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

learn more… | top users | synonyms

0
votes
2answers
44 views

Split lines into non-overlapping subsets based on points

Given a table with line geometry, and one or more points that are snapped to this line in a separate table, I would like to split each line with one or more intersecting points at each of the ...
0
votes
2answers
208 views

Create multi-line from point in PostGIS

I'm working on an old table where polygons are stored as points. Now, I want to migrate these points to PostGIS and store them as polygons (or multi-polygons). The table structure is as follows: ...
6
votes
1answer
190 views

Where can I find PostGIS error codes?

Using ST_Contains in where clause sometimes gives me error messages like ERROR: GEOSContains: TopologyException: side location conflict at 37.3706 55.7882 For now I can't guarantee validity for ...
1
vote
2answers
90 views

invalid KML representation on ST_GeomFromKML

I exported a table with a geography(MultiPolygon,4326) column using ogr2ogr to a KML file. When trying to re-import any of the shapes using the ST_GeomFromKML function I get the following error: ...
1
vote
2answers
319 views

Polygon intersection with bounding box with polygon's holes intact

I am trying to serve GeoJSON FeatureCollection tiles with each feature's geometries trimmed to the tile boundary. I am working on a Leaflet plugin to re-assemble the geometries. It works by building ...
0
votes
1answer
83 views

Create shp file from data postgis / kml using java

I'm working on a geographic information system project, whose products form shp file. I am using java language, and PostGIS database. Is there a way to generate a shp file from PostGIS or kml using ...
2
votes
1answer
383 views

A software architecture for viewing/editing roads and routes

I have a routing software module which uses PostGIS/pgRouting to calculate routes. The road network is generated from an .osm file with osm2pgrouting tool. I need to enhance the functionality of the ...
3
votes
1answer
46 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 ...
1
vote
1answer
47 views

Is the Azimuth on the equator equal to the one not on the equator?

I am trying to fully understand the concept of Azimuth and I am encountering some inconsistencies (or maybe it is my error). I show you some examples that do not match, hoping somebody can explain me ...
1
vote
2answers
2k views

Exporting shapefile to PostGIS database in QGIS

How do I export a vector shapefile to PostGIS database? I am asking what format I have to export it.
3
votes
1answer
91 views

Postgis 2.0 geographic polygon has max longitudinal range

My problem is that I have a load of geographic point data (srid 4326) in a table. A user may do a bounding box search - essentially create a polygon as follows: l_poly geography(Polygon,4326):= ...
2
votes
1answer
146 views

CartoDB “Error loading rows, check your SQL query” & “There is a pb with your connection”

I have been trying to install my own CartoDB server for a few weeks. I succeeded to install each part with no error (after few corrections) with this tutorial. Make check with CartoDB-SQL-API and ...
3
votes
1answer
235 views

Problem PostGIS Spatial Query ST_Contains ST_Disjoint ST_Intersects

I'm working on a project with two different tables inside a database. One contains points in a column geometry(Point,4326) type and the second one has a column geometry(MultiPolygon,4326). Now I would ...
0
votes
1answer
137 views

ArcMap reports that PostGIS polygon data is self-interescting

I have an ESRI File Geodatabase of data that I upload to PostGIS using FME. Seeing as I have to have the data in PostGIS for other purposes, it would be great to view the data in ArcMap straight from ...
2
votes
1answer
25 views

PROJ4 / PostGIS transformations between WGS84 and NAD83 transformations in Alaska

I'm trying to implement the recommended WGS84 - NAD83 transformation for Alaska using PostGIS. This post: Geographic Transformations in Alaska Between NAD83 and WGS84 indicates the proper ...
14
votes
1answer
346 views

How to query OSM for all beaches facing west? - QGIS preferred

I want to identify all beaches on this planet (or a given subset of it) that are facing westwards (+/- 20-30 degrees). My idea is to use OSM as the data source. Extracting all polygons that have the ...
1
vote
3answers
46 views

postgresql export database with command or pgAdmin III

I want to export my postgresql db with pgadmin. I search all of its GUI, I also searched the web and I don't find some sueful information. I know how to import the db into postgresql: create a db with ...
0
votes
1answer
90 views

