Add or Subtract a value from a macro's value

Prentice

Hi all,

I think this is an easy question, but I've been at it for far too long now.
OK, I've got a macro "NumberExamples" which is just a macro which gives me the number of examples for a certain attribute. 
The thing I want to do is add or subtract a number from that value, so let's say the value of "NumberExamples" = 14. I want to do this 14+1 and make it 15, or 14-3 and make it 11.
However, when I try to do this with generate macro it literally adds the 1 to the number making it 141. 
I know that this is probably very straightforward, I just don't know how.

Thanks
-Prentice

rfuentealba

Hello, @Prentice,

The macro value is always a string. What you want to do is to use eval() as a method to convert it to integer.

Please check this XML as an example on how to do what you want:

<?xml version="1.0" encoding="UTF-8"?><process version="9.2.000">
  <context>
    <input/>
    <output/>
    <macros/>
  </context>
  <operator activated="true" class="process" compatibility="9.2.000" expanded="true" name="Process">
    <parameter key="logverbosity" value="init"/>
    <parameter key="random_seed" value="2001"/>
    <parameter key="send_mail" value="never"/>
    <parameter key="notification_email" value=""/>
    <parameter key="process_duration_for_mail" value="30"/>
    <parameter key="encoding" value="SYSTEM"/>
    <process expanded="true">
      <operator activated="true" class="concurrency:loop" compatibility="9.2.000" expanded="true" height="82" name="Loop" width="90" x="45" y="34">
        <parameter key="number_of_iterations" value="5"/>
        <parameter key="iteration_macro" value="iterator"/>
        <parameter key="reuse_results" value="false"/>
        <parameter key="enable_parallel_execution" value="false"/>
        <process expanded="true">
          <operator activated="true" class="generate_macro" compatibility="9.2.000" expanded="true" height="82" name="Generate Macro" width="90" x="45" y="34">
            <list key="function_descriptions">
              <parameter key="value" value="eval(%{iterator}) * 50"/>
            </list>
          </operator>
          <operator activated="true" class="print_to_console" compatibility="9.2.000" expanded="true" height="82" name="Print to Console" width="90" x="179" y="34">
            <parameter key="log_value" value="%{value}"/>
          </operator>
          <connect from_port="input 1" to_op="Generate Macro" to_port="through 1"/>
          <connect from_op="Generate Macro" from_port="through 1" to_op="Print to Console" to_port="through 1"/>
          <connect from_op="Print to Console" from_port="through 1" to_port="output 1"/>
          <portSpacing port="source_input 1" spacing="0"/>
          <portSpacing port="source_input 2" spacing="0"/>
          <portSpacing port="sink_output 1" spacing="0"/>
          <portSpacing port="sink_output 2" spacing="0"/>
        </process>
      </operator>
      <connect from_op="Loop" from_port="output 1" 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>

Hope this helps,

Rodrigo.