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Find nearest-matching string from a set

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Find nearest-matching string from a set

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04 Jun 2012 (Updated )

Computes shortest distance between a key string and a set of strings to find the nearest match.

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Description

Uses a modified Vagner-Fischer algorithm to find the Levenshtein distance between each pair of strings. Progressively narrows the threshold to equal the distance of the best match found so far, reducing run time.

Updated to correct the algorithm. (sorry!)

Optional behaviors include an upper-bound threshold distance, detect first or multiple matches of equal distance, case insensitivity.

Examples:

>> [i,d]=strnearest({'first string'},{'string 2','abcdefgh','FURSrtd','firststring'})

i =

    [4]

d =

     2

>> [i,d]=strnearest({'1','first string'},{'string 2','abcdefgh','1st string','FURSrtd','seconaaad string','2'})

i =

    [6] [3]

d =

     1 5

>>

Acknowledgements

Calculation Of Distance Between Strings inspired this file.

Required Products MATLAB
MATLAB release MATLAB 7.13 (R2011b)
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Comments and Ratings (5)
03 May 2014 Yung-Yeh

Oh...I see

It's actually the Levenshtein distance. The title "nearest-matching string" really confuses me.

03 May 2014 Yung-Yeh

This is weird, I tried

[x,d] = strnearest('ABC',{'""','"ABC"'})

but it return
x = [1 2]
d = 3

16 Aug 2013 Brandon Kuczenski

apologies- I have uploaded a corrected submission.

@@ -98,13 +98,16 @@
else
bb=list{T};
end
- luma=numel(key); lima=numel(bb);
- dl=dist*ones([luma+1,lima+1]);
- dl(1,:)=0:lima; dl(:,1)=0:luma;
+ eql=char({key;bb}); % equal length
+ keyy=eql(1,:); % space-padded key
+ bb=eql(2,:); % space-padded candidate
+ luma=numel(keyy);
+ dl=dist*ones([luma+1,luma+1]);
+ dl(1,:)=0:luma; dl(:,1)=0:luma;
%Distance
for i=1:luma
- for j=max([1,i-dist]):min([lima,i+dist])
- kr=krk*(~(key(j)==bb(i)));
+ for j=max([1,i-dist]):min([luma,i+dist])
+ kr=krk*(~(keyy(min([j luma]))==bb(i)));
dl(i+1,j+1)=min([dl(i,j)+kr,dl(i,j+1)+1,dl(i+1,j)+1]);
end
end

16 Aug 2013 lala

Still no working example? :)

10 Sep 2012 Sven

Was this tested?

>> [index,distance] = strnearest({'first string'},{'string 2'})

index =

[1]

distance =

0

Perhaps a working example would be useful.

Updates
26 Jun 2012

Add link to strdist.m

19 Aug 2013

Updated to correct an error in the code and to add working examples to the description.

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