Import DEM into PostGIS for QGIS

I'm a complete GIS newbie so sorry if I'm using the wrong terminology in searching for a solution to this... I'm trying to import a DEM into PostGIS and display it in QGIS. The data is from the EU-DEM ...
2
votes
1answer
44 views

SQL query to have a complete geojson feature from PostGIS

I would like to get a geojson feature with properties from PostGIS. I have found an example to have a feature collection but I can't make it works for just a feature. so far I tryed to modify the ...
1
vote
1answer
83 views

Geoserver OSM data Imported via osm2pgsql - most efficient tables to use to style roads

The Osm2pgsql importer for OSM data to Postgres results in two tables for ways, one called planet_osm_roads and a second one called planet_osm_lines The Osm2pgsql documentation states that the ...
1
vote
1answer
24 views

function ST_Line_Interpolate_Point with multilinestring

Is there a function like ST_Line_Interpolate_Point but using a multilinestring?
0
votes
3answers
116 views

Import shapefiles on my postgis table using R

Using R, I would like to import shapefiles that are in a directory on a geometric table i have on postgresql / postgis. What is the instruction that allows me to do it? EDIT: here is my code to ...
7
votes
1answer
620 views

Is it possible to geocode street intersections using Nominatim?

Is it possible to geocode the location of a street intersection using Nominatim? Example geocode query Commonwealth Ave at Washington Street, Boston, MA Successful Geocode by Google ...
2
votes
1answer
561 views

Problem in importing raster data from PostGIS to Geoserver

I am using Opengeo Suite 3.0.2, PostGIS 2.0.3 and PostgreSQl 9.2. I am trying to import raster data from PostGIS to Geoserver but facing an error. I follow this tutorial link to import the raster ...
1
vote
0answers
18 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', ...
3
votes
2answers
53 views

Buffer multiple roads to find points within and compare?

What I am trying to do is buffer a main st and a side street and get all of the points that intersect that buffer, however they need to be mutually exclusive. In the example below, my results would ...
3
votes
2answers
5k views

How to install PostgreSQL 9.2 with PostGIS 2.0 on Ubuntu 11.10 (or higher)?

I have read this question: Install PostGIS v2 for PostgreSQL v9.2, but it didn't resolve my problem. I added the PostgreSQL backports PPA and installed the postgresql-9.2 package, but there is no ...
0
votes
0answers
33 views

How to calculate the Azimuth between two points in PostGIS?

I have a GIS API based on OpenLayers. I have been trying to implement Azimuth calculation in JavaScript and I needed some way to calculate the Azimuth in order to perform tests. I started using ...
0
votes
1answer
14 views

Road displays up to node, not up to starting point and ending point

SELECT id FROM table ORDER BY st_distance(the_geom, st_setsrid(st_makepoint($slng,$slat), 4326)) limit 1 ; get source and similar for target ; and then apply in dijkstra algo SELECT pgr_a('SELECT id ...
4
votes
1answer
1k views

Union, Dissolve, Buffer — multiple layers, all in one step?

I'm a new user of Quantum GIS (1.7.3) and I need to repeat a task multiple times, so I'm wondering if there is a quicker way to do the following (with three or more polygon layers - each layer has a ...
1
vote
1answer
42 views

Is there a PostGIS function to get a tangent and normal line?

I'm looking for a function that will return a tangent (and normal) for a LINESTRING in PostGIS. I think this is the 3rd time I've come across the need for this function and everytime, I end porting ...
5
votes
2answers
51 views

Working with address data extracted from *.osm

My goal is get all the addresses from a certain country, ideally - from all countries, but for now - only from one. I downloaded an *.osm file from here http://download.geofabrik.de/ for a certain ...
2
votes
0answers
27 views

Determine PostGIS geography polygon orientation

How can you determine the orientation of a PostGIS geography polygon? I'm looking/hoping for a function that would tell me which side is the interior (left or right) as you traverse the vertices of ...
0
votes
0answers
11 views

