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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