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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2answers
2k views

Geoserver Routing with OSM data and PostGIS

Does Geoserver have a routing functionality for the OSM data in PostGIS?
4
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2answers
525 views

Data entry and manipulation using web pages

I am working on a project where we want to move a database from Microsoft Access to PostGIS, and we want the data entry forms to be web page based rather than forms within the Access database. I am ...
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4answers
10k views

How to get the nearest point on a linestring to a given point?

I've been using PostGIS for a long time now but never had to use the LINESTRING geometry ...! :) Here's what I would like to do : I have a table of linestrings (representing streets of a given city, ...
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2answers
1k views

I want to edit corresponding postgresql data of a vector from openlayers- how to do it?

I want to edit the corresponding text/numeric data type columns of a vector through openlayres, when a user click/mouse over a vector. like, http://dev4.mapgears.com/bdga/bdgaWFS-T.html# any ...
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3answers
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Render vectors from OSM data in POSTGIS database

I'm a newbie when it comes to mapping application. I had successfully loaded my OpenstreetMap data in a Postgresql/PostGIS database. Now my problem is how to render the vector data (the POI's, ways, ...
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5answers
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Problems in installation of PostGIS

I will be installing PostGIS for my project using PostgreSQl (OSM) in Ubuntu 9.04. I had all the requirements prior to the installation (PostgreSQL, Proj4, GEOS). When I unzip the PostGIS tar, then ...
5
votes
2answers
2k views

Geodatabase to PostGIS character encoding

Similar to another question I posted previously, I'm trying to import datasets from Esri geodatabases into a PostGIS database directly, and inside the data there are greek letters and symbols that are ...
5
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2answers
902 views

How does shp2pgsql define schema?

Can anyone explain how it is that the shp2pgsql loader for loading shapefiles into PostGIS goes about defining the schema for a table when importing a shapefile? To further explain, shapefiles are ...
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2answers
2k views

How to convert OSM Data to PostgreSQL for Routing Purposes?

I'm creating a routing application using OpenStreetMap. Currently, my task is to convert the data from an OSM file to PostgreSQL. I read about osm2pgsql, but the problem is it says there that ...
11
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2answers
3k views

How to import esri Personal Geodatabase (.mdb) to PostGIS on Linux

We have esri Personal Geodatabases that we need to import into PostGIS. Ultimately, we'd like to allow people to upload an MDB on a web server, and have it import the layers into PostGIS. On ...
4
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1answer
2k views

Using PostGIS with Rails

I'm new to postGIS, and am looking to use a spatial database with my Rails app (specifically, to retrieve points from the database that are within the bounding box of a Google Maps viewport). I posted ...
8
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2answers
704 views

Splitting polylines using regions with PostGIS

I was wondering if it is possible to split a polyline on polygon boundaries (regions) in PostGIS, the picture below is of what we have at the moment and showing where I need the polylines split: ...
8
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1answer
1k views

PostGIS 3D in Action

I was wondering if there is a website that showcases Openlayers and PostGIS 3D in Action
13
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3answers
7k views

Is there a dissolve function in PostGIS other than st_union?

I'm looking for a function to dissolve shared boundaries between polygon features in a table. ST_UNION() almost does what I'm looking for, but it creates a multipolygon from all polygons in the layer ...
4
votes
2answers
848 views

ArcSDE 10 and PostgreSQL 8.3 vs 8.4

We have recently upgraded our ArcSDE 9.3 instance to ArcSDE 10. I was hoping to upgrade postgresql 8.3 to 8.4 at the same time. Although ArcSDE 10 supports 8.4, it turns out that the ArcSDE wizards ...
13
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4answers
4k views

How to create one-sided buffers or parallel lines in PostGIS?

I'm looking for a way to create so-called one-sided buffers or parallel lines in PostGIS. Example: 1. buffer, 2. one-side, 3. both-sides I've found some discussion on the mailing list from 2009 and ...
20
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7answers
8k views

Options for displaying PostGIS vectors in OpenLayers

I am very new to web-mapping, so this question may be a little misguided. I want to have a very simple web interface using OpenLayers (or even Google Maps if that will be easier) which can display a ...
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6answers
2k views

How can I connect to a PostGIS database from ArcCatalog 9.3 via ArcSDE?

