source: branches/2708_ScopedAlgorithms/HeuristicLab.Problems.Knapsack/3.3/MoveEvaluators/KnapsackOneBitflipMoveEvaluator.cs @ 16123

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Encodings.BinaryVectorEncoding;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Problems.Knapsack {
  /// <summary>
  /// An operator to evaluate one bitflip moves.
  /// </summary>
  [Item("KnapsackOneBitflipMoveEvaluator", "Base class for evaluating one bitflip moves.")]
  [StorableClass]
  public class KnapsackOneBitflipMoveEvaluator : KnapsackMoveEvaluator, IOneBitflipMoveOperator {
    public ILookupParameter<OneBitflipMove> OneBitflipMoveParameter {
      get { return (ILookupParameter<OneBitflipMove>)Parameters["OneBitflipMove"]; }
    }

    [StorableConstructor]
    protected KnapsackOneBitflipMoveEvaluator(bool deserializing) : base(deserializing) { }
    protected KnapsackOneBitflipMoveEvaluator(KnapsackOneBitflipMoveEvaluator original, Cloner cloner) : base(original, cloner) { }
    public KnapsackOneBitflipMoveEvaluator()
      : base() {
      Parameters.Add(new LookupParameter<OneBitflipMove>("OneBitflipMove", "The move to evaluate."));
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new KnapsackOneBitflipMoveEvaluator(this, cloner);
    }

    public override IOperation Apply() {
      var move = OneBitflipMoveParameter.ActualValue;
      var solution = BinaryVectorParameter.ActualValue;
      var weights = WeightsParameter.ActualValue;
      var values = ValuesParameter.ActualValue;
      var capacity = KnapsackCapacityParameter.ActualValue.Value;

      var totalWeight = !solution[move.Index] ? weights[move.Index] : 0.0;
      var totalValue = !solution[move.Index] ? values[move.Index] : 0.0; ;
      for (var i = 0; i < solution.Length; i++) {
        if (i == move.Index || !solution[i]) continue;
        totalWeight += weights[i];
        totalValue += values[i];
      }

      var moveQuality = totalWeight > capacity ? capacity - totalWeight : totalValue;

      if (MoveQualityParameter.ActualValue == null) MoveQualityParameter.ActualValue = new DoubleValue(moveQuality);
      else MoveQualityParameter.ActualValue.Value = moveQuality;
      return base.Apply();
    }
  }
}