Re: request a new feature in fuzzystrmatch

Hi Atri,

Thanks for the quick response.

levenshtein edit distance defines operations of: insertion, deletion, modification.
Levenshtein-Damerau edit distance defines operations of:  insertion, deletion, modification
and transposition (
it will be two operations in levenshtein edit distance:
one deletion, and one insertion,
).

In spelling checker/corrector, i.e. levenshtein('cta', 'cat') will return 2.
but Levenshtein-Damerau('cta', 'cat') will return 1.
if the maximum error is 1, we can not get 'cat'.

In practice, Levenshtein-Damerau is more widely used than Levenshtein.
I believe you notice "Google automated search suggestions", they use 
Levenshtein-Damerau.

Thanks,

Liming


On 5/17/2013 3:00 AM, Atri Sharma wrote:
>
> Sent from my iPad
>
> On 17-May-2013, at 6:11, Liming Hu <dawninghu@gmail.com> wrote:
>
>> Hi,
>>
>> I am studying your levenshtein edit distance contribution in Postgresql.
>>
>> Can we add Levenshtein-Damerau edit distance since it is used in
>> spelling checker
>> instead of levenshtein edit distance?
>>
>> Levenshtein-Damerau edit distance C source code:
>>
http://stackoverflow.com/questions/10727174/dameraulevenshtein-distance-edit-distance-with-transposition-c-implementation.
>>
>>
>>
>>
> Could you give some use cases for the same, where the proposed feature does better than the current functionalities?
>
> Regards,
>
> Atri