W-Apriori doesn't work. need help

edfred

Hi at all,

i want to use the W-Apriori operator to generate some association rules, but it's not working.
I am using the rapidminer version 4.3.
This is my operatorchain:

root
|  |
|  |-Textinput
|    |
|    |-StringTokenizer
|    |-GermanStopwordFilter
|    |-ToLowerCaseConverter
|    |-TokenLengthFGilter
|
|-ExampleSetWriter
|
|-W-Apriori

If I press the start-button, there is a an exception like this:

Error: 905 External Error
Error in: W-Apriori (W-Apriori) W-Apriori caused an error: weka.core.UnsupportedAttributeTypeException: weka.associations.Apriori: Cannot handle numeric attributes! An external program or library has reported an error. Please see the documentation of this program or library for further information.

How can I get binary attributes. I think I have to converte them somehow.

Can youo give me an example operator chain, where it's works?

Best regards
edfred

earmijo

If you are using "Binary Ocurrences" as your Vector Creation choice, you will have a matrix of 0/1s. You still have to transform it into a matrix of true/false which is the input form accepted by the Asociators like Weka-apriori.  You can do this with the Numerical2Binomial converter (Preprocessing/Attributes/Filter/Converter/...).

<operator name="Root" class="Process" expanded="yes">
    <operator name="TextInput" class="TextInput" expanded="yes">
        <parameter key="attributes"	value=""/>
        <parameter key="create_text_visualizer"	value="true"/>
        <parameter key="default_content_encoding"	value="ISO-8859-1"/>
        <list key="namespaces">
        </list>
        <parameter key="on_the_fly_pruning"	value="3"/>
        <parameter key="prune_below"	value="2"/>
        <list key="texts">
          <parameter key="graphics"	value="../data/newsgroup/graphics"/>
          <parameter key="hardware"	value="../data/newsgroup/hardware"/>
        </list>
        <parameter key="vector_creation"	value="BinaryOccurrences"/>
        <operator name="StringTokenizer" class="StringTokenizer">
        </operator>
        <operator name="EnglishStopwordFilter" class="EnglishStopwordFilter">
        </operator>
        <operator name="TokenLengthFilter" class="TokenLengthFilter">
            <parameter key="min_chars"	value="3"/>
        </operator>
    </operator>
    <operator name="Numerical2Binominal" class="Numerical2Binominal">
    </operator>
    <operator name="W-Apriori" class="W-Apriori">
    </operator>
</operator>