postgis/extras/tiger_geocoder

$Id$
TIGER Geocoder

  2011/01/23

  A plpgsql based geocoder written for TIGER census data.

Design:

There are two components to the geocoder, the address normalizer and the
address geocoder.  These two components are described separately.

The goal of this project is to build a fully functional geocoder that can 
process an arbitrary address string and, using normalized TIGER census data,
produce a point geometry reflecting the location of the given address.

- The geocoder should be simple for anyone familiar with PostGIS to install
  and use.
- It should be robust enough to function properly despite formatting and 
  spelling errors.
- It should be extensible enough to be used with future data updates, or
  alternate data sources with a minimum of coding changes.

Installation:

	Refer to the README in the respective year tiger folder for installation and example usage.  The latest scripts as of this writing are for tiger_2010.
	

Usage:

	SELECT g.rating, g.geomout, (addy).* FROM geocode('address string') As g;
	
e.g: SELECT g.rating, 
	ST_X(geomout) As lon, 
	ST_Y(geomout) As lat, (addy).*  FROM geocode('1731 New Hampshire Avenue Northwest, Washington, DC 20010') As g;

Notes:

- The assumed format for the address is the US Postal Service standard:
  () indicates a field required by the geocoder, [] indicates an optional field.

	(address) [dirPrefix] (streetName) [streetType] [dirSuffix]
	[internalAddress] [location] [state] [zipCode]



Address Normalizer:

The goal of the address normalizer is to provide a robust function to break a
given address string down into the components of an address.  While the
normalizer is built specifically for the normalized US TIGER Census data,  it
has been designed to be reasonably extensible to other data sets and localities.

Usage:

	normalize_address('address string');
	
	e.g.: SELECT naddy.* FROM normalize_address('29645 7th Street SW Federal Way 98023') AS naddy;
	
	 address | predirabbrev |      streetname       | streettypeabbrev | postdirabbrev | internal | location | stateabbrev |  zip  | parsed
	 ---------+-------------+-----------------------+------------------+---------------+----------+----------+-------------+-------+--------
     29645 |               | 7th Street SW Federal  | Way              |               |          |          |             | 98023 |