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

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How to resolve case when routing result does not contain start and end point?

I have routing case shown on picture, SP=start point, EP=end point. A-----SP-----B------------C----------D--------E-----EP------F Routing result is BC, CD and DE. My points are not on route. I think ...
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1k views

POSTGIS query of point feature. How to find nearest point to query location?

I am querying a point feature using a POSTGIS request fired in Javascript. The decoded URL looks like this and returns great results for polygon features. ...
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5k views

How to display a PostGIS table on Google maps?

I am attempting to take a shape file and display it on a map: I can do something like this: SELECT ST_AsText((ST_Dump(the_geom)).geom) as the_geom FROM shapes; But the problem is I still have to ...
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1answer
289 views

PostGIS Raster convolution filters

I've looked through the PostGIS raster documentation, but can't find an indication of how to apply a convolution filter to raster data. Does this capability even exist (yet?) There only appears to be ...
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726 views

Storing Polygons in PostGIS (data coming from shape files)

We want to store data from shape files in PostGIS all in one table. There will be two columns in the table: boundary - The polygon data (How do we store this?) mongo_id - Links to a mongo database ...
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335 views

shp2pgsql srid 2262 polygons NOT in geocordinates

Imported the following shape file: shp2pgsql -c -s 2262 MCGIS_Towns_Villages public.towns | pgsql -d database Queried: SELECT gid, name,st_astext(the_geom) as the_geom FROM towns The ...
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1answer
2k views

display multiple vector layers from single PostGis table in GeoServer using OpenLayers — REWORDED

Prompting suggestions I’m going to attempt to reword my question I have a PostGis table that contains overlapping vector polygons. I need to display a selection in Geoserver and provide ...
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2answers
1k views

Projecting OpenStreetMap data in PostGIS

I've loaded an extract of Openstreetmap data into a Postgresql database with PostGIS 1.5 using the following command withosm2pgsql.exe: C:\Program Files (x86)\HOTOSM\bin>osm2pgsql.exe -c -s -H ...
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369 views

How can I put OSM data in a geography view in PostGIS?

I loaded the *.osm file to postgis with osm2pgsql. The data are stored in lat/long, so the same time I expect them to should be available in geography view, but they are not (only present in geometry ...
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3k views

How do I perform a proximity search with Postgis?

OK, so I downloaded the Geonames database (cities1000) and wrote a small Ruby program to import them into my table (geo_cities). I then added geography column called geog. So after all of that, I ...
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290 views

Ways and Vertices tables empty after osm2pgrouting tutorial

I've been following the osm2pgrouting tutorial, have compiled osm2pgrouting with necessary boost and expat libs installed, and built a postgresql db with support for postgis and pgrouting. Importing ...
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2k views

Issue merging multiple polygons using ST_UNION

I've got regional data loaded into a PostGIS table and want to merge regions that share the same parent name (and ultimately output the data as KML.) This is my query (I'm using php): SELECT ...
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1k views

How can I deploy a custom GeoTools datastore to GeoServer?

I'm using GeoTools v8.0 and GeoServer v2.1.3. I've currently built a working datastore connecting to a PostGIS database based off of the GeotTools' abstract datastore tutorial. After days of on and ...
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1answer
989 views

Failing to build PostGIS on Mac OS X 10.6.8 (Snow Leopard)

I'm getting the same problem expressed here Failing to build PostGIS on OS X 10.7 Lion But in Mac OS X Snow Leopard. Things I have checked include: PostgreSQL compiled to several architectures. I ...
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1answer
1k views

PostGIS UPDATE Statement with ST_Contains(table1.geom, table2.geom)

I'm strugeling with a query I should write to UPDATE my dataset. First of all, I have 2 tables containing data and I need to mix it. Tabel 1 -- lets call it names: name_str the_geom (points) ...
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3answers
794 views

WFS Caching / Back button

I'm using WFS protocol on Vector layer / GeoServer / PostGIS Currently the map is refreshing and calling new requests whenever i do anything like searching or drawing and when i move back to a part ...
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2answers
2k views

How to insert geometries from shapefile into existing table?

