title: (GAMS) how to use subsets when loading gdx-file?
body: <p>I don't think it's a complex problem, but I searched for a long time and didn't find a solution  :/
  I want to load data from a gdx-file and use set-items and subsets as identifiers (in the example below: different value for d and e and same value for all local modes).
  The gdx-file is written correctly, but the parameter includes only the value for set-items. How can I get GAMS to assign the value to all items of the according subset?
  I hope, the problem is clear and there is an easy solution. Thanks in advance!</p>
  
  <p>Code (simplified):</p>
  
  <pre><code>sets 
  
  mode /a, b, c, d, e/
  
  local_mode(mode) /a, b, c/
  ;
  
  parameter par_consumption_per_km(year, mode);
  
  $LOAD par_consumption_per_km;
  </code></pre>