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

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TileStache Dynamic query based on zoom level

I wanted to make tilestache to be able have a different query for different zoom level. For certain zoom level I wanted TileStache to query from different postgres table. How can I achieve this? Is ...
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Can't set cache on tilestache

I've successfully installed tilestache on my server and able to load a geojson from it. But when I change the config file to use disk cache, the server return 500 on requesting the tiles. What I add ...
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695 views

clustering points in postgresql to create contour map

UPDATE: To try to make this a little more simple, is it possible to create a query which selects a group of points such that each point in the group is at most X units away from at least one other ...
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17 views

Intersection of two vector tables data in postgresql

I have satellite raster data is converted in to pixels using create table gtru_tile_pix as SELECT (ST_PixelAsPolygons(rast)).val, (ST_PixelAsPolygons(rast)).geom FROM ...
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35 views

PostGIS connect points to 1 closing/bounding line

I have this points represented as geom: And when I apply: ST_MakeLine(points.geom) I got this: When I need something like closing/bounding line (and even better the whole area as 1 geom): ...
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157 views

Admin Sample GXP Viewer

I have Geospatial application which is using GXP, GeoServer, GeoExt and PostgisSQL. We would like to enhance the application by adding a user friendly Admin system, similar to what GeoNode has. This ...
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1answer
32 views

PostGIS: Simple query selecting nodes of polygon

I know it's very simple but anyway: (Asked also at stackoverflow) INPUT: Regular OSM buildings .shp table PostGIS Point location RADIUS (around above location), lets say 500m. RESULT: I want to ...
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3answers
159 views

Which tool/referecence for adress geocoding?

I have to geocode several corporate sites (a big excel file), near to Paris (FRANCE). I would like to geocode this file based on the addresses. Could you tell me the best tool for this task ...
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1answer
18 views

Tile server return empty features

I have successfully installed tilestache. I also has succesfully add a layer using shapefile from here. But when I tried to use my own shapefile, the server always return empty featurecollection. I ...
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1answer
30 views

transform MULTILINESTRINGs to curves in cartodb

I have a table with a column that contains MULTILINESTRINGs, where every string contains the longitude and latitude of a starting- and an end point, e.g.: MULTILINESTRING((97.0253024 ...
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1answer
24 views

QGIS is not starting because of deleted file libgeos_c.so.1,How can I fix it

QGIS is not starting because of deleted file libgeos_c.so.1,How can I fix it It was originally running but some how I have deleted this file for some porpose installation of postgis for postgress but ...
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1answer
91 views

How to speed up raster/map algebra in PostGIS?

I am testing map algebra with PostGIS (2.1 with PostgreSQL 9.3) on two images, and found it to be rather slow. For example, dividing two images of 7200 * 3600 pixels took 110 ~ 120s on a desktop with ...
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386 views

Drawing curved lines in CartoDB?

I am experimenting drawing curved line from Origin to Destination in Cartodb. I was able to do so once, however, failed the second and third time. Could anyone offer me some insights into the ...
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1answer
456 views

Using ST_MakeEnvelope over the dateline

I'm using ST_MakeEnvelope in PostGIS to try and make geometries that cross the international dateline, but they are making a shape that wraps the other way around the globe. The geometry I want is ...
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1answer
28 views

Average distances between two point sets bound by polygon

I have a table of boundary polygons, a table of points and a table of other_points I want to work out the average distance between points contained within and other_points for each polygon. So far I ...
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1answer
38 views

Couldn't Excute command line PostGIS pgsql2shp

I am using postgres 9.3 with postgis 2.1 on Ubuntu 14. When I tried to dump pgsql table using pgsql2shp, I get the following error. Error: pg_wrapper: pgsql2shp was not found in ...
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2answers
149 views

pgr_dijkstra function not finding node that appears in ways table

I am having a problem with pgr_dijkstra algorithm not finding some of the node vertices in my table. I have a large dataset of survey travel diaries and am trying to determine their shortest paths ...
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1answer
38 views

How can I export a shapefile from PostGIS with a GeoJSON query?

