[ 
https://issues.apache.org/jira/browse/LUCENE-2749?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Steven Rowe updated LUCENE-2749:
--------------------------------

    Description: 
The co-occurrence filter to be developed here will output sets of tokens that 
co-occur within a given window onto a token stream.  

These token sets can be ordered either lexically (to allow order-independent 
matching/counting) or positionally (e.g. sliding windows of positionally 
ordered co-occurring terms that include all terms in the window are called 
n-grams or shingles). 

The parameters to this filter will be: 

* window size: this can be a fixed sequence length, sentence/paragraph context 
(these will require sentence/paragraph segmentation, which is not in Lucene 
yet), or over the entire token stream (full field width)
* minimum number of co-occurring terms: >= 2
* maximum number of co-occurring terms: <= window size
* token set ordering (lexical or positional)

One use case for co-occurring token sets is as candidates for collocations.

  was:
Sometimes people want to know if words have co-occurred within a specific 
window onto the token stream, but don't care what the order is.  A Lucene token 
filter (LexicallySortedWindowFilter?), perhaps implemented as a ShingleFilter 
sub-class, could provide this functionality.

This feature would allow for exact term set equality queries (in the case of a 
full-field-width window).


        Summary: Co-occurrence filter  (was: Lexically sorted shingle filter)

> Co-occurrence filter
> --------------------
>
>                 Key: LUCENE-2749
>                 URL: https://issues.apache.org/jira/browse/LUCENE-2749
>             Project: Lucene - Java
>          Issue Type: New Feature
>          Components: Analysis
>    Affects Versions: 3.1, 4.0
>            Reporter: Steven Rowe
>            Priority: Minor
>             Fix For: 3.1, 4.0
>
>
> The co-occurrence filter to be developed here will output sets of tokens that 
> co-occur within a given window onto a token stream.  
> These token sets can be ordered either lexically (to allow order-independent 
> matching/counting) or positionally (e.g. sliding windows of positionally 
> ordered co-occurring terms that include all terms in the window are called 
> n-grams or shingles). 
> The parameters to this filter will be: 
> * window size: this can be a fixed sequence length, sentence/paragraph 
> context (these will require sentence/paragraph segmentation, which is not in 
> Lucene yet), or over the entire token stream (full field width)
> * minimum number of co-occurring terms: >= 2
> * maximum number of co-occurring terms: <= window size
> * token set ordering (lexical or positional)
> One use case for co-occurring token sets is as candidates for collocations.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to