source: branches/1772_HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSolutionPruningOptimizer.cs

#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2013 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 HEAL.Attic;
using HeuristicLab.Core;
using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;

namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
  [Item("SymbolicDataAnalysisSolutionPruningOptimizer", "An operator which automatically removes nodes that have a negative impact from the tree model, optimizing the remaining constants.")]
  [StorableType("8F0C09F6-7138-4D95-9EB0-F65D8E8C3811")]
  public abstract class SymbolicDataAnalysisSolutionPruningOptimizer {
    public abstract ISymbolicDataAnalysisSolution PruneAndOptimizeSolution(ISymbolicDataAnalysisSolution solution);

    protected ConstantTreeNode MakeConstantTreeNode(double value) {
      var constant = new Constant { MinValue = value - 1, MaxValue = value + 1 };
      var constantTreeNode = (ConstantTreeNode)constant.CreateTreeNode();
      constantTreeNode.Value = value;
      return constantTreeNode;
    }

    protected void ReplaceWithConstantNode(ISymbolicExpressionTreeNode originalNode, ISymbolicExpressionTreeNode constantNode) {
      var parent = originalNode.Parent;
      var index = parent.IndexOfSubtree(originalNode);
      parent.RemoveSubtree(index);
      parent.InsertSubtree(index, constantNode);
    }
  }
}