--- /dev/null
+<?xml version="1.0" encoding="UTF-8"?>
+
+ <sect1 id="Tiger_Geocoder">
+ <title>Tiger Geocoder</title>
+ <sect1info>
+ <abstract>
+ <para>A plpgsql based geocoder written for <ulink url="http://www.census.gov/geo/www/tiger/index.html">TIGER census data</ulink>.</para>
+ <para>Design:</para>
+ <para>There are two components to the geocoder, the address normalizer and the address geocoder. </para>
+ <para>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 and rating reflecting the location of the given address.</para>
+ <para>The geocoder should be simple for anyone familiar with PostGIS to install and use.</para>
+ <para>It should be robust enough to function properly despite formatting and spelling errors.</para>
+ <para>It should be extensible enough to be used with future data updates, or alternate data sources with a minimum of coding changes.</para>
+ </abstract>
+ </sect1info>
+
+ <refentry id="Geocode">
+ <refnamediv>
+ <refname>Geocode</refname>
+
+ <refpurpose>Takes in an address as a string and outputs a set of possible locations which include a point geometry in NAD 83 long lat, a normalized address for each, and the rating. The lower the rating the more likely the match.
+ Results are sorted by lowest rating first.</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>setof record<function>geocode</function></funcdef>
+ <paramdef><type>address </type> <parameter>varchar</parameter></paramdef>
+ <paramdef><type>OUT addy</type> <parameter>norm_addy</parameter></paramdef>
+ <paramdef><type>OUT geomout</type> <parameter>geometry</parameter></paramdef>
+ <paramdef><type>OUT rating</type> <parameter>integer</parameter></paramdef>
+ </funcprototype>
+ <funcprototype>
+ <funcdef>setof record<function>geocode</function></funcdef>
+ <paramdef><type>in_addy </type> <parameter>norm_addy</parameter></paramdef>
+ <paramdef><type>OUT addy</type> <parameter>norm_addy</parameter></paramdef>
+ <paramdef><type>OUT geomout</type> <parameter>geometry</parameter></paramdef>
+ <paramdef><type>OUT rating</type> <parameter>integer</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsection>
+ <title>Description</title>
+
+ <para>Takes in an address as a string and outputs a set of possible locations which include a point geometry in NAD 83 long lat, a <varname>normalized_address</varname> (addy) for each, and the rating. The lower the rating the more likely the match.
+ Results are sorted by lowest rating first. The higher the rating the less likely the geocode is right.</para>
+
+ <para>Enhanced: 2.0.0 to support Tiger 2010 structured data and revised some logic to improve speed.</para>
+
+
+ </refsection>
+
+
+ <refsection>
+ <title>Examples</title>
+ <para>Exact matches are fairly fast (205ms)</para>
+ <programlisting>SELECT g.rating, ST_X(g.geomout) As lon, ST_Y(g.geomout) As lat, (addy).address As stno, (addy).streetname As street,
+ (addy).streettypeabbrev As styp, (addy).location As city, (addy).stateabbrev As st,(addy).zip
+ FROM geocode('75 State Street, Boston MA 02109') As g;
+ rating | lon | lat | stno | street | styp | city |st | zip
+ --------+-------------------+------------------+------+--------+------+--------+----+-------
+ 0 | -71.0556974285714 | 42.3590795714286 | 75 | State | St | Boston | MA | 02109
+</programlisting>
+ <para>Even if zip is not passed in the geocoder can guess (took about 450 ms)</para>
+ <programlisting>SELECT g.rating, ST_AsText(ST_SnapToGrid(g.geomout,0.00001)) As wktlonlat, (addy).address As stno, (addy).streetname As street,
+ (addy).streettypeabbrev As styp, (addy).location As city, (addy).stateabbrev As st,(addy).zip
+ FROM geocode('226 Hanover Street, Boston, MA') As g;
+ rating | wktlonlat | stno | street | styp | city | st | zip
+--------+---------------------------+------+---------+------+--------+----+-------
+ 0 | POINT(-71.05518 42.36311) | 226 | Hanover | St | Boston | MA | 02113
+</programlisting>
+<para>Can handle misspellings and provides more than one possible solution with rankings and takes longer (4 seconds).</para>
+<programlisting>SELECT g.rating, ST_AsText(ST_SnapToGrid(g.geomout,0.00001)) As wktlonlat, (addy).address As stno, (addy).streetname As street,
+ (addy).streettypeabbrev As styp, (addy).location As city, (addy).stateabbrev As st,(addy).zip
+ FROM geocode('31 - 37 Stewart Street, Boston, MA 02116') As g;
+ rating | wktlonlat | stno | street | styp | city | st| zip
+--------+---------------------------+------+---------+------+---------------+----+-------
+ 55 | POINT(-71.36934 42.68158) | 31 | Stewart | St | Lowell | MA | 01826
+ 55 | POINT(-71.34825 42.63324) | 31 | Stewart | St | Lowell | MA | 01851
+ 55 | POINT(-71.59109 42.22556) | 31 | Stewart | St | Hopkinton | MA | 01748
+ 56 | POINT(-71.26747 42.54075) | 31 | Stewart | St | Burlington | MA | 01821
+ 56 | POINT(-71.20324 42.53543) | 31 | Stewart | St | Burlington | MA | 01803
+ 57 | POINT(-72.57319 42.22111) | 31 | Stewart | St | Chicopee | MA | 01075
+ 57 | POINT(-72.59728 42.16919) | 31 | Stewart | St | Chicopee | MA | 01020
+ 59 | POINT(-71.08627 42.78109) | 31 | Stewart | St | Haverhill | MA | 01830
+ 60 | POINT(-71.36752 42.09772) | 31 | Stewart | St | Franklin Town | MA | 02038
+ 60 | POINT(-71.14573 41.72036) | 31 | Stewart | St | Fall River | MA | 02720
+ 70 | POINT(-71.0646 42.35105) | 31 | Stuart | St | Boston | MA | 02116
+(11 rows) </programlisting>
+
+ </refsection>
+
+ <!-- Optionally add a "See Also" section -->
+ <refsection>
+ <title>See Also</title>
+ <para><xref linkend="ST_AsText"/>,<xref linkend="ST_SnapToGrid"/>, <xref linkend="ST_X"/>, <xref linkend="ST_Y"/></para>
+ </refsection>
+ </refentry>
+
+ </sect1>
projects / postgis / commitdiff