Changeset 3597 for trunk/sources/HeuristicLab.Operators/3.3
- Timestamp:
- 05/03/10 17:42:24 (14 years ago)
- Location:
- trunk/sources/HeuristicLab.Operators/3.3
- Files:
-
- 1 added
- 2 edited
Legend:
- Unmodified
- Added
- Removed
-
trunk/sources/HeuristicLab.Operators/3.3/HeuristicLab.Operators-3.3.csproj
r3593 r3597 92 92 <Compile Include="Assigner.cs" /> 93 93 <Compile Include="AlgorithmOperator.cs" /> 94 <Compile Include="StochasticMultiBranchOfT.cs" /> 94 95 <Compile Include="MultiOperator.cs" /> 95 96 <Compile Include="Operator.cs" /> -
trunk/sources/HeuristicLab.Operators/3.3/StochasticMultiBranch.cs
r3593 r3597 34 34 /// Selects one of its branches (if there are any) given a list of relative probabilities. 35 35 /// </summary> 36 [Item("StochasticMultiBranch <T>", "Selects one of its branches (if there are any) given a list of relative probabilities.")]36 [Item("StochasticMultiBranch", "Selects one of its branches (if there are any) given a list of relative probabilities.")] 37 37 [StorableClass] 38 public 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 virtual bool CreateChildOperation { 38 public class StochasticMultiBranch : StochasticMultiBranch<IOperator> { 39 protected override bool CreateChildOperation { 44 40 get { return false; } 45 }46 47 public ValueLookupParameter<DoubleArray> ProbabilitiesParameter {48 get { return (ValueLookupParameter<DoubleArray>)Parameters["Probabilities"]; }49 }50 public ILookupParameter<IRandom> RandomParameter {51 get { return (ILookupParameter<IRandom>)Parameters["Random"]; }52 }53 54 public DoubleArray Probabilities {55 get { return ProbabilitiesParameter.Value; }56 set { ProbabilitiesParameter.Value = value; }57 }58 59 [StorableConstructor]60 protected StochasticMultiBranch(bool deserializing) : base(deserializing) { }61 /// <summary>62 /// Initializes a new instance of <see cref="StochasticMultiOperator"/> with two parameters63 /// (<c>Probabilities</c> and <c>Random</c>).64 /// </summary>65 public StochasticMultiBranch()66 : base() {67 Parameters.Add(new ValueLookupParameter<DoubleArray>("Probabilities", "The array of relative probabilities for each operator.", new DoubleArray()));68 Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator to use."));69 }70 71 protected override void Operators_ItemsRemoved(object sender, CollectionItemsChangedEventArgs<IndexedItem<T>> e) {72 base.Operators_ItemsRemoved(sender, e);73 if (Probabilities != null && Probabilities.Length > Operators.Count) {74 List<double> probs = new List<double>(Probabilities.Cast<double>());75 var sorted = e.Items.OrderByDescending(x => x.Index);76 foreach (IndexedItem<T> item in sorted)77 if (probs.Count > item.Index) probs.RemoveAt(item.Index);78 Probabilities = new DoubleArray(probs.ToArray());79 }80 }81 82 protected override void Operators_ItemsAdded(object sender, HeuristicLab.Collections.CollectionItemsChangedEventArgs<IndexedItem<T>> e) {83 base.Operators_ItemsAdded(sender, e);84 if (Probabilities != null && Probabilities.Length < Operators.Count) {85 double avg = (Probabilities.Where(x => x > 0).Count() > 0) ? (Probabilities.Where(x => x > 0).Average()) : (1);86 // add the average of all probabilities in the respective places (the new operators)87 var added = e.Items.OrderBy(x => x.Index).ToList();88 int insertCount = 0;89 DoubleArray probs = new DoubleArray(Operators.Count);90 for (int i = 0; i < Operators.Count; i++) {91 if (insertCount < added.Count && i == added[insertCount].Index) {92 probs[i] = avg;93 insertCount++;94 } else if (i - insertCount < Probabilities.Length) {95 probs[i] = Probabilities[i - insertCount];96 } else probs[i] = avg;97 }98 Probabilities = probs;99 }100 }101 102 /// <summary>103 /// Applies an operator of the branches to the current scope with a104 /// specific probability.105 /// </summary>106 /// <exception cref="InvalidOperationException">Thrown when the list of probabilites does not107 /// match the number of operators, the list of selected operators is empty,108 /// or all selected operators have zero probabitlity.</exception>109 /// <returns>A new operation with the operator that was selected followed by the current operator's successor.</returns>110 public override IOperation Apply() {111 IRandom random = RandomParameter.ActualValue;112 DoubleArray probabilities = ProbabilitiesParameter.ActualValue;113 if (probabilities.Length != Operators.Count) {114 throw new InvalidOperationException(Name + ": The list of probabilities has to match the number of operators");115 }116 IOperator successor = null;117 var checkedOperators = Operators.CheckedItems;118 if (checkedOperators.Count() > 0) {119 // select a random operator from the checked operators120 double sum = (from indexedItem in checkedOperators select probabilities[indexedItem.Index]).Sum();121 if (sum == 0) throw new InvalidOperationException(Name + ": All selected operators have zero probability.");122 double r = random.NextDouble() * sum;123 sum = 0;124 foreach (var indexedItem in checkedOperators) {125 sum += probabilities[indexedItem.Index];126 if (sum > r) {127 successor = indexedItem.Value;128 break;129 }130 }131 }132 OperationCollection next = new OperationCollection(base.Apply());133 if (successor != null) {134 if (CreateChildOperation)135 next.Insert(0, ExecutionContext.CreateChildOperation(successor));136 else next.Insert(0, ExecutionContext.CreateOperation(successor));137 }138 return next;139 41 } 140 42 }
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