1  #region License Information


2  /* HeuristicLab


3  * Copyright (C) 20022018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)


4  *


5  * This file is part of HeuristicLab.


6  *


7  * HeuristicLab is free software: you can redistribute it and/or modify


8  * it under the terms of the GNU General Public License as published by


9  * the Free Software Foundation, either version 3 of the License, or


10  * (at your option) any later version.


11  *


12  * HeuristicLab is distributed in the hope that it will be useful,


13  * but WITHOUT ANY WARRANTY; without even the implied warranty of


14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the


15  * GNU General Public License for more details.


16  *


17  * You should have received a copy of the GNU General Public License


18  * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.


19  */


20  #endregion


21 


22  using System;


23  using System.Collections.Generic;


24  using System.Linq;


25  using HeuristicLab.Collections;


26  using HeuristicLab.Common;


27  using HeuristicLab.Core;


28  using HeuristicLab.Data;


29  using HeuristicLab.Parameters;


30  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;


31 


32  namespace HeuristicLab.Operators {


33  /// <summary>


34  /// Selects one of its branches (if there are any) given a list of relative probabilities.


35  /// </summary>


36  [Item("StochasticMultiBranch", "Selects one of its branches (if there are any) given a list of relative probabilities.")]


37  [StorableClass]


38  public abstract class StochasticMultiBranch<T> : CheckedMultiOperator<T> where T : class, IOperator {


39  /// <summary>


40  /// Should return true if the StochasticMultiOperator should create a new child operation with the selected successor


41  /// or if it should create a new operation. If you need to shield the parameters of the successor you should return true here.


42  /// </summary>


43  protected abstract bool CreateChildOperation { get; }


44 


45  public ValueLookupParameter<DoubleArray> ProbabilitiesParameter {


46  get { return (ValueLookupParameter<DoubleArray>)Parameters["Probabilities"]; }


47  }


48  public ILookupParameter<IRandom> RandomParameter {


49  get { return (ILookupParameter<IRandom>)Parameters["Random"]; }


50  }


51  public ValueParameter<BoolValue> TraceSelectedOperatorParameter {


52  get { return (ValueParameter<BoolValue>)Parameters["TraceSelectedOperator"]; }


53  }


54  public LookupParameter<StringValue> SelectedOperatorParameter {


55  get { return (LookupParameter<StringValue>)Parameters["SelectedOperator"]; }


56  }


57 


58  public DoubleArray Probabilities {


59  get { return ProbabilitiesParameter.Value; }


60  set { ProbabilitiesParameter.Value = value; }


61  }


62 


63  [StorableConstructor]


64  protected StochasticMultiBranch(bool deserializing) : base(deserializing) { }


65  protected StochasticMultiBranch(StochasticMultiBranch<T> original, Cloner cloner)


66  : base(original, cloner) {


67  }


68  /// <summary>


69  /// Initializes a new instance of <see cref="StochasticMultiOperator"/> with two parameters


70  /// (<c>Probabilities</c> and <c>Random</c>).


71  /// </summary>


72  public StochasticMultiBranch()


73  : base() {


74  Parameters.Add(new ValueLookupParameter<DoubleArray>("Probabilities", "The array of relative probabilities for each operator.", new DoubleArray()));


75  Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator to use."));


76  Parameters.Add(new LookupParameter<StringValue>("SelectedOperator", "If the TraceSelectedOperator flag is set, the name of the operator is traced in this parameter."));


77  Parameters.Add(new ValueParameter<BoolValue>("TraceSelectedOperator", "Indicates, if the selected operator should be traced.", new BoolValue(false)));


78  SelectedOperatorParameter.Hidden = false;


79  }


80 


81  [StorableHook(HookType.AfterDeserialization)]


82  private void AfterDeserialization() {


83  // BackwardsCompatibility3.3


84  #region Backwards compatible code, remove with 3.4


85  if (!Parameters.ContainsKey("SelectedOperator")) {


86  Parameters.Add(new LookupParameter<StringValue>("SelectedOperator", "If the TraceSelectedOperator flag is set, the name of the operator is traced in this parameter."));


87  SelectedOperatorParameter.Hidden = false;


88  }


89  if (!Parameters.ContainsKey("TraceSelectedOperator")) {


90  Parameters.Add(new ValueParameter<BoolValue>("TraceSelectedOperator", "Indicates, if the selected operator should be traced.", new BoolValue(false)));


91  }


92  #endregion


93  }


94 


95  protected override void Operators_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IndexedItem<T>> e) {


96  base.Operators_ItemsRemoved(sender, e);


