I’m late to the game in posting this, but a few more links will help anyone arriving via Google when they’re looking for a Fuzzy-Match algorithm for Excel.

I wrote and implemented a fuzzy-logic VLookup function on a long flight a few years ago. The details are here:

http://excellerando.blogspot.com/2010/03/vlookup-with-fuzzy-matching-to-get.html

You are correct in placing the Levenshtein ‘edit distance’ algorithm at the top of the list: it is the gold standard for measuring similarity in passages of text… It is also somewhat ‘gold-plated’ in terms of weight and expense! A ‘sum-of-common-strings’ approach is perfectly adequate and well within the reach of VBA; So, after some work with modified Levenshtein algorithms – which one of your correspondents has linked to in a previous comment – I published a set of Match and Lookup functions using the Sum-of-common-strings approach.

There’s a discussion of the theoretical constraints in the previous post: please feel free to add the lessons you’ve learned the different approaches you came up with. I never got anything useful out of SoundEx for the complex lookups – addresses, especially – that we get in real-life applications.

http://chandoo.org/wp/2008/09/25/handling-spelling-mistakes-in-excel-fuzzy-search/

Thx,
JP

[VBA]
Function Str_Comp(st1 As String, st2 As String) As Double
‘
‘ returns a number showing % comparison between two names
‘
‘ i.e. =Str_Comp(A1, B1)
‘
‘ Format cell as Percentage to make it look pretty!!
‘
‘
Dim MtchTbl(100, 100)
Dim MyMax As Double, ThisMax As Double
Dim i As Integer, j As Integer, ii As Integer, jj As Integer

With WorksheetFunction
st1$ = Trim$(.Proper(st1$))
st2$ = Trim$(.Proper(st2$))
End With

MyMax# = 0

For i% = Len(st1$) To 1 Step -1
For j% = Len(st2$) To 1 Step -1
If Mid$(st1$, i%, 1) = Mid$(st2$, j%, 1) Then
ThisMax# = 0
For ii% = (i% + 1) To Len(st1$)
For jj% = (j% + 1) To Len(st2$)
If MtchTbl(ii%, jj%) > ThisMax# Then
ThisMax# = MtchTbl(ii%, jj%)
End If
Next jj%
Next ii%
MtchTbl(i%, j%) = ThisMax# + 1
If (ThisMax# + 1) > ThisMax# Then
MyMax# = ThisMax# + 1
End If
End If
Next j%
Next i%
Str_Comp = MyMax# / ((Len(st1$) + Len(st2$)) / 2)

End Function
[/VBA]

And here’s another link to fuzzy lookup code:

http://hairyears.livejournal.com/115867.html

http://www.dailydoseofexcel.com/archives/2004/06/16/fuzzy-text-match/

I also have a UDF somewhere (can’t locate it at the moment) that returns a percentage indicating how close two words are to each other.

–JP

By the way, congrats on being blocked by Websense. You’ve made the exclusive club!