weka.attributeSelection.BestFirst Java Examples

/**
 * set options to their default values
 */
protected void resetOptions() {

  m_trainSelector = new weka.attributeSelection.AttributeSelection();
  setEvaluator(new CfsSubsetEval());
  setSearch(new BestFirst());
  m_SelectedAttributes = null;
  m_FilterOptions = null;
}
 

public void selectFeatures(){
	AttributeSelection attSelection = new AttributeSelection();
    CfsSubsetEval eval = new CfsSubsetEval();
    BestFirst search = new BestFirst();
    attSelection.setEvaluator(eval);
    attSelection.setSearch(search);
    try {
		attSelection.SelectAttributes(iris);
		int[] attIndex = attSelection.selectedAttributes();
		System.out.println(Utils.arrayToString(attIndex));
	} catch (Exception e) {
	}
}
 

public void selectFeaturesWithFilter(){
	weka.filters.supervised.attribute.AttributeSelection filter = new weka.filters.supervised.attribute.AttributeSelection();
    CfsSubsetEval eval = new CfsSubsetEval();
    BestFirst search = new BestFirst();
    filter.setEvaluator(eval);
    filter.setSearch(search);
    try {
		filter.setInputFormat(iris);
		Instances newData = Filter.useFilter(iris, filter);
		System.out.println(newData);
	} catch (Exception e) {
	}
}
 

/**
  * Parses the options for this object. <p/>
  *
  <!-- options-start -->
  * Valid options are: <p/>
  * 
  * <pre> -S &lt;search method specification&gt;
  *  Full class name of search method, followed
  *  by its options.
  *  eg: "weka.attributeSelection.BestFirst -D 1"
  *  (default weka.attributeSelection.BestFirst)</pre>
  * 
  * <pre> -X &lt;number of folds&gt;
  *  Use cross validation to evaluate features.
  *  Use number of folds = 1 for leave one out CV.
  *  (Default = leave one out CV)</pre>
  * 
  * <pre> -E &lt;acc | rmse | mae | auc&gt;
  *  Performance evaluation measure to use for selecting attributes.
  *  (Default = accuracy for discrete class and rmse for numeric class)</pre>
  * 
  * <pre> -I
  *  Use nearest neighbour instead of global table majority.</pre>
  * 
  * <pre> -R
  *  Display decision table rules.
  * </pre>
  * 
  * <pre> 
  * Options specific to search method weka.attributeSelection.BestFirst:
  * </pre>
  * 
  * <pre> -P &lt;start set&gt;
  *  Specify a starting set of attributes.
  *  Eg. 1,3,5-7.</pre>
  * 
  * <pre> -D &lt;0 = backward | 1 = forward | 2 = bi-directional&gt;
  *  Direction of search. (default = 1).</pre>
  * 
  * <pre> -N &lt;num&gt;
  *  Number of non-improving nodes to
  *  consider before terminating search.</pre>
  * 
  * <pre> -S &lt;num&gt;
  *  Size of lookup cache for evaluated subsets.
  *  Expressed as a multiple of the number of
  *  attributes in the data set. (default = 1)</pre>
  * 
  <!-- options-end -->
  *
  * @param options the list of options as an array of strings
  * @throws Exception if an option is not supported
  */
 public void setOptions(String[] options) throws Exception {

   String optionString;

   resetOptions();

   optionString = Utils.getOption('X',options);
   if (optionString.length() != 0) {
     m_CVFolds = Integer.parseInt(optionString);
   }

   m_useIBk = Utils.getFlag('I',options);

   m_displayRules = Utils.getFlag('R',options);

   optionString = Utils.getOption('E', options);
   if (optionString.length() != 0) {
     if (optionString.equals("acc")) {
setEvaluationMeasure(new SelectedTag(EVAL_ACCURACY, TAGS_EVALUATION));
     } else if (optionString.equals("rmse")) {
setEvaluationMeasure(new SelectedTag(EVAL_RMSE, TAGS_EVALUATION));
     } else if (optionString.equals("mae")) {
setEvaluationMeasure(new SelectedTag(EVAL_MAE, TAGS_EVALUATION));
     } else if (optionString.equals("auc")) {
setEvaluationMeasure(new SelectedTag(EVAL_AUC, TAGS_EVALUATION));
     } else {
throw new IllegalArgumentException("Invalid evaluation measure");
     }
   }

   String searchString = Utils.getOption('S', options);
   if (searchString.length() == 0)
     searchString = weka.attributeSelection.BestFirst.class.getName();
   String [] searchSpec = Utils.splitOptions(searchString);
   if (searchSpec.length == 0) {
     throw new IllegalArgumentException("Invalid search specification string");
   }
   String searchName = searchSpec[0];
   searchSpec[0] = "";
   setSearch(ASSearch.forName(searchName, searchSpec));
 }