@SuppressWarnings("unused")
    public I_DataSet prunePositives(I_DataSet ds) 
    {
	if(ds != null)
	{
	    I_DataSet prunedDataset = new DataSet();

	    for(int r = 0; r < ds.getRows(); r++)
	    {
		I_InputPattern p = ds.getDataRow(r);

		String classification = p.getClassMembership();
		if(!classification.equals(Constants.PULSAR))
		    prunedDataset.addRow(p);
	    }

	    if(prunedDataset != null)
		return prunedDataset;
	    else
		return null;
	}
	else
	    return null;
    }