soundex(3tcl) [debian man page]
soundex(3tcl) Soundex soundex(3tcl) __________________________________________________________________________________________________________________________________________________ NAME
soundex - Soundex SYNOPSIS
package require Tcl 8.2 package require soundex ?1.0? ::soundex::knuth string _________________________________________________________________ DESCRIPTION
This package provides soundex algorithms which allow the comparison of words based on their phonetic likeness. Currently only an algorithm by Knuth is provided, which is tuned to english names and words. ::soundex::knuth string Computes the soundex code of the input string using Knuth's algorithm and returns it as the result of the command. EXAMPLES
% ::soundex::knuth Knuth K530 BUGS, IDEAS, FEEDBACK This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category soundex of the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883]. Please also report any ideas for enhancements you may have for either package and/or documentation. KEYWORDS
knuth, soundex, text comparison, text likeness CATEGORY
Hashes, checksums, and encryption COPYRIGHT
Copyright (c) ????, Algorithm: Donald E. Knuth Copyright (c) 2003, Documentation: Andreas Kupries <andreas_kupries@users.sourceforge.net> Copyright (c) 1998, Tcl port: Evan Rempel <erempel@uvic.ca> soundex 1.0 soundex(3tcl)
Check Out this Related Man Page
Text::Soundex(3pm) Perl Programmers Reference Guide Text::Soundex(3pm) NAME
Text::Soundex - Implementation of the Soundex Algorithm as Described by Knuth SYNOPSIS
use Text::Soundex; $code = soundex $string; # get soundex code for a string @codes = soundex @list; # get list of codes for list of strings # set value to be returned for strings without soundex code $soundex_nocode = 'Z000'; DESCRIPTION
This module implements the soundex algorithm as described by Donald Knuth in Volume 3 of The Art of Computer Programming. The algorithm is intended to hash words (in particular surnames) into a small space using a simple model which approximates the sound of the word when spo- ken by an English speaker. Each word is reduced to a four character string, the first character being an upper case letter and the remain- ing three being digits. If there is no soundex code representation for a string then the value of $soundex_nocode is returned. This is initially set to "undef", but many people seem to prefer an unlikely value like "Z000" (how unlikely this is depends on the data set being dealt with.) Any value can be assigned to $soundex_nocode. In scalar context "soundex" returns the soundex code of its first argument, and in list context a list is returned in which each element is the soundex code for the corresponding argument passed to "soundex" e.g. @codes = soundex qw(Mike Stok); leaves @codes containing "('M200', 'S320')". EXAMPLES
Knuth's examples of various names and the soundex codes they map to are listed below: Euler, Ellery -> E460 Gauss, Ghosh -> G200 Hilbert, Heilbronn -> H416 Knuth, Kant -> K530 Lloyd, Ladd -> L300 Lukasiewicz, Lissajous -> L222 so: $code = soundex 'Knuth'; # $code contains 'K530' @list = soundex qw(Lloyd Gauss); # @list contains 'L300', 'G200' LIMITATIONS
As the soundex algorithm was originally used a long time ago in the US it considers only the English alphabet and pronunciation. As it is mapping a large space (arbitrary length strings) onto a small space (single letter plus 3 digits) no inference can be made about the similarity of two strings which end up with the same soundex code. For example, both "Hilbert" and "Heilbronn" end up with a soundex code of "H416". AUTHOR
This code was implemented by Mike Stok ("stok@cybercom.net") from the description given by Knuth. Ian Phillipps ("ian@pipex.net") and Rich Pinder ("rpinder@hsc.usc.edu") supplied ideas and spotted mistakes. perl v5.8.0 2002-06-01 Text::Soundex(3pm)