Math formula operator for RM?

holger

Hi,

for Knime there's a operator called "Math Formula" ( http://www.knime.org/downloads/extensions ), which allows you to evaluate free-form mathematical expressions. The result is appended as a new column to the input table.

Is there something similar for rm5? If not: how can I calculate a simple ratio, sum or product of 2 (or more) columns?

Best, Holger

IngoRM

Hi Holger,

sure, an operator like this is of course part of RapidMiner and called "Generate Attributes" in RapidMiner 5.

You can create multiple attributes at once and you can even re-use attributes which just have been created. The documentation of the operator gives you complete overview of all supported functions. By the way, "Generate Attributes" also support conditions and even nominal values like in the following example:

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<process version="5.0">
  <context>
    <input>
      <location/>
    </input>
    <output>
      <location/>
      <location/>
    </output>
    <macros/>
  </context>
  <operator activated="true" class="process" expanded="true" name="Process">
    <process expanded="true" height="251" width="413">
      <operator activated="true" class="generate_data" expanded="true" height="60" name="Generate Data" width="90" x="153" y="191"/>
      <operator activated="true" class="generate_attributes" expanded="true" height="76" name="Generate Attributes" width="90" x="313" y="165">
        <list key="function_descriptions">
          <parameter key="new_sum" value="att1 + att2"/>
          <parameter key="new_product" value="att2 * 4 * att5"/>
          <parameter key="new_condition" value="if (round(new_sum) &gt; 5, &quot;large&quot;, str(new_product))"/>
        </list>
      </operator>
      <connect from_op="Generate Data" from_port="output" to_op="Generate Attributes" to_port="example set input"/>
      <connect from_op="Generate Attributes" from_port="example set output" to_port="result 1"/>
      <portSpacing port="source_input 1" spacing="0"/>
      <portSpacing port="sink_result 1" spacing="0"/>
      <portSpacing port="sink_result 2" spacing="0"/>
    </process>
  </operator>
</process>

Cheers,
Ingo