#region License Information
/* HeuristicLab
* Copyright (C) 2002-2008 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 .
*/
#endregion
using System;
using System.Collections.Generic;
using System.Text;
using HeuristicLab.Data;
using HeuristicLab.Core;
using System.Xml;
using HeuristicLab.Constraints;
using HeuristicLab.DataAnalysis;
namespace HeuristicLab.Functions {
public class Constant : FunctionBase {
public const string VALUE = "Value";
public override string Description {
get { return "Returns the value of local variable 'Value'."; }
}
public Constant()
: base() {
AddVariableInfo(new VariableInfo(VALUE, "The constant value", typeof(ConstrainedDoubleData), VariableKind.None));
GetVariableInfo(VALUE).Local = true;
ConstrainedDoubleData valueData = new ConstrainedDoubleData();
// initialize a default range for the contant value
valueData.AddConstraint(new DoubleBoundedConstraint(-20.0, 20.0));
HeuristicLab.Core.Variable value = new HeuristicLab.Core.Variable(VALUE, valueData);
AddVariable(value);
// constant can't have suboperators
AddConstraint(new NumberOfSubOperatorsConstraint(0, 0));
}
//public override IFunctionTree GetTreeNode() {
// return new ConstantFunctionTree(this);
//}
// can't apply a constant
public override double Apply(Dataset dataset, int sampleIndex, double[] args) {
throw new NotSupportedException();
}
public override void Accept(IFunctionVisitor visitor) {
visitor.Visit(this);
}
}
class ConstantFunctionTree : FunctionTree {
private ConstrainedDoubleData value;
public ConstantFunctionTree() : base() { }
public ConstantFunctionTree(Constant constant) : base(constant) {
UpdateCachedValues();
}
private void UpdateCachedValues() {
value = (ConstrainedDoubleData)GetLocalVariable(Constant.VALUE).Value;
}
public override double Evaluate(Dataset dataset, int sampleIndex) {
return value.Data;
}
public override object Clone(IDictionary clonedObjects) {
ConstantFunctionTree clone = new ConstantFunctionTree();
clonedObjects.Add(clone.Guid, clone);
FillClone(clone, clonedObjects);
clone.UpdateCachedValues();
return clone;
}
public override void Populate(System.Xml.XmlNode node, IDictionary restoredObjects) {
base.Populate(node, restoredObjects);
UpdateCachedValues();
}
}
}