source: trunk/sources/HeuristicLab.Encodings.SymbolicExpressionTreeEncoding/3.3/Manipulators/MultiSymbolicExpressionTreeManipulator.cs @ 3534

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 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 System;
using System.Linq;
using HeuristicLab.Collections;
using HeuristicLab.Core;
using HeuristicLab.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Data;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding.Interfaces;

namespace HeuristicLab.Encodings.SymbolicExpressionTreeEncoding.Manipulators {
  [Item("MultiSymbolicExpressionTreeManipulator", "Randomly selects and applies one of its manipulators every time it is called.")]
  [StorableClass]
  public class MultiSymbolicExpressionTreeManipulator : StochasticMultiOperator<ISymbolicExpressionTreeManipulator>, ISymbolicExpressionTreeManipulator, IStochasticOperator {
    private const string MaxTreeSizeParameterName = "MaxTreeSize";
    private const string MaxTreeHeightParameterName = "MaxTreeHeight";
    private const string SymbolicExpressionGrammarParameterName = "SymbolicExpressionGrammar";
    private const string SymbolicExpressionTreeParameterName = "SymbolicExpressionTree";

    public override bool CanChangeName {
      get { return false; }
    }
    protected override bool CreateChildOperation {
      get { return true; }
    }

    #region ISymbolicExpressionTreeManipulator Members
    public ILookupParameter<SymbolicExpressionTree> SymbolicExpressionTreeParameter {
      get { return (ILookupParameter<SymbolicExpressionTree>)Parameters[SymbolicExpressionTreeParameterName]; }
    }
    #endregion

    #region ISymbolicExpressionTreeOperator Members
    public IValueLookupParameter<IntValue> MaxTreeSizeParameter {
      get { return (IValueLookupParameter<IntValue>)Parameters[MaxTreeSizeParameterName]; }
    }
    public IValueLookupParameter<IntValue> MaxTreeHeightParameter {
      get { return (IValueLookupParameter<IntValue>)Parameters[MaxTreeHeightParameterName]; }
    }
    public ILookupParameter<ISymbolicExpressionGrammar> SymbolicExpressionGrammarParameter {
      get { return (ILookupParameter<ISymbolicExpressionGrammar>)Parameters[SymbolicExpressionGrammarParameterName]; }
    }
    #endregion


    [StorableConstructor]
    private MultiSymbolicExpressionTreeManipulator(bool deserializing) : base(deserializing) { }
    public MultiSymbolicExpressionTreeManipulator()
      : base() {
      Parameters.Add(new LookupParameter<SymbolicExpressionTree>(SymbolicExpressionTreeParameterName, "The symbolic expression tree on which the operator should be applied."));
      Parameters.Add(new ValueLookupParameter<IntValue>(MaxTreeSizeParameterName, "The maximal size (number of nodes) of the symbolic expression tree."));
      Parameters.Add(new ValueLookupParameter<IntValue>(MaxTreeHeightParameterName, "The maximal height of the symbolic expression tree (a tree with one node has height = 0)."));
      Parameters.Add(new LookupParameter<ISymbolicExpressionGrammar>(SymbolicExpressionGrammarParameterName, "The grammar that defines the allowed symbols and syntax of the symbolic expression trees."));

      Operators.Add(new FullTreeShaker());
      Operators.Add(new OnePointShaker());
      Operators.Add(new ChangeNodeTypeManipulation());
    }

    protected override void Operators_ItemsReplaced(object sender, CollectionItemsChangedEventArgs<IndexedItem<ISymbolicExpressionTreeManipulator>> e) {
      base.Operators_ItemsReplaced(sender, e);
      ParameterizeManipulators();
    }

    protected override void Operators_ItemsAdded(object sender, CollectionItemsChangedEventArgs<IndexedItem<ISymbolicExpressionTreeManipulator>> e) {
      base.Operators_ItemsAdded(sender, e);
      ParameterizeManipulators();
    }

    private void ParameterizeManipulators() {
      foreach (ISymbolicExpressionTreeManipulator manipulator in Operators.OfType<ISymbolicExpressionTreeManipulator>()) {
        manipulator.MaxTreeSizeParameter.ActualName = MaxTreeSizeParameter.Name;
        manipulator.MaxTreeHeightParameter.ActualName = MaxTreeHeightParameter.Name;
        manipulator.SymbolicExpressionGrammarParameter.ActualName = SymbolicExpressionGrammarParameter.Name;
        manipulator.SymbolicExpressionTreeParameter.ActualName = SymbolicExpressionTreeParameter.Name;
      }

      foreach (IStochasticOperator manipulator in Operators.OfType<IStochasticOperator>()) {
        manipulator.RandomParameter.ActualName = RandomParameter.Name;
      }
    }

    public override IOperation Apply() {
      if (Operators.Count == 0) throw new InvalidOperationException(Name + ": Please add at least one symbolic expression tree manipulator to choose from.");
      return base.Apply();
    }
  }
}