Django is a high-level Python Web framework that encourages rapid development and clean, pragmatic design.

learn more… | top users | synonyms

5
votes
4answers
3k views

Geodjango- get the distance between 2 points

Sorry to be asking yet another geodjango newbie question. What I want to do is quite simple, I have 2 locations defined by gps coords, lat / long like returned by google maps: ...
7
votes
1answer
368 views

What are some good resources related to Geodjango?

I am trying to learn Geodjango. Has anyone used it in their own project? The documentation on the official site is sparse. Can someone point out the best resources helpful in learning it other than ...
-1
votes
1answer
128 views

GeoPortal Managing Tool [closed]

i know in this site everybody more or less have been setup a geoportal for showing their basemaps and analysis on local or net for their workers or conserned people in the net. it is obvious that in ...
5
votes
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 ...
1
vote
1answer
212 views

GeoDjango 'NoneType' error when using 'distance' function

I have a site that's working on our staging server but after copying it to the live server I am getting the following error when trying to perform a distance() call (code cut down to minimum) ...
3
votes
2answers
456 views

How to fix this spatial query in GeoDjango?

I am new to Geodjango. and I am following the steps given in https://docs.djangoproject.com/en/dev/ref/contrib/gis/tutorial/# and the steps i followed before ...
1
vote
0answers
245 views

How to Modify Polygons in GeoDjango?

Just getting acquainted with GeoDjango. Have Basic Tutorial app created with sample world data. In trying out the admin, I appreciate seeing the polygon on the map and a couple basic tools for adding ...
4
votes
3answers
293 views

How to import an Access database to GeoDjango?

I'm a I've just inherited a pile of institutional geodata that's stored in an MS Access database. I need to pull that data out into a format that I can work with in GeoDjango--so I'm OK with ...
1
vote
1answer
195 views

Best way to exclude 0,0 from geography results (PostGIS, GeoDjango)

Using PostGis and GeoDjango with a model having a Geography field I'm trying to exclude results where the location is 0,0. I get the error PostGIS geography does not support the "exact" lookup. The ...
5
votes
1answer
855 views

Geodjango distance between two points appears incorrect

I want to show you something. I am using django+postgis and I am experiencing wrong distance values between two points. This is my model: class Location(models.Model): name = ...
2
votes
1answer
1k views

Using a geodjango PointField with geography=True, my distance calculations are wrong

Here's my model: class ExchangeArea(models.Model): """ An Exchange Service Area, calculated from a phone exchange and surrounding census tracts. """ coordinates = ...
4
votes
1answer
3k views

Why is PostGIS query not using spatial index?

I am having an issue with a spatial query that is not making use of indexes. My schema is: CREATE TABLE geoplanet_place ( woeid integer NOT NULL, "name" character varying(300) NOT NULL, ...
2
votes
1answer
563 views

How do I query for all polygons within a distance from a point?

Call me stupid, but somehow I couldn't figure out how to do the following. I've got a testing shapefile with 18 features, which I successfully imported into GeoDjango (1.3, running on Spatialite). As ...
6
votes
3answers
1k views

Can Polygons be generalized to MultiPolygons in GeoDjango?

I set up a model with models.PolygonField in geodjango, using postgres as database. I try to import shp into postgres. The problem is, shp (compiled with QGIS) mixes polygon and multipolygon, hence it ...
6
votes
2answers
885 views

Generating GeoJSON tiles from GeoDjango - basic overview?

I'm working with the glorious PolyMaps and I want to build a map similar to the population example. I understand that this needs GeoJSON tiles. I have a GeoDjango database, with a bunch of County ...
3
votes
1answer
272 views

How to mix coordinate systems in GeoDjango?

This is a beginner question about working with different coordinate systems in GeoDjango. I've got a GeoDjango object with a polygon field, stored as OSGB coordinates: class Region(models.Model): ...
1
vote
1answer
582 views

How to segmentize/sample a LineString using geodjango (postgis/geos) and/or openlayers?

I'm trying to sample points along a linestring. The goal is to have the distance between 2 consecutive points to be at most X (eg. 50m). I'm drawing linestring in openlayers and sending it to a ...
7
votes
3answers
1k views

Use Esri Geoservices REST as backend for Python web framework (Django?)