Working with different source WMS data

I have a geoserver and WMS services on it. For example my water valve layer is point data and published from geoserver. (I am using postgis to saving data.) An external WMS service publishes polygon ...
1
vote
0answers
22 views

Query PostGIS database without creating primary key [closed]

I'm trying to query PostGIS database from QGIS DB Manager: select row_number() OVER(ORDER BY idx DESC) as id, p.*, * from table_1 join table_2 as p on "name" = "name" where row_number() OVER(ORDER ...
1
vote
0answers
37 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 ...
3
votes
0answers
46 views

PostGIS - Interpolate point between contours

Using PostGIS, what is the best method to interpolate the z value for points (the orange dot in the image below) located between each contour layer (blue lines and red lines in the image below)? So ...
2
votes
1answer
38 views

<#> doesn't give a useful distance

I'm new to postgresql/postgis and trying to measure a distance. So st_distance() may be the most accurate, it's the slowest too (as I've read). I read that one can use geometric (instead of ...
3
votes
1answer
42 views

Find the closest line vertex from the linestring using PostGIS

How to find the closest line vertex from a linestring? ST_ClosestPoint will give a point which is not from the linestring.
8
votes
1answer
1k views

One to Many Relationship in QGIS with PostGIS

Does anyone know of any tool that can do a One-to-Many relationship in QGIS. I have my data in a PostGIS database. I would like to be able to query spatial layers that are related to spatial or non ...
6
votes
2answers
168 views

How to sample a 3D raster along a 3D path (or 4D raster along 4D path)?

I have a 3d raster dataset of atmospheric variables (lat x lon x altitude). I would like to sample this raster dataset along a 3d path. Any idea how I can achieve this, preferable with qgis or ...
1
vote
1answer
50 views

How to easily remove loose/isolated edges from pgRouting network?

I wondered if there's an easy way to 'clean up' a pgRouting network by removing those edges that do not connect with the global network. Otherwise you risk to end up with cost values of -1, meaning ...
1
vote
2answers
53 views

select intersection of 2 geometries, polygon and polyline

I'm searching how to have a result of 2 geometries (villages and wetland) which don't intersect. When I write: select distinct v.name from villages v , wetland w where ST_intersects(w.geom,v.geom) ...
1
vote
0answers
21 views

Postgis / QGIS Snap Point to Line

I'm trying to snap points to lines in postgis for use in QGIS, but cannot get it to work. I have one line in my line table (although it was created by merging multiple lines together) and about 600 ...
1
vote
0answers
36 views

PostGIS - Intersects feature to split into linestring

I would like to know if it's possible to intersect feature datasets (multipolygon, polygon, multilinestring and linestring) to get a result as a set of linestrings being split at each intersection ...
7
votes
2answers
3k views

What is the best way to do reverse geocoding with PostGIS?

Is there a way to do reverse geocoding with PostGIS? There's a lot of information on the Web but I found it very confusing... I have imported osm data into my own Postgres with PostGIS database. Now ...
1
vote
1answer
13 views

postgis - managing single dataset, multiple coordinate systems

I am setting up a forest inventory database that aims to store information about forest plot data from various countries. The current project is in Mozambique, others are in Laos, etc. Each project ...
5
votes
1answer
403 views

Generating Interactive Tiles using Nodejs, Mapnik, and PostGIS for Leaflet

I am looking to do something like this but where I have all the data on the same server. I've been following through the set of tutorials @ sparkgeo.com/labs/big/ and I'm having some difficulty. ...
3
votes
1answer
101 views

Routing problem finding shortest route to line

inspiration on how to solve this problem. (Ascii art, I don't have points to insert picture) I need to find Z Z = Shortest route from X Using Road (no point exists here) O = The points that makes ...
3
votes
1answer
31 views

PostGIS ST_ConvexHull for cube corners not as expected

I'm new to PostGIS and am wondering whether ST_ConvexHull will be of use in a particular work problem. Trying out some simple cases to make sure I understand what it's doing, I didn't expect this: ...