Hi Karen,
I found a workable VBScript implementation as a function. This can be used during LOAD on record level. So you would need to join the source data first:
LOAD Script:
Levenshtein:
LOAD F1, F2, levenshtein(F1,F2) as distance;
LOAD * INLINE [
F1, F2
Qlik, Qlik ltd
Qlik ltd, Qlik Limited
Qlik Limited, QlikTech
Qlik, Klik
];
Module:
' Source:
' http://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Levenshtein_distance#VBScript
Function levenshtein( a, b )
Dim i,j,cost,d,min1,min2,min3
' Avoid calculations where there there are empty words
If Len( a ) = 0 Then levenshtein = Len( b 😞 Exit Function
If Len( b ) = 0 Then levenshtein = Len( a 😞 Exit Function
' Array initialization
ReDim d( Len( a ), Len( b ) )
For i = 0 To Len( a 😞 d( i, 0 ) = i: Next
For j = 0 To Len( b 😞 d( 0, j ) = j: Next
' Actual calculation
For i = 1 To Len( a )
For j = 1 To Len( b )
If Mid(a, i, 1) = Mid(b, j, 1) Then cost = 0 Else cost = 1 End If
' Since min() function is not a part of VBScript, we'll "emulate" it below
min1 = ( d( i - 1, j ) + 1 )
min2 = ( d( i, j - 1 ) + 1 )
min3 = ( d( i - 1, j - 1 ) + cost )
If min1 <= min2 And min1 <= min3 Then
d( i, j ) = min1
ElseIf min2 <= min1 And min2 <= min3 Then
d( i, j ) = min2
Else
d( i, j ) = min3
End If
Next
Next
levenshtein = d( Len( a ), Len( b ) )
End Function
Hope this helps..
- Ralf
Astrato.io Head of R&D
