Are there any Fuzzy Search or String Similarity Functions libraries written for C#?

Question

There are similar question, but not regarding C# libraries I can use in my source code.

Thank you all for your help.

I've already saw lucene, but I need something more easy to search for similar strings and without the overhead of the indexing part.

The answer I marked has got two very easy algorithms, and one uses LINQ too, so it's perfect.

Answer 1

The Beagle Project for Linux is written in c# (mono) and is a google-desktop like search tool. It may have some code in there for these kind of string matching.

If I recall correctly, it uses the Lucene library for searching and retrieving data. Maybe that can be useful for your project too.

Answer 2

Have you taken a look at Lucene.net? It is a port of the Java Lucene search engine API to the .Net platform. That library offers a lot of search functionality. I played around with it a year or so ago, so don't take my suggestion as based on tons of experience. I saw it in the book Windows Developer Power Tools and took it for a test drive. You might look through their API documentation to see if it offers something like the Fuzzy Search for which you are looking.

Answer 3

This code project paper has a string similarity function using the Levenshtein distance.

Answer 4

There is the following Levenshtein Distance Algorithm which assigns a value to the similarity of two strings (well, the difference actually), that could be used to build upon: http://www.merriampark.com/ldcsharp.htm.

Answer 5

Levenshtein distance implementation:

• Using LINQ (not really, see comments)
• Not using LINQ

I have a .NET 1.1 project in which I use the latter. It's simplistic, but works perfectly for what I need. From what I remember it needed a bit of tweaking, but nothing that wasn't obvious.

Answer 6

Hello,

I have used "Ternary Search Tree Dictionary in C#" (http://www.codeproject.com/KB/recipes/tst.aspx) to search for similar strings.

Regards, Patricio

Answer 7

you can also look at the very impressive library titled Sam's String Metrics http://www.dcs.shef.ac.uk/~sam/stringmetrics.html. this includes a host of algorithms.

• Hamming distance
• Levenshtein distance
• Needleman-Wunch distance or Sellers Algorithm
• Smith-Waterman distance
• Gotoh Distance or Smith-Waterman-Gotoh distance
• Block distance or L1 distance or City block distance
• Monge Elkan distance
• Jaro distance metric
• Jaro Winkler
• SoundEx distance metric
• Matching Coefficient
• Dice’s Coefficient
• Jaccard Similarity or Jaccard Coefficient or Tanimoto coefficient
• Overlap Coefficient
• Euclidean distance or L2 distance
• Cosine similarity
• Variational distance
• Hellinger distance or Bhattacharyya distance
• Information Radius (Jensen-Shannon divergence)
• Harmonic Mean
• Skew divergence
• Confusion Probability
• Tau
• Fellegi and Sunters (SFS) metric
• TFIDF or TF/IDF
• FastA
• BlastP
• Maximal matches
• q-gram
• Ukkonen Algorithms