I'm running into a problem trying to figure out how I should insert a GIS coverage polygon into an existing table. I'm primarily using QGIS and the PostGIS Manager plugin to handle it. After some ...
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1answer
233 views

Not seeing the actual data value in getObservation response from MapServer 6

I'm experimenting with MapServer and SOS but I'm not getting back any useful data from the GetObservation call I'm doing. My .map file uses a Postgres query to get data and when I run that same query ...
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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 ...
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1answer
228 views

identifying single overlaping features from a GeoServer layer

I'm trying to use GeoServer to display features from a PostGis table the url will look similar to this. Example URL ...
3
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1answer
480 views

making choropleth maps using PostGIS Windows

i read an article on chicago tribune blog about making maps, it consist on "making choropleth maps using PostGIS, TileMill, Mapnik and Google Maps" on Mac environnement, my question is how we can ...
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222 views

Running database operations against a stored GIS geometry

I'm using Quantum GIS and Postgres with the GIS extensions to store shapefiles that I'd like to run point in geometry and point in union geometries against. While it's easy to save and load the vector ...
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62 views

postgis minimum distance among many points [duplicate]

Possible Duplicate: Nearest Neighbor calculation in PostGIS Is there a way to achieve the following: SELECT ST_AsText(a.geometry), min(ST_Distance(ST_GeomFromText('POINT(10 20)'), ...
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38 views

Does Shooting star 1.05 not consider reverse_cost? [duplicate]

Possible Duplicate: PGRouting with 1.05 library in Postgres 9.1 Shooting star pgrouting lib 1.05 with postgres 9.1. Dijkstra and A-star working fine but "SHOOTING STAR" not considering ...
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2k views

How to implement feature search in OpenLayers with Geoserver?

I'm looking to build an application similar to this ArcGIS Server JS example which does a find task against a layer in the map. However i want to do this with OpenLayers, Geoserver and PostGIS. Some ...
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4k views

Identifying road intersections using PostGIS

I'm trying to identify where roads intersect each other, and to make a point at this intersection, with the number of roads that form the intersection listed. I was wondering if there was some way ...
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142 views

How to prevent base layers from being edited?

I've made a local tile server (mapnik + postgis + tilecache). Now i need to make use of some editing tool so that only newly created layer can be edited: users of this tool shouldn't have rights to ...
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2answers
855 views

Is Shooting Star broken in PGRouting 1.05?

I'm using pgrouting DLL 1.05 with postgresql 9.1. All required function installed. Astar and Dijkstra work fine with sample data but "SHOOTING STAR" is not considering "reverse_cost". Also if i try ...
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2answers
3k views

ogr2ogr kml to shp conversion created 184 shapefiles?! What am I missing?

I'm trying to convert this KML dataset of ice arenas to a shapefile using ogr2ogr (GDAL 1.8). After some initial troubleshooting to get the script running, it's creating 184 different shapefiles (736 ...
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1answer
212 views

Is it be possible to re-render parts of a tile pyramid when postgis table updates?

I have this idea of using postgis together with a tile renderer for serving my organization with tiled maps. As I believe my data will be partially altered almost on a daily basis it does feel like a ...
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2k views

Why do simplify polygon results differ between ArcGIS for Desktop and PostGIS?

I am mainly interested in why and how the Simplify Polygons tool in ArcGIS for Desktop handles the simplification process, including preventing and resolving topological errors better than the ...
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1answer
2k views

How to choose between Markers and Features for drawing Openlayers objects?

Yesterday I was trying to create first mock-ups of my GPS tracker interface, and was exploring the available OpenLayers objects for drawing on a map. I began with simple task - placing a marker on a ...
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1answer
2k views

How to perform a spatial join of point and polygon layers in PostGIS?

I have a point dataset representing households that I want to associate with a parcel layer (i.e. assign its parcel_id). With ArcMap, I could spatially join the polygons to the points and specify that ...
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246 views

I am getting a blank layer preview from geoserver after Quick Exporting my shapefile to postgis and then getting postgis to point to geoserver [closed]

What could be the potential problems? Looking at the layer's data fields/form the one thing that isn't filled is the Native SRS and its source, but I have already passed in the projection info as it ...
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2answers
167 views

After two buffers operations (+/-), why is the result file bigger than the original?

