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

learn more… | top users | synonyms

3
votes
3answers
185 views

How can I draw squares in PostGIS layers at different angles?

I am trying to draw two squares on a 45-degree angle and then merge them using PostGIS to edit. QGIS can draw squares but only on a perpendicular plane (eg, 0, 90, 180), and I need to be able to draw ...
3
votes
0answers
424 views

How can I properly add PostGIS data into MapGuide Maestro?

I am having trouble connecting a PostGIS database to MapGuide Maestro. Actually, I have added the PostGIS data into Maestro, but when I click to validate the layer it shows an error message: ...
3
votes
2answers
3k views

Postgis installation error

I am using fedora machine. I want to install postgis on my system. So this is what I have done Installed Postgresql and supporting packages using YUM. Created directory /sources to put all the ...
2
votes
2answers
180 views

Postgis, get the points that are x meters near another point, in meters

I'm trying to find the points within a certain distance, in meters, from another point. I'm using the function ST_Buffer, but I don't get how to express the distance in meters. I'm trying with ...
2
votes
1answer
681 views

Why does my PostGIS query fail with “current transaction is aborted”

I'm trying to create a vector layer in a QGIS project using a PostGIS query. QGIS is returning the following error: Query failed 1 cursor states lost. SQL: CLOSE qgisf1 Result: 7 (ERROR: ...
2
votes
1answer
188 views

Automated correction of parcel geometry based on area measure

i have a set of parcels in DWG file and i have the areas that should be in these parcels in an excel file, so i have to modify each parcel to match the area specified in the excel file with a moving ...
1
vote
1answer
640 views

GeoServer WPS Aggregation Functions Example

The scenario: I want to present a user with names of polygons from a layer in GeoServer. I then display the polygon(s) whose name(s) the user selected. What I've done: I have a search box, which ...
1
vote
2answers
823 views

DatabaseError: Coordinate values are out of range [-180 -90, 180 90] for GEOGRAHY type

I am using Django 1.3, PostGIS 2.0 , Postgresql 9.0 and GeoDjango. I had a database with a table for places. This table had latitude and longitude for places in the US. I enabled this database with ...
0
votes
1answer
63 views

PostGIS: ST_Clip() raster in SRID:32617 with a polygon

I'm trying to ST_Clip() raster in `SRID:32617' with a polygon. What I did ST_Transform(polygon, 32617): It fails, couldn't project point() exceeded limit (-14) ST_Transform(rast, 4326, ...
0
votes
1answer
159 views

Coordinate values are out of range [-180 -90, 180 90] for GEOGRAPHY type

After import some data from OSM file into Postgre, the coordinates numbers are too big and having trouble to cast to Geography: Coordinate values are out of range [-180 -90, 180 90] for GEOGRAPHY ...
0
votes
0answers
71 views

not able to view imported .tif file in geoserver

I am using geoserver. I have imported a .tif file using postgis, which has been saved in vector type layer in geoserver. Now, whenever, I preview it, the layer gets automatically downloaded as wms ...
21
votes
3answers
7k views

Best GIS system for high performance web application - PostGIS vs MongoDB

I am working on a web/mobile application based on location data. Since i am already familiar with MongoDB, i found the geospatial indexing of mongo is quite suitable for my needs. As i am mainly ...
18
votes
7answers
1k views

Spatial databases learning resources for newbies

Would be taking up a course on spatial databases next semester. Would anybody know a newbie friendly introductory resource? A vendor neutral one would be preferable. Thanks.
9
votes
1answer
5k views

Geocode quality: Nominatim vs. PostGIS Geocoder vs. Geocoder::US 2.0

I occasionally need to geocode >> 500,000 US street addresses (no features or intersections). I'd like to set up a geocoding service locally to handle these bulk geocodes. I've used the Tiger-based ...
18
votes
1answer
2k views

Comparison of geocoding solutions (such as Gisgraphy & PostGIS 2.0)

As I am sure many of you are aware, PostGIS has finally released Version 2.0 and included within this version they have also built a geocoder (see: http://postgis.net/docs/Extras.html). Although I ...
16
votes
2answers
3k 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: ...
14
votes
5answers
1k views

Find pseudo nodes in free GIS software

Software gvSIG OA Digital Edition 2010 have tools topology for finding pseudo nodes in linear geometry. I set cluster tolerance 0.00002 and maximum number of errors -10000 for 20000 link count linear ...
17
votes
6answers
2k views

How do I get started with GIS Servers on Amazon EC2?

Are there any tutorials, talks or presentations that discuss the use of EC2 or other cloud computing services to host GIS Servers? Has anyone had any experience in doing it with Amazon's EC2? How hard ...
13
votes
1answer
830 views

Identifying topological relationships using PostGIS

I'm trying to perform a basic typology analysis using PostGIS. My objective is to find any polygons that touch other polygons. To do this, I thought the ST_GetFaceEdges would work (reference). I want ...
11
votes
2answers
1k views

How to calculate the angle at which two lines intersect in PostGIS?

I want to calculate the angle between two lines where they intersect in PostGIS. The starting point for angle calculations in PostGIS seems to be ST_Azimuth - but that takes points as input. My first ...
17
votes
2answers
1k views

Moving a PostGIS Installation

I have a simple question: I have a postGIS installation running on an old computer that I'd like to move. I spent a bunch of time playing with pg_dump and pg_dumpall without success. It seems the ...
12
votes
3answers
660 views

PgRouting - How to clip links when reaching max costs?

I have a polyline shapefile representing a road network and a second shapefile containing points. I would like to use PostGIS (presumably PgRouting) to identify sub-networks or service areas radiating ...
11
votes
1answer
521 views

Nearest Neighbor Grouped Selection in QGIS

OK - so I have an interesting problem I am trying to solve. I have a list containing over 100,000 points in lat/long format which I have imported into qgis. Now, what I am trying to do here is group ...
8
votes
4answers
642 views

What is the best web editor and server for postgis?

