"Problem with Feature Selection"

vitalimario

Hi,


I am trying to perform Feature Selection, then apply the reduced subset of features to a J48 tree and finally present the tree to the output.

As you will see i have the 'create_complete_model option' checked
Unfortunately *all* tutorials of feature selection in RM use either SVM or NearestNeigbours models which both do not return an output!

Here is my setting :

<operator name="Root" class="Process" expanded="yes">
    <operator name="CSVExampleSource" class="CSVExampleSource">
        <parameter key="filename" value="c::\MyDocuments\score.csv"/>
        <parameter key="label_name" value="class"/>
    </operator>
    <operator name="FeatureSelection" class="FeatureSelection" expanded="yes">
        <parameter key="selection_direction" value="backward"/>
        <operator name="SimpleValidation" class="SimpleValidation" expanded="yes">
            <parameter key="create_complete_model" value="true"/>
            <operator name="W-J48" class="W-J48">
            </operator>
            <operator name="ApplierChain" class="OperatorChain" expanded="yes">
                <operator name="ModelApplier" class="ModelApplier">
                    <list key="application_parameters">
                    </list>
                </operator>
                <operator name="Performance" class="Performance">
                </operator>
            </operator>
        </operator>
        <operator name="ProcessLog" class="ProcessLog">
            <list key="log">
              <parameter key="Generation" value="operator.LibSVMLearner.value.applycount"/>
            </list>
        </operator>
    </operator>
</operator>




What am i doing wrong ?  ???

steffen

Hello

I am afraid I got you wrong, but:
The decision tree you create is used within the "performance measurement"-process to determine the (sub-)optimal set of features. If you want to create a Decision Tree with the best feature subset you must add something like this (at top level):

    <operator name="AttributeWeightSelection" class="AttributeWeightSelection">
    </operator>
    <operator name="W-J48 (2)" class="W-J48">
    </operator>

hope this was helpful,

Steffen