I would like to know if it's feasible to use an existing Python web framework such as Django/GeoDjango as a frontend to work with Esri's Geoservices REST API? I envision developing a database engine ...
3
votes
2answers
540 views

PostGIS + pgRouting: Adding dummy links to a road network and performing routing analysis

I'm a beginner when it comes to postgis and pgrouting development. For a project I'm working on and a bit of the algorithm: I have a polygon layer that represents zones I have a line layer that ...
7
votes
1answer
208 views

Optimize GEOSGeometry's spatial operations by avoiding thread-safety checks

A ranking algorithm I'm developing for a Django webapp requires performing spatial operations (within, intersections, sym_difference, etc.) using a query against large number of geometry objects. ...
2
votes
2answers
1k views

Is it possible to do server-side (WMS) rendering / caching of vector data

I have to develop a webapp that will have to display a large number of polygons on a webpage, with complex filtering options. The source data never changes (I will simply reload a new version of the ...
2
votes
1answer
840 views

Area units for GEOS area property?

I'm working with GeoDjango and have a polygon in the WGS84 projection. I need to find its area in square meters. When I call polygon.area, I get some float out and I have no idea what the units of ...
1
vote
2answers
660 views

PostGIS - certain MultiPolygons cause “BOOM! Could not generate outside point!”

I've just posted this at StackOverflow and someone suggested I try here. Original: http://stackoverflow.com/q/5863859/246265 I'm trying to represent a rectangular area which crosses 180 degrees ...
6
votes
1answer
384 views

Is there a GeoDjango tutorial for GeoRSSFeeds?

I'm going through GeoDjango basics right now. Ideally, I'd like to publish a GeoRSS from a set of data I have that is already in Django's database. I know how to get a regular Feed working, but when I ...
5
votes
1answer
904 views

Best GeoDjango MySQL workaround for distance queries

I'm using mysql 5.1.50, so the distance QuerySet method is not available to me. Here is my model: class Location(models.Model): name = models.CharField(max_length='100') point = ...
4
votes
1answer
670 views

GeoDjango: Order by distance for model that has a ForeignKey relation to another model that has a PointField

Model A has a ForeignKey relation to Model B. Model B has a PointField. Is there a way to order Model A objects by distance from a POINT?
4
votes
1answer
330 views

Monster Spatial database server suggestions

I'm going to setup a open Mapserver w/ Openlayers, Geojango, Postgis using Postgresql. And I need some suggestions from people that have been shopping for what I need longer than I have. What would ...
4
votes
1answer
1k views

GeoDjango: order PointField by distance?

I've got a GeoDjango model as follows: class City(models.Model): id = models.IntegerField(primary_key=True) county = models.ForeignKey(County) location = models.PointField(null=True, ...
5
votes
2answers
1k views

Django PolygonField: how to display on map?

Extremely beginner question. I have a GeoDjango model with a MultiPolygonField. How do I retrieve the value of this field and display it as a polygon on a map? class county(models.Model): cd = ...
4
votes
1answer
445 views

Geodjango insert statement: psycopg2.IntegrityError: violates check constraint

Why is the following INSERT statement throwing this error? INSERT INTO domes_place (placeid, structidx, oscode) VALUES ('10', '1', 'POINT(51.121282945772 1.3138398501222)'); psycopg2.IntegrityError: ...
2
votes
2answers
1k views

Error adding data to Geodjango database: parse error… within geometry

I'm trying to insert some values into a Geodjango database, but getting errors. This is the table: class Place(models.Model): placeid = models.IntegerField(primary_key=True) structidx = ...
2
votes
3answers
318 views

UK National Grid references and GeoDjango

Newbie question. I'm trying to insert some UK National Grid references into a Django PointField defined as follows: oscode = models.PointField(srid=27700, null=True, blank=True) My question is ...
6
votes
1answer
613 views

Help simplifying multipolygons in geodjango

I have a few multipolygons that have several hundred points in them. I'm looking to create less complex "thumbnails" polygons. Naturally I'm attempting to use the simplify method, which is supposed ...
2
votes
4answers
4k views

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 ...
5
votes
5answers
745 views

Getting a square mile bounding box anchored by coordinates?

Let's say I have a lat/lng coordinate pair. I want to determine the coordinates that would create a square mile box. The existing coordintae pair would be the top left of the box, and the coordinate ...