[ 
https://issues.apache.org/jira/browse/SPARK-3614?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14142860#comment-14142860
 ] 

RJ Nowling edited comment on SPARK-3614 at 9/22/14 5:52 PM:
------------------------------------------------------------

Thanks, Andrew! I'll do that.


was (Author: rnowling):
Thanks, Andrew! I'll do that.




-- 
em rnowl...@gmail.com
c 954.496.2314


> Filter on minimum occurrences of a term in IDF 
> -----------------------------------------------
>
>                 Key: SPARK-3614
>                 URL: https://issues.apache.org/jira/browse/SPARK-3614
>             Project: Spark
>          Issue Type: Improvement
>          Components: MLlib
>            Reporter: Jatinpreet Singh
>            Assignee: RJ Nowling
>            Priority: Minor
>              Labels: TFIDF
>
> The IDF class in MLlib does not provide the capability of defining a minimum 
> number of documents a term should appear in the corpus. The idea is to have a 
> cutoff variable which defines this minimum occurrence value, and the terms 
> which have lower frequency are ignored.
> Mathematically,
> IDF(t,D)=log( (|D|+1)/(DF(t,D)+1) ), for DF(t,D) >=minimumOccurance
> where, 
> D is the total number of documents in the corpus
> DF(t,D) is the number of documents that contain the term t
> minimumOccurance is the minimum number of documents the term appears in the 
> document corpus
> This would have an impact on accuracy as terms that appear in less than a 
> certain limit of documents, have low or no importance in TFIDF vectors.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org

Reply via email to