5.7 section. I made my clip object, a red linestring frame: But after ...
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513 views

Error: Coordinate values are out of range [-180 -90, 180 90] for GEOGRAHY type on Postgis?

when I run a query on Postgis select st_astext(ST_SetSRID(f.geom,4326) ),st_astext(st_centroid(ST_Transform(b.wkb_geometry,4326))) from a,b where ST_Distance_Sphere( ...
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120 views

How to get intersected points between polygon and line in desired order

I have polygon for example "POLYGON((5 1, 6 1, 6 5, 5 5, 5 1))" that I want to intersect with line "LINESTRING(0 2, 10 2, 10 3, 0 3, 0 4, 10 4)" and get intersection points in the order that they ...
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2answers
4k views

PostgreSQL function does not exist

I have PostgreSQL 9.2 with Pgrouting extension, but when I want to call a function(pgrouting) does not work. Id like to compute the shortest path between two point. SELECT gid, AsText(the_geom) AS ...
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1answer
838 views

pgrouting php problem “pg_fetch_result(): Unable to jump to row 0 on PostgreSQL result index 3”

I'm trying to build a simple routing web-app using pgrouting, followed some tutorial and the latest workshop. Because I'm using PostgreSQL 9.3(x64), Postgis 2.1.1, and pgrouting 2.0 so I did some ...
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3answers
2k views

How to import shp2pgsql on mac?

I am using EnterpriseDB to run Postgis. when I run "shp2pgsql" on got an error message. ~ macbook$ shp2pgsql -bash: shp2pgsql: command not found ~ macbook$ which shp2pgsql I read that I should ...
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69 views

PostGIS layer attribute table empty in Quantum 2.0.1

I recently installed QGIS 2.0.1 (Dufour) on a Windows 7 PC (64-bit). Today I tried, for the first time since Dufour was installed, to load PostGIS layers into QGIS. I successfully set up a connection ...
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127 views

How to force dropping a table/Index

I was working to import CSV Files into PostGres. CREATE TABLE NY(Name varchar,Latitude float,Longitude float); COPY NY FROM 'data/NY.csv' DELIMITERS ',' CSV; ALTER TABLE NY ADD COLUMN gid serial ...
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1answer
302 views

Spatial Join in CartoDB

I need to update a table of points with the FIP code of the nearest county polygon from a separate table. I've managed to update the column for those points that Intersect a county polygon with this: ...
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720 views

Draw postgis geometries in google maps api

Postgis have a base with a table of data lines and other points. I'm doing a java applet to query these tables and space to draw on google maps. My question is: what better way to spend these ...
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676 views

Finding the Closest Points using ST_ClosestPoint() for MULTIPOLYGON

I am working to match between the closest points of two tables. I have two tables: Building, SchoolBuilding. Building Table: Contains Polygones, SchoolBuilding Table: contains Points (From ...
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1answer
443 views

Transferring data between spatial databases

I would like transfer spatial data from PostGIS to Oracle Spatial. I want to use Python's modules psycopg2 and cx_oracle. Transfer Oracle > PostGIS is OK, but in opposite version I have problem with a ...
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1answer
304 views

how to snap two line vertex in two different layers used in QGIS

I want to snap between two poly-lines from 2 different layers (Layer1 in Brown and Layer 2(postGIS layer) in Pink color- ), but my snap option don't work. I have changed the tolerance to different ...
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1k views

Indoor mapping with floor plans and item(s) to track

Warning: GIS noob here. Essentially I want to be able to create a floor plan for a given room. Consider the following image of a floor plan in image format: I would have the measurements of every ...
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3answers
163 views

What is the PostGIS 2.x equivalent of the pre-PostGIS 1.5 ~= operator?

Stemming from my other question: When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?, what is the PostGIS 2.x equivalent of the pre-PostGIS 1.5 ~= operator? It ...
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2answers
242 views

Import CSV file into Postgis DB with Location-field formatting?

