|Version 13 (modified by Jeremy Dunck <jdunck@…>, 7 years ago) (diff)|
The gis branch intends to add a contrib app implementing geographic support.
- Series of blog posts giving intro to GIS; choice quote from an early post: "If you feel like ending a conversation with a developer then simply bring up the topic of character encodings ... [o]r ... coordinate systems. ... So in the spirit of Tim Bray's and Joel Spolsky's wonderful writeups of character encodings, I thought I'd put together a basic survival guide to coordinate systems over my next few posts and then tie it back to Google Maps."
- More on map projections, including why people can't agree on just one (utf-8).
- PostGIS, the OpenGIS SQL Types (pdf) implementation for Postgresql
- GEOS, low-level C++ port of Jave Topology Suite, used by PostGIS
- Geopy calcs distances using (very accurate) Vincenty, and uses the WGS 84 datum.
Assume existing data and fields, and that the
A custom manager (and queryset) to support lookups like:
Schools.objects.filter(geom__overlaps=bbox.geom) # && Schools.objects.filter(geom__contains=bbox.geom) # ~ Schools.objects.filter(geom__sameas=bbox.geom) # ~= Schools.objects.filter(geom__inside=bbox.geom) # @
Field type for a geometry
wrapper for geos, have the ability to do something like
from django.contrib.gis import area area(bbox.geom)