code: package edu.cmu.tetrad.algcomparison.statistic;
  
  import edu.cmu.tetrad.algcomparison.statistic.utils.ArrowConfusion;
  import edu.cmu.tetrad.graph.Graph;
  
  /**
   * The 2-cycle precision. This counts 2-cycles manually, wherever they occur in the graphs.
   * The true positives are the number of 2-cycles in both the true and estimated graphs.
   * Thus, if the true does not contains X->Y,Y->X and estimated graph does contain it,
   * one false positive is counted.
   *
   * @author jdramsey, rubens (November 2016)
   */
  public class TwoCycleFalseNegative implements Statistic {
      static final long serialVersionUID = 23L;
  
      @Override
      public String getAbbreviation() {
          return "2CFN";
      }
  
      @Override
      public String getDescription() {
          return "2-cycle false negative";
      }
  
      @Override
      public double getValue(Graph trueGraph, Graph estGraph) {
          ArrowConfusion adjConfusion = new ArrowConfusion(trueGraph, estGraph);
          return (double) adjConfusion.getTwoCycleFn();
  
      }
  
      @Override
      public double getNormValue(double value) {
          return value;
      }
  }
  