% Version: $Revision: 6177 $

\begin{verbatim}
import weka.core.*;
import weka.core.Capabilities.*;
import weka.filters.*;

public class SimpleBatch extends SimpleBatchFilter {

  public String globalInfo() {
    return   "A simple batch filter that adds an additional attribute 'blah' at the end "
           + "containing the index of the processed instance.";
  }

  public Capabilities getCapabilities() {
    Capabilities result = super.getCapabilities();
    result.enableAllAttributes();
    result.enableAllClasses();
    result.enable(Capability.NO_CLASS);  //// filter doesn't need class to be set//
    return result;
  }

  protected Instances determineOutputFormat(Instances inputFormat) {
    Instances result = new Instances(inputFormat, 0);
    result.insertAttributeAt(new Attribute("blah"), result.numAttributes());
    return result;
  }

  protected Instances process(Instances inst) {
    Instances result = new Instances(determineOutputFormat(inst), 0);
    for (int i = 0; i < inst.numInstances(); i++) {
      double[] values = new double[result.numAttributes()];
      for (int n = 0; n < inst.numAttributes(); n++)
        values[n] = inst.instance(i).value(n);
      values[values.length - 1] = i;
      result.add(new Instance(1, values));
    }
    return result;
  }

  public static void main(String[] args) {
    runFilter(new SimpleBatch(), args);
  }
}
\end{verbatim}
