Code


Version 13 (modified by Jeremy Dunck <jdunck@…>, 7 years ago) (diff)

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The gis branch intends to add a contrib app implementing geographic support.

What's GIS?

  • 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).

Useful code

Questions

Alternatives

Implementation

Phase 1

Assume existing data and fields, and that the

Custom Manager

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 Types

Field type for a geometry

GIS wrapper

wrapper for geos, have the ability to do something like

from django.contrib.gis import area
area(bbox.geom)