title: How to select attributes with respect to Information Gain in weka?
body: <p>i am working in weka for text classification. I have total of 113232 attributes in vocabulary out of which i want to select top 10, 000 attributes. Follwing is setting of my informationGain filter</p>
  
  <pre><code>AttributeSelection featureSelectionFilter = new AttributeSelection();
  
  InfoGainAttributeEval informationGain = new InfoGainAttributeEval();
  
   Ranker ranker = new Ranker();
   ranker.setNumToSelect(10000);
   ranker.setThreshold(0);
  </code></pre>
  
  <p>I assumed that it may arrange the attributes in descending order with respect to their information gain, i am not sure i am right or wrong in my assumption here is an image of three attributes </p>
  
  <p><img src="https://i.stack.imgur.com/mNCc5.png" alt="enter image description here"></p>
  
  <p>The maximum value, std dev, mean all of first attribute is higher than other which may indicate its importance but these values for second attribute is less than 3rd ? Is it right ? How to IG select attributes from vocabulary when we set numToSelect(10, 000); ?</p>