mdouchin

The difference between XYZ and TMS tiles and how to convert between them

Lots of tile-based maps use either the XYZ or TMS scheme. These are the maps that have tiles ending in /0/0/0.png or something. Sometimes if it's a script, it'll look like &z=0&y=0&x=0 instead. Anyway, these are usually maps in Spherical Mercator.

Good examples are OpenStreetMap, Google Maps, MapBox, MapQuest, etc. Lots of maps.

Most of those are in XYZ. The best documentation for that is slippy map tilenames on the OSM Wiki, and Klokan's Tiles a la Google.

	WITH tab AS (
	SELECT
	a.attrelid::regclass::text AS t,
	a.attname AS c,
	pg_get_serial_sequence(a.attrelid::regclass::text, a.attname) AS s,
	nextval(pg_get_serial_sequence(a.attrelid::regclass::text, a.attname)) AS v
	FROM pg_attribute a
	JOIN pg_class c ON c.oid = a.attrelid
	WHERE
	a.attrelid::regclass::text LIKE '%'

	from datetime import datetime, timedelta
	import functools


	def timed_cache(**timedelta_kwargs):

	def _wrapper(f):
	update_delta = timedelta(**timedelta_kwargs)
	next_update = datetime.utcnow() + update_delta
	# Apply @lru_cache to f with no cache size limit


	- - PSQL script - - run as postgres - -

	drop table if exists bug2485move;
	drop sequence if exists bug2485move_seq;

	create sequence bug2485move_seq;

	select r_table_schema as schema, r_table_name as name, 'bug2485___'\|\|nextval('bug2485move_seq')::text as bug2485move into public.bug2485move from raster_columns;

	#!/bin/sh

	# To the extent possible under law, the person who associated CC0
	# with this work has waived all copyright and related or neighboring
	# rights to this work.
	# http://creativecommons.org/publicdomain/zero/1.0/

	SCRIPT_DIR=`dirname $0`

	if [ -e $1 ] ; then