I'm looking for a web editor (similar to openstreetmap) that works with an map Server (postGIS). This should permit edit and create new structures on map. What is the best option? Can you help me? ...
13
votes
3answers
1k views

Visualization of 3D shapefiles with Mapserver and Postgis

I'm wondering is there a way to visualize 3d data with mapserver? 3D .shp files are in postgis database, and I already connected mapserver to database, but with simple layer in mapfile.
10
votes
2answers
368 views

How to identify and simplify point clusters with regard to time in PostGIS?

I just started to work with spatial databases and I want to write a SQL(PostGIS) query for automatic generalizing of raw GPS-tracks (with fixed tracking frequency). The first thing I am wokring on is ...
10
votes
6answers
2k views

Should I use a CMS for my web mapping application?

For my web mapping app, I am using GeoServer as server, PostGIS as spatial DB and OpenLayers on client side (as well as other JS libraries). The map is composed of base maps and vector layers. One of ...
7
votes
2answers
523 views

Version editing for Postgresql 9.2.4 / postGIS 2

Background: I am "building" a GIS with PostgreSQL 9.2.4 / PostGIS 2 as the database and QGIS 1.8.0 as the geographic application. There will be multiple users accessing, editing and viewing the data ...
14
votes
4answers
13k views

Why does PostGIS installation not create a template_postgis

I went this route for installation of PostgreSQL and PostGIS: PostgreSQL using the standalone KyngChaos, PostGIS install from KyngChaos as well... pgAdmin3 from PostgreSQL Tools Now when I launch ...
14
votes
2answers
3k views

What are hardware requirements for a cloud hosted PostGIS & GeoServer?

I have been playing with a local installation of PostGIS & GeoServer. I would like to move my work online now to share it with several collaborators. The proof of the concept map will consist of ...
13
votes
3answers
911 views

Is there a CASE Tool for modelling spatial databases?

Does anyone knows if there is a CASE Tool that would be possible for modelling spatial tables? I need to create a model and export it to SQL or a database directly. I´m using PostGIS. Thanks in ...
12
votes
2answers
428 views

PostGIS interpolation / triangulation options

I'm looking for an open source workflow to automate DEM construction. We have a series of sites that fall within a LIDAR dataset. We want to create site specific DEM's for each site, and we're ...
11
votes
4answers
915 views

Large shapefile to raster

I have a large shapefile (1 gb) and need to rasterise it. I have tried the following already. 1.) Import it into GRASS using v.in.ogr this failed with the error message: ERROR: G_realloc: unable to ...
9
votes
2answers
408 views

Are there Desktop GIS alternatives to ArcGIS 10.X for topology and vector conflation?

Is there any options other than ArcGIS for Desktop for topological rules and automatic topology integrity enforcing in a Desktop GIS? I am looking for something that will automatically snap features ...
9
votes
3answers
1k views

How to populate an undirected graph from PostGIS?

This question is more related to resources that I might not have identified yet, although I've been searching the web for a while. In the project I'm working at the moment I need to run a ...
8
votes
2answers
447 views

PostGIS Intermittent INDEX Performance

I have a table containing approximately 55 million data points ( point is a geometry with SRID 4326 ) and for my query I need to join this to an area table ( currently have ~1800 areas ) which ...
8
votes
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 ...
7
votes
2answers
3k views

Spatially enabled Postgres database

I am trying to create a spatially enabled PostGIS database. I am following the PostGIS documentation, http://postgis.net/docs/manual-1.5/ch02.html#id2648455. In the short version, i executed, ...
7
votes
1answer
690 views

PostGIS Intersection and Summarise Attributes

I am usually an ArcGIS desktop user, but keen to start using PostGIS more and I have a really big bit of processing to do. Not sure what functions to use, hopefully someone can help. I have a polygon ...
6
votes
1answer
2k views

Output polygon data from postGIS and read it on Google Maps API

So, I have a group of polygons stored in PostGIS. I'm trying to build a web application with Google Base maps (using Google Maps API). Now, How do i output the polygons in the right format so that ...
6
votes
3answers
1k views

Join intersecting lines with PostGIS

This is something that I'm almost ashamed to ask but I can't seem to get it to work for the life of me. I have a road layer with segments, each segment has a Road ID and a segment type. I would like ...
6
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 ...
5
votes
2answers
471 views

What is the most common way of displaying geodata from Postgis on Leaflet?

For example, in my database I've some points with geographic coordinates. I want to display them on Leaflet JS layer. Which instruments should I use? Maybe there is some API...
5
votes
4answers
2k views

ST_Intersection slow query

I am trying to perform an intersection between two layers: Polyline layer representing some roads (~5500 rows) Polygon layer representing irregularly shaped buffers around various points of interest ...
4
votes
3answers
352 views

How to merge close points into polygon?

I have a set of coordinates (points & no overlaps) in a single table,each containing attribute number fields,like in the following image. I want to merge these points into smallest polygons by ...
14
votes
2answers
3k 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.
11
votes
3answers
530 views

How to add offsets to the route?

Edited: I want to ilustrate my question. Suppose that you're in "Point A" and want to go to "Point B". This points wouldn't be in "at_2po_4pgr" table cause aren't source/targets nodes. Then, I ...
11
votes
3answers
740 views

How to simplify a routable network?

I have a network graph that I need to simplify in the sense of reducing the number of edges. The idea would be to merge nodes that are located close together and remove the connecting short edges. ...
10
votes
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 ...
9
votes
2answers
2k views

How can I get a shapefile from a postgis query?

My data is in a PostGIS database. I would like to generate a shapefile from a query. How can I do that?