spark-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Sean Owen (JIRA)" <j...@apache.org>
Subject [jira] [Resolved] (SPARK-20265) Improve Prefix'span pre-processing efficiency
Date Thu, 13 Apr 2017 08:45:41 GMT

     [ https://issues.apache.org/jira/browse/SPARK-20265?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Sean Owen resolved SPARK-20265.
-------------------------------
       Resolution: Fixed
    Fix Version/s: 2.2.0

Issue resolved by pull request 17575
[https://github.com/apache/spark/pull/17575]

> Improve Prefix'span pre-processing efficiency
> ---------------------------------------------
>
>                 Key: SPARK-20265
>                 URL: https://issues.apache.org/jira/browse/SPARK-20265
>             Project: Spark
>          Issue Type: Improvement
>          Components: MLlib
>    Affects Versions: 2.1.0
>            Reporter: Cyril de Vogelaere
>            Priority: Minor
>             Fix For: 2.2.0
>
>   Original Estimate: 0h
>  Remaining Estimate: 0h
>
> Given the sequence :
> 0 4 0 1 0 2 0 5 0 2 0 4 0 5
> And supposing only item 4 and 5 are frequent. The current implementation will clean the
sequence as follow.
> 0 4 0 0 0 5 0 0 4 0 5
> Which, while still giving the same results, inneficiently leave sequences of zero. A
quick change in the code can removes those sequence of zeros, while not changing the returned
solutions.
> I ran test to mesure efficiency gain, they are available in the graph below :
> https://postimg.org/image/9x6ireuvn/
> As you can see, the performance increase is signifiant.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

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


Mime
View raw message