FP-GROWTH Itemset - one of the items is oversupported

svtorykh
svtorykh New Altair Community Member
edited November 2024 in Community Q&A

Hi RM Team,

I have issue with FP-Growth operator.

 

My example set contains 32 columns across 12000 examples. For some reason one of the attributes (whichever has TRUE in the first example=first row) is always showing 94-95% support, although real support for this item is 4-5% across all examples. All other items are calculated properly. Any ideas?

 

Thanks!

Tagged:

Answers

  • svtorykh
    svtorykh New Altair Community Member

    Problem solved by converting TRUE/FALSE in excel file to 0 and 1 and then converting numerical to binomial in RM.

    I have another question though:) In the Associations Rule operator, I'm setting the min. confidence at 0.15, but in the results, I don't see the rules between 0.15 and 0.2. I see those rules if I set min confidence to 0.1. Why is this happening?

     

     

  • bernardo_pagnon
    bernardo_pagnon New Altair Community Member
    The same happened to me regarding the min confidence parameter.
  • YYH
    YYH
    Altair Employee
    Hi @bernardo_pagnon, could you share the sample data and process for us to investigate the issues? I tried to re-produce the bug by testing the template under //Samples/Templates/Market Basket Analysis/Market basket analysis. With a modified min confidence from 0.1 to 0.2, the association rules are updated correctly. BTW I am using 9.6. Thanks
  • bernardo_pagnon
    bernardo_pagnon New Altair Community Member
    Sure, there it is. I am using the Supermarket_extracted file, available at http://rapidminerbook.com/


  • YYH
    YYH
    Altair Employee
    The reason is that you enabled on the "checkbox find min number of itemsets:"
    If you keep the same high threshold on support but uncheck the option 


    You should get an updated frequency items (empty) in the result view.

    More info to cover the details of the min num of itemsets can be found here
    https://docs.rapidminer.com/latest/studio/operators/modeling/associations/fp_growth.html

  • bernardo_pagnon
    bernardo_pagnon New Altair Community Member
    You are correct, the subtlely of two major modes solved the problem.
    Thanks!!!
  • sgenzer
    sgenzer
    Altair Employee
    hello @bernardo_pagnon I will also add that the online http://rapidminerbook.com/ is very out-of-date and has not been maintained in years. I would strongly recommend using the RapidMiner Academy instead.

    Scott
  • bernardo_pagnon
    bernardo_pagnon New Altair Community Member
    Oh, I see. that is too bad, it would be good to have a reference of a RapidMiner book to give it to my students. Any suggestions besides RM Academy?

    Best,
    Bernardo
  • sgenzer
    sgenzer
    Altair Employee
    oh you're a professor? :smile: Let me change your rank and add you to the University Professor Stable. It has many KB pages including lists of books, etc..

    Why didn't you tell us? :smile:

    Scott


Categories