I am working to import CSV into table in my Postgis Database. First, I created the table Create Table test ( name varchar, created_date Date, location double precision ); When I excuted the ...
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4answers
159 views

Best way to 'join' polygons

I'm looking for the best ways to 'group' a budge of block polygons in a new polygon that should be the town. My block layer is something like this: Or zoomed: And I'm looking to get something ...
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5answers
1k views

Problem installing PostGIS on Ubuntu Server 13.10

I've installed PostgreSQL 9.1 and postgis on Ubuntu Server 13.10 as follows: sudo add-apt-repository-ppa:ubuntugis/ubuntugis-unstable apt-get update apt-get install postgresql-9.1-postgis then I ...
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1answer
288 views

When would a PostGIS geometry compare using ~= return true when ST_Equals returns false?

I have a couple of featureclasses in a 10.2 geodatabase/PostgreSQL 9.2.2 database and I've been struggling with the FeatureCompare tool--it is telling me geometries are different on some features ...
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1answer
62 views

Is there a way to use some sort of “instancing” when storing polygons in a spatial database?

I am quite new to GIS database addons, and I am still exploring the possible uses for them. In general the idea of storing objects indexed by their position which enables additional operations is ...
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2answers
141 views

Measure areas, lenghts in specific regions (Australia, Sout East Asia)

I'm in need to find a suitable projections to measure correctly areas and lenghts for 2 areas of interest. I want to measure both factors for: 1) First region Australia & New Zealand (1st ...
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492 views

Calculating difference between bearing values in degrees

Suppose I have 3 geographic points, A, B and C. I can calculate the bearing of B from A (in degrees) using this SQL snippet: degrees(ST_Azimuth(geogA,geogB)) as brg_a_b ...and the same of C from ...
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1answer
321 views

Does ora2pg support the SDO_GEOMETRY spatial type?

I've been searching the net up and down for days now and can't find a definite answer to this question, neither on google nor on the official page (http://ora2pg.darold.net/). Does ora2pg support ...
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3answers
449 views

How ensure data put into PostGIS gets proper CRS attached?

I recently had an intractable problem that we finally traced back to the fact that some points in a PostGIS table had a CRS associated with them and others did not. This resulted in some points being ...
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1answer
211 views

Interpretation of PostGIS geocode function ratings

Edit: I am using Postgres 9.2 and recently installed PostGIS along with the Tiger Geocoder from the extras folder and downloaded all the latest Tiger data. I have been testing the Tiger Geocoder ...
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2answers
1k views

SQL Syntax to extract (convert) Strings with Degrees Minutes to Decimal Degrees

I have a PostgreSQL/PostGIS database with a two string fields containing Lat and Long coordinates in degrees and decimal minutes, like this 45° 24.5' N 3° 43.01' E. How can I convert them into ...
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4answers
252 views

Linking up GPS points taken from rail network

Bit of a newbie here, trying to work out whether any PostGIS functions can help with my task. Apologies in advance if my use of GIS terminology is not up to scratch yet. I have a large database of ...
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1answer
3k views

Publishing OSM data in GeoServer that has been imported into PostGIS

I'm trying to publish data on GeoServer. I'm using Postgres/PostGIS and I've used osm2pgsql to load the data into the database. I've configured a store correctly (I can see the tables from the ...
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2answers
2k views

What is this PostGIS query doing to show great circle connections?

I'm trying to draw a flight map in CartoDB. My starting point is a single lat long point. We'll pretend it is this: ST_GeomFromText('POINT(-71.060316 48.432044)', 4326) And I want draw lines ...
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1answer
594 views

Spatial database containing coordinates for stars in the sky?

