FP--Growth <-> Apriori

cpc2

Hi,
I am currently using the FPGrowth and the WEKA-Apriori Operator on the Iris Dataset.
The Process looks like this:

<operator name="Root" class="Process" expanded="yes">
    <operator name="ArffExampleSource" class="ArffExampleSource">
        <parameter key="data_file" value="C:\Dokumente und Einstellungen\b\Eigene Dateien\rm_workspace\sample\data\iris.arff"/>
    </operator>
    <operator name="Numerical2Polynominal" class="Numerical2Polynominal">
    </operator>
    <operator name="W-Apriori" class="W-Apriori">
        <parameter key="M" value="0.0010"/>
        <parameter key="I" value="true"/>
    </operator>
</operator>


Both the FPGrwoth and the Apriori Op have a min_support of 0.001 . The other options are Standard.

My question is: Why is the Weka Op able to find Itemsets and the FPGrowth Op not ? Even when i lower the min_support FPGrowth doesn't
find any Itemsets at all.

haddock

My question is: Why is the Weka Op able to find Itemsets and the FPGrowth Op not ? Even when i lower the min_support FPGrowth doesn't find any Itemsets at all.

The answer is in the documentation...

Please note that the given data set is only allowed to contain binominal attributes, i.e. nominal attributes with only two different values. Simply use the provided preprocessing operators in order to transform your data set. The necessary operators are the discretization operators for changing the value types of numerical attributes to nominal and the operator Nominal2Binominal for transforming nominal attributes into binominal / binary ones.

and here is an example..

<operator name="Root" class="Process" expanded="yes">
    <operator name="ArffExampleSource" class="ArffExampleSource">
        <parameter key="data_file"	value="C:\Documents and Settings\Alien\My Documents\rm_workspace\sample\data\iris.arff"/>
    </operator>
    <operator name="Numerical2Polynominal" class="Numerical2Polynominal">
    </operator>
    <operator name="Nominal2Binominal" class="Nominal2Binominal">
    </operator>
    <operator name="W-Apriori" class="W-Apriori" activated="no">
        <parameter key="M"	value="0.0010"/>
        <parameter key="I"	value="true"/>
    </operator>
    <operator name="FPGrowth" class="FPGrowth">
        <parameter key="min_number_of_itemsets"	value="1"/>
        <parameter key="min_support"	value="0.0010"/>
    </operator>
</operator>