97  if (Probabilities != null && Probabilities.Length > Operators.Count) {


98  List<double> probs = new List<double>(Probabilities.Cast<double>());


99  var sorted = e.Items.OrderByDescending(x => x.Index);


100  foreach (IndexedItem<T> item in sorted)


101  if (probs.Count > item.Index) probs.RemoveAt(item.Index);


102  Probabilities = new DoubleArray(probs.ToArray());


103  }


104  }


105 


106  protected override void Operators_ItemsAdded(object sender, HeuristicLab.Collections.CollectionItemsChangedEventArgs<IndexedItem<T>> e) {


107  base.Operators_ItemsAdded(sender, e);


108  if (Probabilities != null && Probabilities.Length < Operators.Count) {


109  double avg = (Probabilities.Where(x => x > 0).Count() > 0) ? (Probabilities.Where(x => x > 0).Average()) : (1);


110  // add the average of all probabilities in the respective places (the new operators)


111  var added = e.Items.OrderBy(x => x.Index).ToList();


112  int insertCount = 0;


113  DoubleArray probs = new DoubleArray(Operators.Count);


114  for (int i = 0; i < Operators.Count; i++) {


115  if (insertCount < added.Count && i == added[insertCount].Index) {


116  probs[i] = avg;


117  insertCount++;


118  } else if (i  insertCount < Probabilities.Length) {


119  probs[i] = Probabilities[i  insertCount];


120  } else probs[i] = avg;


121  }


122  Probabilities = probs;


123  }


124  }


125 


126  /// <summary>


127  /// Applies an operator of the branches to the current scope with a


128  /// specific probability.


129  /// </summary>


130  /// <exception cref="InvalidOperationException">Thrown when the list of probabilites does not


131  /// match the number of operators, the list of selected operators is empty,


132  /// or all selected operators have zero probabitlity.</exception>


133  /// <returns>A new operation with the operator that was selected followed by the current operator's successor.</returns>


134  public override IOperation InstrumentedApply() {


135  IRandom random = RandomParameter.ActualValue;


136  DoubleArray probabilities = ProbabilitiesParameter.ActualValue;


137  if (probabilities.Length != Operators.Count) {


138  throw new InvalidOperationException(Name + ": The list of probabilities has to match the number of operators");


139  }


140  IOperator successor = null;


141  int index = 1;


142  var checkedOperators = Operators.CheckedItems;


143  if (checkedOperators.Count() > 0) {


144  // select a random operator from the checked operators


145  double sum = (from indexedItem in checkedOperators select probabilities[indexedItem.Index]).Sum();


146  if (sum == 0) throw new InvalidOperationException(Name + ": All selected operators have zero probability.");


147  double r = random.NextDouble() * sum;


148  sum = 0;


149  foreach (var indexedItem in checkedOperators) {


150  sum += probabilities[indexedItem.Index];


151  if (sum > r) {


152  successor = indexedItem.Value;


153  index = indexedItem.Index;


154  break;


155  }


156  }


157  }


158  OperationCollection next = new OperationCollection(base.InstrumentedApply());


159  if (successor != null) {


160  if (TraceSelectedOperatorParameter.Value.Value)


161  SelectedOperatorParameter.ActualValue = new StringValue(index + ": " + successor.Name);


162 


163  if (CreateChildOperation)


164  next.Insert(0, ExecutionContext.CreateChildOperation(successor));


165  else next.Insert(0, ExecutionContext.CreateOperation(successor));


166  } else {


167  if (TraceSelectedOperatorParameter.Value.Value)


168  SelectedOperatorParameter.ActualValue = new StringValue("");


169  }


170  return next;


171  }


172  }


173 


174  /// <summary>


175  /// Selects one of its branches (if there are any) given a list of relative probabilities.


176  /// </summary>


177  [Item("StochasticMultiBranch", "Selects one of its branches (if there are any) given a list of relative probabilities.")]


178  [StorableClass]


179  public class StochasticMultiBranch : StochasticMultiBranch<IOperator> {


180  [StorableConstructor]


181  protected StochasticMultiBranch(bool deserializing) : base(deserializing) { }


182  protected StochasticMultiBranch(StochasticMultiBranch original, Cloner cloner)


183  : base(original, cloner) {


184  }


185  public StochasticMultiBranch() { }


186 


187  public override IDeepCloneable Clone(Cloner cloner) {


188  return new StochasticMultiBranch(this, cloner);


189  }


190 


191  protected override bool CreateChildOperation {


192  get { return false; }


193  }


194  }


195  }

