/*
 * $Id$
 *
 * This file is part of the Cloud Services Integration Platform (CSIP),
 * a Model-as-a-Service framework, API and application suite.
 *
 * 2012-2022, Olaf David and others, OMSLab, Colorado State University.
 *
 * OMSLab licenses this file to you under the MIT license.
 * See the LICENSE file in the project root for more information.
 */
package csip.cosu;

/**
 *
 */
class ABSDIFFLOG extends ObjFunc {

  @Override
  public String name() {
    return "Absolute Diff LOG";
  }


  @Override
  public double eval(double[] obs, double[] sim, double missing) {
    checkArrays(obs, sim);
    double abs = 0;
    for (int i = 0; i < obs.length; i++) {
      if (obs[i] > missing) {
        double measured = obs[i];
        double simulated = sim[i];
        if (measured == 0) {
          measured = 0.0000001;
        } else if (measured < 0) {
          throw new RuntimeException("Error on Absolute Difference (log): Observed value is negative.");
        }
        if (simulated == 0) {
          simulated = 0.0000001;
        } else if (simulated < 0) {
          throw new RuntimeException("Error on Absolute Difference (log): Simulated value is negative.");
        }
        abs += Math.abs(Math.log(measured) - Math.log(simulated));
      }
    }
    return abs;
  }


  @Override
  public int direction() {
    return -1;
  }


  @Override
  public int optimum() {
    return 0;
  }
  
}