some questions about RM

dan76dan76 MemberPosts:6Contributor II
inHelp
hi there,

i have some question and i think one of you can answer it surely.

1. the SOM-plot: could you tell me the decrease rate of the learning factor and the radius factor or can i read it somewhere?

2. is there an operator, that shows the silhouette-coeffizient and/or the compactness of the clustering eg kmedoid?

thanks for help.

dan

Answers

  • IngoRMIngoRM Administrator, Moderator, Employee, RapidMiner Certified Analyst, RapidMiner Certified Expert, Community Manager, RMResearcher, Member, University ProfessorPosts:1,751RM Founder
    Hi,

    1. the SOM-plot: could you tell me the decrease rate of the learning factor and the radius factor or can i read it somewhere?
    I had to make a look into the code - which would also has been possible for you;)

    However, the adaptation is done via

    learnRateCurrent = learnRateStart * Math.pow((learnRateEnd / learnRateStart), (((double) time) / ((double) maxtime)));
    with learnRateStart = 0.8 and learnRateEnd = 0.01.

    The radius is adapted by

    adaptationRadiusStart * Math.pow((adaptationRadiusEnd / adaptationRadiusStart), (((double) time) / ((double) maxtime)));
    with start = 5 and end = 1.

    2. is there an operator, that shows the silhouette-coeffizient and/or the compactness of the clustering eg kmedoid?
    I do not get the point here. If the quesiton is: "is there a kmedoid?" the answer is "yes". If the question targets at cluster evaluation methods, you will find those in the "performance" operator group.

    Cheers,
    Ingo
  • dan76dan76 MemberPosts:6Contributor II
    Thanks for the fast reply.

    I run 2 kmedoids clustering one with k=5 and one with k=8.

    I dont know as i can compare the quality? I have read somewhere that the quality of a cluster is defind as the sum of the distance of all members to the medoid. And the quality of the clustering bei the sum of the clusterquality. That is im looking for.

    I hope the description fit

    thanks again.

    Dan
  • IngoRMIngoRM Administrator, Moderator, Employee, RapidMiner Certified Analyst, RapidMiner Certified Expert, Community Manager, RMResearcher, Member, University ProfessorPosts:1,751RM Founder
    Hi Dan,

    as I said, you will find operators for calculating the performance of clustering (including the "inner cluster density" like you described it) in the group "Validation" - "Performance" - "Clustering". Here you can use for example the operators "ClusterCentroidEvaluator" or "ClusterDensityEvaluator".

    Cheers,
    Ingo
  • dan76dan76 MemberPosts:6Contributor II
    Hi Ingo,

    thanks, thats it.

    greetz

    Dan
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