I have a problem connecting to my postgis database via ArcSDE in Arc Catalog. When i want to establish connection to my database i get an error:
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4answers
1k views

Queries returning very big datasets in PostGIS

I have a PostGIS query that will return several million rows: SELECT t1.id AS id1, t2.id AS id2, ABS(t1.mean_h - t2.mean_h) AS h_diff, ST_Distance(t1.the_geom, t2.the_geom) AS dist FROM ...
9
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2answers
1k views

What are the implications of invalid geometries

I've imported some data in a Postgis database and some of the geometries are reported invalid (ST_IsValidReason reports self-intersection or ring self-intersection). The queries I am performing don't ...
8
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3answers
2k views

How to emulate Google Maps driving directions using pgRouting?

Would like to emulate google maps' driving directions functionality but use pgRouting instead. google's data over the project area & scale is quite a bit off so we want to use our own transport ...
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4answers
3k views

Live KML from PostGIS to Google Earth

I was wondering if anyone knew a way to bring data from a postGIS database into Google earth to view live. I know of the asKml function in PostGIS, but I'm interested to know if anyone had managed ...
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2answers
5k views

How can I find a point inside a polygon in PostGIS?

How can I find a point that is guaranteed to be within a given polygon in PostGIS? I am aware of the ST_Centroid function. However, the centroid is not always within a polygon, see below: ...
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2answers
4k views

How can I calculate the bearing between two points in PostGIS?

How can I find the bearing between two points in PostGIS? Please specify in your answer whether or not the method producing a bearing on the spheroid, or a planar bearing.
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4answers
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struggling with GeoDjango install: ERROR: could not access file “$libdir/postgis-1.5”: No such file

I'm installing GeoDjango on Mac OSX. I've followed the official Mac install instructions, which all went smoothly, and am now creating a spatial database template for PostGIS. However, when I try to ...
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2answers
1k views

Unions of polygons (Postgis ST_UNION for Geography type)

I am looking for a function that will return the intersection of 2 or more polygons (geography type). I am aware of ST_UNION, ST_COLLECT but it works only for geometry type. Any tip will be really ...
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vote
1answer
843 views

psycopg2 error with QGIS 1.5

So I just installed QGIS 1.5 using the windows installer not the osgeo4w one and now any plugins that need access to PostgreSQL databases don't seem to work, they all throw a: "Couldn't import Python ...
2
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1answer
444 views

How to convert SHP/POSTGIS data into x, y, z, “cost” data?

Is there a way to convert a line layer (shp or PostGIS) data into (x, y , z, cost) i.e. (From_node, To_node, optional_Elevation, Cost/Weight) ?
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votes
3answers
2k views

Writing a plugin for Qgis using python to access PostGIS and write geometries

Sorry about the strange title didn't really know how to word it. I currently use MapInfo to do most of my GIS work however I have recently installed PostGIS 1.5 and am really liking it so far. A ...
20
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7answers
7k views

Nearest neighbor between a point layer and a line layer

I've asked this question several times on stackoverflow and irc between #qgis and #postgis and I also tried to code it or implement it my self in postgis with no real answer. Using programming (most ...
3
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1answer
581 views

Find polygon that contains all linestring records in PostGIS table

I'm still pretty new to this stuff, so bear with me. In PostGIS how could I find a polygon that would contain all the linestring records in a given table?
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10answers
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Alternatives to pgRouting

I was wondering if there are any alternatives to pgRouting tools. Thinking about it for a bit, I think the only alternative is to use R or RPY to do the analysis. Basically I'm trying to solve ...
15
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4answers
3k views

Simplifying adjacent polygons

I encountered a problem simplifying set of polygons that are adjacent. If I simplify each polygon separately with the Douglas–Peucker algorithm (which is used by many open source tools), the resulting ...
11
votes
4answers
3k views

Simplifying polygons to linestring

I would like to simplify some polygons that represent rivers into linestrings. I assume that holes in polygons can be omitted. Anybody has some good idea how to simply do it? It would be nice, if it ...
26
votes
9answers
15k views

How to connect to PostGIS database from ArcMap?

How can I connect to a PostGIS database from ArcMap? Solutions for ArcGIS 9.3, 10.0 and later are acceptable. Ideally, I would like to be able to perform spatially enabled queries and receive the ...
21
votes
4answers
6k views

Separate polygons based on intersection using PostGIS

I have a PostGIS table of polygons where some intersect with one another. This is what I'm trying to do: For a given polygon selected by id, give me all of the polygons that intersect. Basically, ...