"Nested macros"

Hi!

I have an example set with different attributes and a class. For all regular attributes I want to calculate the average of examples labled false. Then I want to use this averages and calculate for every example the difference to this average.

I planned to use a feature iterator (over all false examples) to calculate all averages and store them in macros. Then i wanted to use another feature iterator (over all examples) to calculate the difference in an AttributeConstruction:

<operator name="Calculate Averages" class="OperatorChain" expanded="no">
    <operator name="Work on copy" class="IOMultiplier">
        <parameter key="io_object"	value="ExampleSet"/>
    </operator>
           
    <operator name="Only non-pain" class="ExampleFilter">
       <parameter key="condition_class"	value="attribute_value_filter"/>
       <parameter key="parameter_string"	value="pain=no"/>
    </operator>

    <operator name="For All Distances and Angles" class="FeatureIterator" expanded="no">
        <parameter key="filter"	value="dist.*|angle.*"/>
        
        <operator name="Calculate Average" class="DataMacroDefinition">
            <parameter key="macro"	value="avg_%{loop_feature}"/>
            <parameter key="macro_type"	value="statistics"/>
            <parameter key="attribute_name"	value="%{loop_feature}"/>
         </operator>
                
     </operator>
            
     <operator name="Delete Copy" class="IOConsumer">
          <parameter key="io_object"	value="ExampleSet"/>
                <parameter key="deletion_type"	value="delete_one"/>
      </operator>
</operator>
        
<operator name="Calculate Relations" class="OperatorChain" expanded="yes">
       
    <operator name="For All Distances and Angles (2)" class="FeatureIterator" expanded="yes">
        <parameter key="filter"	value="whatever.*"/>
         <parameter key="work_on_input"	value="false"/>
                
             <operator name="AttributeConstruction" class="AttributeConstruction">
                 <list key="function_descriptions">
                      <parameter key="%{loop_feature}_Quotient"	value="%{avg_%{loop_feature}}"/>
                 </list>
              </operator>
      </operator>
</operator>

The problem is this line:

<parameter key="%{loop_feature}_Quotient"	value="%{avg_%{loop_feature}}"/>

I get an UserError: SyntaxError. By now I know that is is obviously not possible to have an macro in a macro name. How can I come over this problem?

I would also be happy about a totally different solution. (Please consider that I'm dealing with about 4000 attributes which are not known jet. So assigning individual names is not possible).