First file ( .shp ) had 1000KB, after 2buffers ( buffers on polygon, 1st buffer +100, 2nd buffer -100 ( small things near polygon should be removed )) in quantum gis file grown to 1500KB, and after ...
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2answers
3k views

Using OpenLayers (with OpenStreetMaps) and PostGis for rendering data acquired from GPS tracking device?

I'm researching and planing to acquire data from GPS device and store them in postGIS database, then use geodjango to process/work them out and finally chart them on a map with OpenLayers. Will these ...
3
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1answer
999 views

How to use the pgRouting TSP function?

For more than two days I'm trying to make the TSP algorithm work in PostgreSQL/PostGIS. My problem seems to occur when I'm trying to take into account the road network for TSP algorithm. I know that ...
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2answers
3k views

Is it possible to get the EPSG value from an OSR SpatialReference class using the OGR Python API?

When reading a layer from a OGR PostGIS connection I can get the SpatialReference of the layer, but is it possible to get the EPSG value? Is there any documentation on this? For example: lyr = ...
23
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3answers
7k views

How can I calculate the average width of a polygon?

I'm interested in examining the average width of a polygon that represents the road surface. I also have the road centerline as a vector (which is sometimes not exactly in the center). In this example ...
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3answers
1k views

How to route between lat/lon pairs in pgRouting?

I have set up Postgresql, PostGIS and pgrouting on Ubuntu. I have imported an osm for wales using the following command: ./osm2pgrouting -file wales.osm \ -conf ...
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1answer
623 views

Enhance performance of a join query for mapnik using postgis

I use mapnik to render map with datasources from a postgis database. One query is a join on two table, one with a geometry (a polygon) and the other one with some fields I want to use for rendering. ...
2
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1answer
365 views

PostgreSQL / PgRouting syntax error

My question is about Postgres/PgRouting syntax, when I wrote query like this: SELECT * FROM shortest_path('SELECT gid AS id, source::int4 AS source, target::int4 AS target, ...
5
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1answer
393 views

Spatial index vs two coordinates indexes

I have a table with two columns: latitude and longitude. I want to get all objects inside a "rectangular" (well, rectangular in a lat/lon coordinate metric) bounding box: min-max latitude and min-max ...
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5answers
5k views

What causes this unexpectedly poor GeoServer/PostGIS/OpenLayers performance?

I am having a tough time making this map run smoothly (play around with it for a bit, you'll see). I have taken a few tips from OSGeo's Making Maps Fast document, but I think there's another issue ...
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2answers
6k views

How to install PostGIS shp2pgsql-gui on CentOS 6?

I am installing PostGIS 1.5.3 on a CentOS 6.2 virtual machine to get started web mapping with Geoserver.I have successfully installed PostgreSQL 9.1, PostGIS 1.5.3 and PgAdminIII on the system. ...
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2answers
845 views

How to use pgRouting's dijkstra_sp_delta_directed with WHERE clause?

Right now I am using PgRouting for vehicle routing and I have problem with Dijkstra shortest path. My query is: SELECT * FROM shortest_path('SELECT gid AS id, source::int4 AS source, ...
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3answers
13k views

How to convert MultiLinestring to Linestring?

I have a multiline string and want to convert it to a linestring in order to use some functions that only work with linestrings. I used ST_Dump() and got a collection of my geometries. If I merge them ...
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1answer
271 views

Vertex point is returning None

I have this multilinestring that has 48 NPoints. When I execute ST_PointN(line,5) it returns none. And to continue on, it returns None for everything after index:2 up to index:48. This is how my line ...
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3answers
5k views

How to fix performance problem in PostGIS ST_Intersects?

I'm a newbie in postgis and I have a problem in query performance. This my query: SELECT DISTINCT ON (userid) userid ,ST_AsText(position), timestamp FROM table1 WHERE ST_Intersects ( ...
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1answer
1k views

How to detect overlapping linestrings in PostGIS?

I'm looking for the fastest way to detect whether a given linestring overlaps another linestring. (As reference, let's say my wife and I both go for a run and take different routes, I'd like to detect ...