[AccessD] Fuzzy Matching (Like Soundex) or other ideas?

[Ryan W]

Thanks! I'll see what I can do with this on Monday.



On Sat, Apr 22, 2023 at 12:41 AM Stuart McLachlan <stuart at lexacorp.com.pg>
wrote:

> On 22 Apr 2023 at 15:25, Stuart McLachlan wrote:
>
> > Oops, it's a long time since I did it.
> >
> > If the strings are different lengths, it's the levenshtein distance :)
> >
> >
> Or you could go a step further with Damerau-Levenshtein distance
> https://en.wikipedia.org/wiki/Damerau%E2%80%93Levenshtein_distance
>
> (The Damerau-Levenshtein distance differs from the classical Levenshtein
> distance
> by including transpositions among its allowable operations in addition to
> the three
> classical single-character edit operations (insertions, deletions and
> substitutions) )
>
>
> But for plain Lenenschtein, Here's some very old PB code, it should be
> trivial to adapt to VBA
>
> FUNCTION fn_LevenshteinDistance( BYVAL strText1 AS STRING, BYVAL strText2
> AS
> STRING, OPT lngCaseMatters AS LONG ) AS LONG
>   LOCAL lngText1Idx   AS LONG
>   LOCAL lngText1Len   AS LONG
>   LOCAL lngText2Idx   AS LONG
>   LOCAL lngText2Len   AS LONG
>   LOCAL pbytText1Char AS BYTE PTR
>   LOCAL pbytText2Char AS BYTE PTR
>   lngText1Len = LEN( strText1 )
>   lngText2Len = LEN( strText2 )
>   IF ( lngText1Len = 0 ) OR ( lngText2Len = 0 ) THEN FUNCTION = MAX%(
> lngText1Len,
> lngText2Len ) : EXIT FUNCTION
>   IF ISFALSE( ISMISSING( lngCaseMatters )) AND ISFALSE( lngCaseMatters )
> THEN
>     strText1 = UCASE$( strText1 )
>     strText2 = UCASE$( strText2 )
>   END IF
>   DIM lngMatrix( lngText1Len, lngText2Len ) AS LONG
>   FOR lngText1Idx = 0 TO lngText1Len
>     lngMatrix( lngText1Idx, 0 ) = lngText1Idx
>   NEXT lngText1Idx
>   FOR lngText2Idx = 0 TO lngText2Len
>     lngMatrix( 0, lngText2Idx ) = lngText2Idx
>   NEXT lngText2Idx
>   pbytText1Char = STRPTR( strText1 )
>   pbytText2Char = STRPTR( strText2 )
>   FOR lngText1Idx = 1 TO lngText1Len
>     FOR lngText2Idx = 1 TO lngText2Len
>       lngMatrix( lngText1Idx, lngText2Idx ) = _
>         MIN%( lngMatrix( lngText1Idx - 1, lngText2Idx     ) + 1, _
>           lngMatrix( lngText1Idx,     lngText2Idx - 1 ) + 1, _
>           lngMatrix( lngText1Idx - 1, lngText2Idx - 1 ) + _
>           ABS( @pbytText1Char[ lngText1Idx - 1 ] <> @pbytText2Char[
> lngText2Idx - 1 ] ))
>     NEXT lngText2Idx
>   NEXT lngText1Idx
>   FUNCTION = lngMatrix( lngText1Len, lngText2Len )
> END FUNCTION
>
>
>
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