CTK Exchange
Front Page
Movie shortcuts
Personal info
Awards
Reciprocal links
Terms of use
Privacy Policy

Interactive Activities

Cut The Knot!
MSET99 Talk
Games & Puzzles
Arithmetic/Algebra
Geometry
Probability
Eye Opener
Analog Gadgets
Inventor's Paradox
Did you know?...
Proofs
Math as Language
Things Impossible
My Logo
Math Poll
Other Math sit's
Guest book
News sit's

Recommend this site

Manifesto: what CTK is about Search CTK Buying a book is a commitment to learning Table of content Things you can find on CTK Chronology of updates Email to Cut The Knot Recommend this page

CTK Exchange

Subject: "Levenshtein Distance"     Previous Topic | Next Topic
Printer-friendly copy     Email this topic to a friend    
Conferences The CTK Exchange College math Topic #404
Reading Topic #404
Jon
guest
Dec-01-03, 03:05 PM (EST)
 
"Levenshtein Distance"
 
   Hi, I'm taking a look at Levenshtein distance for comparing two strings, and was wondering if (and how!) we can prove that it'satisfies the triangle inequality?

Many thanks from a lost computing student!

Jon


  Alert | IP Printer-friendly page | Reply | Reply With Quote | Top
Vladimir
Member since Jun-22-03
Dec-01-03, 08:08 PM (EST)
Click to EMail Vladimir Click to view user profileClick to add this user to your buddy list  
1. "RE: Levenstein Distance"
In response to message #0
 
   LAST EDITED ON Dec-01-03 AT 08:24 PM (EST)
 
Levenstein distance of 2 finite sequences (such as strings, DNA sequences, protein amino acid sequences, etc.) is defined as the minimum number of steps (replacement, deletion, or insertion) required to edit one string into the other.

Let A, B, C be 3 arbitrary strings and let D(A,B) be Levenstein distance of strings A and B.

1. D(A,A) = 0
No editing is required.

2. D(A,B) = D(B,A)
Minimum number of steps required to edit'string A into string B is the same as the minimum number of steps reqiured to edit string B into string A in reverse.

3. D(A,C) <= D(A,B) + D(B,C)
String A can be edited to string C directly. Or it can be first edited to some other string B, which is subsequently edited to string C. This cannot take less editing steps than the minimum number of steps required for direct editing.

Hence, Levenstein distance is a metric. See Alignment: Definitions and Algorithms.


  Alert | IP Printer-friendly page | Reply | Reply With Quote | Top
Prerana
guest
May-27-06, 10:47 AM (EST)
 
3. "RE: Levenshtein Distance"
In response to message #0
 
   Hej,

Well I am a computer scientist and planning to work on Levenshtein distance and the reversal distances. Do you have any idea about the recent work done in this very field? My email is prda4740@student.uu.se.
Please reply me.


/Prerana



  Alert | IP Printer-friendly page | Reply | Reply With Quote | Top
alexbadmin
Charter Member
1852 posts
May-29-06, 10:31 AM (EST)
Click to EMail alexb Click to send private message to alexb Click to view user profileClick to add this user to your buddy list  
4. "RE: Levenshtein Distance"
In response to message #3
 
   >Well I am a computer scientist

... which I am not

>and planning to work on
>Levenshtein distance and the reversal distances.

Good luck. Please keep us informed of any progress.

>Do you have
>any idea about the recent work done in this very field?

Candidly, no. But googling brought up many links I was unaware of.


  Alert | IP Printer-friendly page | Reply | Reply With Quote | Top
Pierre Charland
Member since Dec-22-05
Jun-12-06, 10:15 AM (EST)
Click to EMail Pierre%20Charland Click to send private message to Pierre%20Charland Click to view user profileClick to add this user to your buddy list  
5. "RE: Levenshtein Distance"
In response to message #0
 
   Nice applets for <string comparison> at
https://www-igm.univ-mlv.fr/~lecroq/seqcomp/index.html
and
https://odur.let.rug.nl/~kleiweg/lev/

Algorithm's code in Java, C++, VBasic at
https://www.merriampark.com/ld.htm

AlphaChapMtl


  Alert | IP Printer-friendly page | Reply | Reply With Quote | Top
alexbadmin
Charter Member
1852 posts
Jun-12-06, 10:23 AM (EST)
Click to EMail alexb Click to send private message to alexb Click to view user profileClick to add this user to your buddy list  
6. "RE: Levenshtein Distance"
In response to message #5
 
   Many thanks. Very good links.


  Alert | IP Printer-friendly page | Reply | Reply With Quote | Top

Conferences | Forums | Topics | Previous Topic | Next Topic

You may be curious to have a look at the old CTK Exchange archive.
Please do not post there.

Copyright © 1996-2018 Alexander Bogomolny

Search:
Keywords:

Google
Web CTK