I tried to export a shapefile from my PostGIS installation using pgsql2shp as follow pgsql2shp -f tiles.shp -h <host> -u <user> -P <pass> <database> "SELECT id, the_geom FROM ...
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1answer
28 views

Django Postgis Distance from point

I have a point where the objcet is and another point for mylocation. I want to calculate the distance >> object_location <Point object at 0x7f9ceaac7be0> >> mylocation <Point ...
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2answers
219 views

Collecting multipolygons into a single multipolygon with ST_Collect() in PostGIS

I would like to collect 50,000 individual multipolygons into one big multipolygon. Unfortunately when I perform ST_Collect(geom) it bundles them into a geometry collection and cannot be cast as ...
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2answers
111 views

How can I generate batch of coordinates from linestring to simulate driving on map?

I have a openlayers map and I want to simulate driving a route on it. I would like to draw a line (using GPX tool) and create gps coordinates (preferred with advancing time stamp) so I can query them ...
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2answers
45 views

Rasters loaded in Postgres/PostGIS using raster2pgsql contain blank lines

I recently set up an Ubuntu Server as a Postgres/PostGIS database server. In an effort to serve a collection of aerial photos to my colleagues, I loaded 608 GeoTiffs (non-overlapping 1km tiles each ...
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169 views

Delete all data from a PostGIS topology

I need to delete everything (faces, nodes, edges, anything I'm not thinking of) from a PostGIS topology, but I want to keep my database schema (schemas, tables, columns, sequences, etc.) intact. Is ...
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1answer
28 views

add geometry to MULTILINESTRING in cartodb

I have a table that contains a column with MULTILINESTRINGS (which are the coordinates from two places (i.e. long0,lat0,long1,lat1), like this: MULTILINESTRING((97.0253024 4.3685491,8.5618685 ...
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1answer
47 views

Slow Planning for Postgis ST_Intersects

I am trying to run the following query: SELECT * FROM fences where ST_Intersects(geom, ST_GeomFromText('POINT(-73.990452 40.994184)', 4326)) When I run Explain Analyze I get the following: "Index ...
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1answer
154 views

QGIS There isn't entry in geometry_columns!

In PostgreSQL v9.3 with PostGIS v2.1 extensions I created a view from two tables (sites & visits). The site table contained a point geometry column (the_geom), which was included in the created ...
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23 views

PostGIS: Compute isovist

I'm using PostGIS with OSM table of buildings. How can I compute isovist from single location point while only the buildings (represnted as geom's) are the obstacles. Thanks,
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2answers
59 views

how to snap points to lines in QGIS/PostGIS?

I'm attempting to snap approximately 900 points to a line table. I've tried recreating what I have found from a couple of PostGIS answers but not having much luck. To test, I've created two ...
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1answer
51 views

Performance Improvement of Postgres vs PostGIS

I am trying to run the following query thousands of times per second to determine which is any polygon contains the passed in point. SELECT * from areas WHERE poly @> ? Poly is the name of the ...
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1answer
33 views

Multipolygon From Multilinestring PostGis

I have been looking for a answer for days. I dont even know if its possible. Tried: ST_AsGeoJson(ST_MakePolygon(ST_transform(geom,4326))) ERROR: Shell is not a line ...
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3answers
598 views

Importing MaxSea 3D Database to PostGIS

I am currently working on a project, where I combine several MaxSea 3D databases, which contain depth measurements made by the echosounder onboard on a ship. The idea is to combine these databases to ...
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2k views

What format is lat/long stored in OSM PostGIS?

Question: How do I to get the lat, long for all the toll booths stored in OSM for Virginia? Current Query: > gis=# select * from planet_osm_nodes where ('toll_booth' = ANY(tags)); id ...
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31 views

Convert Postgresql Polygon to PostGIS POLYGON

I have an existing table in postgres which contains a plain old posgresql polygon. I have added a new column using SELECT AddGeometryColumn ('public','fences','geom',4326,'POLYGON',2); I would ...
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1answer
58 views

Converting from kilometers to degrees distances?

