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Timestamp:
05/03/10 17:27:21 (14 years ago)
Author:
abeham
Message:

Changed StochasticMultiOperator to StochasticMultiBranch and adapted all operators #997

Location:
trunk/sources/HeuristicLab.Operators/3.3
Files:
1 deleted
2 edited

Legend:

Unmodified
Added
Removed
  • trunk/sources/HeuristicLab.Operators/3.3/HeuristicLab.Operators-3.3.csproj

    r3591 r3593  
    9292    <Compile Include="Assigner.cs" />
    9393    <Compile Include="AlgorithmOperator.cs" />
    94     <Compile Include="StochasticMultiOperator.cs" />
    9594    <Compile Include="MultiOperator.cs" />
    9695    <Compile Include="Operator.cs" />
     
    9998    <Compile Include="ScopeCleaner.cs" />
    10099    <Compile Include="StochasticBranch.cs" />
    101     <Compile Include="StochasticMultiBranch.cs" />
     100    <Compile Include="StochasticMultiBranch.cs">
     101      <SubType>Code</SubType>
     102    </Compile>
    102103    <Compile Include="SubScopesCreator.cs" />
    103104    <Compile Include="SubScopesMixer.cs" />
  • trunk/sources/HeuristicLab.Operators/3.3/StochasticMultiBranch.cs

    r3425 r3593  
    2020#endregion
    2121
     22using System;
     23using System.Collections.Generic;
     24using System.Linq;
     25using HeuristicLab.Collections;
    2226using HeuristicLab.Core;
     27using HeuristicLab.Data;
     28using HeuristicLab.Parameters;
    2329using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
     30using HeuristicLab.PluginInfrastructure;
    2431
    2532namespace HeuristicLab.Operators {
    2633  /// <summary>
    27   /// Branch of operators that have different probabilities to get executed.
     34  /// Selects one of its branches (if there are any) given a list of relative probabilities.
    2835  /// </summary>
    29   [Item("StochasticMultiBranch", "Branch of operators that have different probabilities to get executed.")]
     36  [Item("StochasticMultiBranch<T>", "Selects one of its branches (if there are any) given a list of relative probabilities.")]
    3037  [StorableClass]
    31   public class StochasticMultiBranch : StochasticMultiOperator<IOperator> {
    32     protected override bool CreateChildOperation {
     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 {
    3344      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 parameters
     63    /// (<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 a
     104    /// specific probability.
     105    /// </summary>
     106    /// <exception cref="InvalidOperationException">Thrown when the list of probabilites does not
     107    /// 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 operators
     120        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;
    34139    }
    35140  }
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