My goal is to map the Skydome ( stars in the sky projected in earth surface ) using GIS. Has anyone done this before? I can't find any project close to this. What I just need to know is if there is ...
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2answers
965 views

Architecture for java ee application

I´m new to GIS development. I have read about Openlayers, maps servers (i choose Geoserver), geodatabase (in my case i choose PostGis) and theory of gis in general. I´m developing a Java EE ...
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184 views

Scaling CartoDB to multiple machines

I'm interested to scale CartoDB installation to multiple machines to distribute computational resources. We start using torque with some big tables (more than 5 to 10M points) and the processing for ...
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2answers
423 views

Postgis 2.0 simplifying multipolygon

I have a data set of national boundaries for the African continent. These are in a multipolygon table in postgis. Each country has multiple entries (rows) such that some of the countries in my table ...
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1answer
523 views

Mapnik render Error : Could not create datasource for type 'postgis'

I try to use mapnik render for a tile server. During the initialization 'renderd -f -c /usr/local/etc/renderd.conf', the following error message is displayed : An error occurred while loading the map ...
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1answer
2k views

Copy a spatial table from one PostGIS database to another PostGIS database

I have two PostGIS databases on two different servers. The first server is PostGIS 2.0 and the second server is PostGIS 1.5. On the PostGIS 2.0 I have a table "lakes" with MULTIPOLYGON geometry ...
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1answer
345 views

Computing radius of gyration in PostGIS

The radius of gyration is a measure of the standard deviation of distances between points (and their center of mass), i.e., how frequently and how far points are moving. A formal definition is: I ...
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159 views

Why CQL DWITHIN returns different result than PostGIS DWITHIN?

I have 2 tables in PostGIS that I publish to geoserver. both have same SRS (2039). When I do the following query in PostGIS , I get 69 results : SELECT a.gid,b.gid FROM Table_A a INNER JOIN ...
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2answers
844 views

How can I add a PostGIS query result to OpenLayers?

I'm doing a query on PostGIS that returns a lot of geoemtries as results (more than 1000 which is why I can't use Geoserver CQL) - the query WHERE CLAUSE is being changed each time by the user (its ...
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2answers
747 views

How to calculate area or centroid of the_geom in CartoDB?

Is it possible to calculate area or centroid of the_geom in cartoDB? It would not be a huge time saver, and I am doubtful that it is an option but figured I would ask.
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2answers
1k views

Select points from a table that exist in a custom polygon

We have a property search site where the user draws a polygon on a map and then the app displays all properties that fall within the polygon. We have properties stored within a Postgres table that ...
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1answer
173 views

pgRouting and Openlayers error when insert controls variable

I've got another problem here :( I'm following the foss4g_w12 tutorial for building a pgRouting WebApp using openlayers, everything goes well until I added the following statement to my code: ...
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2answers
865 views

How to check if points are within a circular sector using PostGIS?

I want to get the stars within the black region as shown above. To find this I have the centre of circle (lat, long), radius and the angle of region (45 degree). I am new to postgres. I worked on ...
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1answer
894 views

Why does reading shapefile from PostgreSQL database give Error reading OID from table …?

I'm using arcgis 10.1 and i have a connection to a PostgreSQL 9.3 database. When i try to load a shapefile using the add query layer I get an error when opening the attribute table. The error says ...
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1answer
747 views

OpenLayers + GeoServer's WMS — Passing Feature ID into a Variable

I have a WMS PostGIS-based polygon layer served by GeoServer, and whenever I click on any feature I want to get its gid value, so I can pass this value to the DOM. Unfortunately, I could not find a ...
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1answer
709 views

Is there a way to use OSRM with PostGIS

Is there a way to use OSRM with PostGIS (Windows)? Related: Why mobile routing is so fast?
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3answers
804 views

How can I obtain the same area values provided by the Census for TIGER boundaries using PostGIS functions?

In PostGIS, how can I compute the area of Census Boundaries and obtain the same results as are provided by the Census? For example, most Census Boundaries include attributes for Land Area and Water ...
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1answer
283 views

How to provide a WFS in multiple projections

I would like to set-up an editable web feature service (WFS-T) for serving my geospatial data. The data tables are in a PostGIS database on the same server. For security reasons my server admin ...
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1answer
114 views

PostGIS: How to understand ST_RasterToWorldCoord() right? (PostGIS 2.0)

After putting raster in to postGIS by this Thank @Sorin for helping me out! Now, I want to output raster tile, then view it on QGIS. But the problem is the output of ST_RasterToWorldCoord(raster ...