We have geometries in a Postgis database with SRID WGS84 and we have found lookups directly in degrees to be much faster than in kilometres, because the database can skip the projections I would ...
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22 views

Collect near polygons [closed]

I have the following data: The data have 5 level (in tones blue). I want to collect only the nearest polygons with the same level and sum the number (represent client number). When I collect only ...
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0answers
32 views

How do I optimise performance on a local QGIS + PostGIS installation?

I'm learning how to manage a local PostGIS (ver 2.1) database, with spatial indexing enabled on the shapefiles that I've imported (using the PostGIS Shapefile Import/Export Manager). I have imported a ...
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2answers
960 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 ...
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2answers
108 views

Cleaning geometries in PostGIS?

I am trying to do some processing on some very large polygon layers. However I am running into various geometry errors such as: NOTICE: Ring Self-intersection at or near point 470396.52017068537 ...
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1answer
30 views

How to store multi-valued attributes in PostGis using Postgresql [closed]

I have a with meterid,meterreading,reader and date read.I wish to store this data using Postgis database. I used this code via postgresql to create the table CREATE TABLE MeterRdg( meterid ...
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GeoWebCache Speed SQL Server Store

How to increase GeoWebCache speed, Am using geoserver 2.7.2 for tile cache and data store creating from a SQL Server database it will take 1 day and above to complete cache and it terminated several ...
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how to use st_intersection() with re-projection in POSTGIS?

This is a shipping route from 'portland to busan' and I want to check the route against land_polygons like how much distance is traveled by a route through land.And the problem is while checking the ...
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1answer
161 views

How to get a distinct pair of column values based on minimum of another (computed) column?

I have two tables with point geo data, one (sfc_obs) with weather stations (names), one (smos_grid) with satellite pixels (dggs), and I'm trying to find which dgg is closest to each name using ...
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30 views

Alpha Shapes in pgRouting - missing FROM-clause

I am attempting to follow Anita Grazer's post on creating alpha shapes in pgRouting. The article was written several years ago, so some of the functions have been updated and names have changed. I ...
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1answer
323 views

Building web application to get PostGIS query from user and view result map using GeoServer via OpenLayers?

I'm a newbie in web-map application area. I just found the small application in this tutorial interesting I am a bit confused, because when i publish a map using geoserver and openlayer, I have to ...
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1answer
161 views

Mapserver openlayer postgis spatial data are in postgis but label I want to display from webservice

My database of spatial data wkb is in postgis and my textual data is in sqlserver now is it possible to show labels through webservice. I have common id in both the database through which I can join ...
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25 views

PostGIS dijkstra routing - specifying source and target as bigint instead of int4?

I'm currently working on a problem where I have to use PostGIS's pgr_dijkstra to calculate the shortest route from a starting point to a destination, and then use ST_AsGeoJSON to convert the route to ...
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2answers
199 views

Password Protect QGIS project

On a shared computer, I have a QGIS project which links up to a PostGIS database that contains my data. If a user wants to access layers from the db, they have to enter the db credentials, so that's ...
5
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2answers
128 views

QGIS expression builder include relation attributes

I have a set of symbols based on a table in postgis such as this id|type|action_1|action_2|geom In QGIS I have this table symbolised using a rule expression which works effectively. However this ...
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10 views

collada2pgsql: importing 3d models into postgis

I have been researching for a tool (open source) for importing collada (.dae) file into postgis and i have found this collada2pgsql command. I really don't know where to find it but it seems to be ...
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1answer
300 views

How to visualize measure values along linestrings in QGIS?

I have a series of LineStringM geometries. The measure value represents slope (or stream gradient) at each point in the geometry. I love QGIS's robust styling options, but I can't find a way to render ...