Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP

Approximate String Matching library

branch: master
README.rdoc

amatch - Approximate Matching Extension for Ruby

Description

This is a collection of classes that can be used for Approximate matching, searching, and comparing of Strings. They implement algorithms that compute the Levenshtein edit distance, Sellers edit distance, the Hamming distance, the longest common subsequence length, the longest common substring length, the pair distance metric, the Jaro-Winkler metric.

Download

The latest version of amatch can be found at

Online Documentation should be located at

Installation

Just type into the command line as root:

# ruby install.rb

If you have installed rake (rake.rubyforge.org), you can also type:

# rake install

To install this extension as a gem type

# gem install amatch

Examples

require 'amatch'
# => true
include Amatch
# => Object

m = Sellers.new("pattern")
# => #<Amatch::Sellers:0x40366324>
m.match("pattren")
# => 2.0
m.substitution = m.insertion = 3
# => 3
m.match("pattren")
# => 4.0
m.reset_weights
# => #<Amatch::Sellers:0x40366324>
m.match(["pattren","parent"])
# => [2.0, 4.0]
m.search("abcpattrendef")
# => 2.0

m = Levenshtein.new("pattern")
# => #<Amatch::Levenshtein:0x4035919c>
m.match("pattren")
# => 2
m.search("abcpattrendef")
# => 2
"pattern language".levenshtein_similar("language of patterns")
# => 0.2

m = Hamming.new("pattern")
# => #<Amatch::Hamming:0x40350858>
m.match("pattren")
# => 2
"pattern language".hamming_similar("language of patterns")
# => 0.1

m = PairDistance.new("pattern")
# => #<Amatch::PairDistance:0x40349be8>
m.match("pattr en")
# => 0.545454545454545
m.match("pattr en", nil)
# => 0.461538461538462
m.match("pattr en", /t+/)
# => 0.285714285714286
"pattern language".pair_distance_similar("language of patterns")
# => 0.928571428571429

m = LongestSubsequence.new("pattern")
# => #<Amatch::LongestSubsequence:0x4033e900>
m.match("pattren")
# => 6
"pattern language".longest_subsequence_similar("language of patterns")
# => 0.4

m = LongestSubstring.new("pattern")
# => #<Amatch::LongestSubstring:0x403378d0>
m.match("pattren")
# => 4
"pattern language".longest_substring_similar("language of patterns")
# => 0.4

m = Jaro.new("pattern")
# => #<Amatch::Jaro:0x363b70>
m.match("paTTren")
# => 0.952380952380952
m.ignore_case = false
m.match("paTTren")
# => 0.742857142857143
"pattern language".jaro_similar("language of patterns")
# => 0.672222222222222

m = JaroWinkler.new("pattern")
# #<Amatch::JaroWinkler:0x3530b8>
m.match("paTTren")
# => 0.971428571712403
m.ignore_case = false
m.match("paTTren")
# => 0.79428571505206
m.scaling_factor = 0.05
m.match("pattren")
# => 0.961904762046678
"pattern language".jarowinkler_similar("language of patterns")
# => 0.672222222222222

Author

Florian Frank flori@ping.de

License

This is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License Version 2 as published by the Free Software Foundation: www.gnu.org/copyleft/gpl.html

Something went wrong with that request. Please try again.