string similarity comparison

I'm looking for a method to compare two strings and grade them for
similarity.

My idea is to strip out common words and punctuation and create a checksum
of each remaining string. I would then compare the checksums and if they are
close then there's a potential match (to be judged by user interaction.)

Can someone suggest an existing function or class to perform such a task?

Thanks!

Bosconian wrote:
> I'm looking for a method to compare two strings and grade them for
> similarity.

http://docs.php.net/en/function.levenshtein.html

or

http://docs.php.net/en/function.similar-text.html

Cheers,
Nhcholas Sherlock

"Nicholas Sherlock" <n_sherlock@hotmail.com> wrote in message
news:d4cpp0$1jc$1@lust.ihug.co.nz...
> Bosconian wrote:
> > I'm looking for a method to compare two strings and grade them for
> > similarity.
>
> http://docs.php.net/en/function.levenshtein.html
>
> or
>
> http://docs.php.net/en/function.similar-text.html
>
> Cheers,
> Nhcholas Sherlock

Nhcholas, I'm embarrassed to say that I didn't check php.net before posting
my message. Shame on me, but thanks for the tip!

BTW, would you happen to know if this can be done at the query level?

"Nicholas Sherlock" <n_sherlock@hotmail.com> wrote in message
news:d4cpp0$1jc$1@lust.ihug.co.nz...
> Bosconian wrote:
> > I'm looking for a method to compare two strings and grade them for
> > similarity.
>
> http://docs.php.net/en/function.levenshtein.html
>
> or
>
> http://docs.php.net/en/function.similar-text.html
>
> Cheers,
> Nhcholas Sherlock

"Nicholas Sherlock" <n_sherlock@hotmail.com> wrote in message
news:d4cpp0$1jc$1@lust.ihug.co.nz...
> Bosconian wrote:
> > I'm looking for a method to compare two strings and grade them for
> > similarity.
>
> http://docs.php.net/en/function.levenshtein.html
>
> or
>
> http://docs.php.net/en/function.similar-text.html
>
> Cheers,
> Nhcholas Sherlock

BTW, would you happen to know if this can be done at the query level?

Bosconian wrote:
> "Nicholas Sherlock" <n_sherlock@hotmail.com> wrote in message
> news:d4cpp0$1jc$1@lust.ihug.co.nz...
>
>>Bosconian wrote:
>>
>>>I'm looking for a method to compare two strings and grade them for
>>>similarity.
>>
>>http://docs.php.net/en/function.levenshtein.html
>>
>>or
>>
>>http://docs.php.net/en/function.similar-text.html
>
>
> BTW, would you happen to know if this can be done at the query level?

Ah, do you want to something like this made up query:

SELECT * FROM mytable WHERE text IS SORT OF SIMILAR TO $mysearch ?

If so, you can't do this with PHP functions. You may be able to find an
add-on for your database server which will add functionality like this,
but I don't think that it comes standard with any databases.

Cheers,
Nicholas Sherlock

Nicholas Sherlock wrote:
> Bosconian wrote:
<snip>
> >>http://docs.php.net/en/function.similar-text.html
> > BTW, would you happen to know if this can be done at the query
level?
> Ah, do you want to something like this made up query:
>
> SELECT * FROM mytable WHERE text IS SORT OF SIMILAR TO $mysearch ?
>
> If so, you can't do this with PHP functions. You may be able to find
an
> add-on for your database server which will add functionality like
this,
> but I don't think that it comes standard with any databases.

Though MySQL supports user defined functions, in SQLite, it is easy
AFAIK (never tried); you can mix PHP user functions with query
<http://in2.php.net/sqlite>


--
<?php echo 'Just another PHP saint'; ?>
Email: rrjanbiah-at-Y!com Blog: http://rajeshanbiah.blogspot.com/

R. Rajesh Jeba Anbiah wrote:
> <http://in2.php.net/sqlite>

To avoid having everyone over for a party at _your_ local server, you
should trim your url: <http://php.net/sqlite> (it then jumps to a local
server appropriate for the visitor).


--
Firefox Web Browser - Rediscover the web - http://getffox.com/
Thunderbird E-mail and Newsgroups - http://gettbird.com/

Ewoud Dronkert wrote:
> R. Rajesh Jeba Anbiah wrote:
> > <http://in2.php.net/sqlite>
>
> To avoid having everyone over for a party at _your_ local server, you

> should trim your url: <http://php.net/sqlite> (it then jumps to a
local
> server appropriate for the visitor).

Oh, yes.

--
<?php echo 'Just another PHP saint'; ?>
Email: rrjanbiah-at-Y!com Blog: http://rajeshanbiah.blogspot.com/

"Ewoud Dronkert" <firstname@lastname.net.invalid> wrote in message
news:426b606b$0$187$e4fe514c@dreader4.news.xs4all. nl...
> R. Rajesh Jeba Anbiah wrote:
> > <http://in2.php.net/sqlite>
>
> To avoid having everyone over for a party at _your_ local server, you
> should trim your url: <http://php.net/sqlite> (it then jumps to a local
> server appropriate for the visitor).
>
>
> --
> Firefox Web Browser - Rediscover the web - http://getffox.com/
> Thunderbird E-mail and Newsgroups - http://gettbird.com/

I usually use the server in Finland. Less traffic than the stateside
servers.