#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.Core; using HeuristicLab.Data; using HeuristicLab.Persistence.Default.CompositeSerializers.Storable; namespace HeuristicLab.Random { /// /// Uniformly distributed random number generator. /// [EmptyStorableClass] public class UniformRandomizer : OperatorBase { private static int MAX_NUMBER_OF_TRIES = 100; /// public override string Description { get { return "Initializes the value of variable 'Value' to a random value uniformly distributed between 'Min' and 'Max' (exclusive)"; } } /// /// Gets or sets the maximum value of the random number generator (exclusive). /// /// Gets or sets the variable with name Max through the /// method of class . public double Max { get { return ((DoubleData)GetVariable("Max").Value).Data; } set { ((DoubleData)GetVariable("Max").Value).Data = value; } } /// /// Gets or sets the minimum value of the random number generator. /// /// Gets or sets the variable with name Min through the /// method of class . public double Min { get { return ((DoubleData)GetVariable("Min").Value).Data; } set { ((DoubleData)GetVariable("Min").Value).Data = value; } } /// /// Initializes a new instance of with four variable infos /// (Value, Random, Max and Min), being a random number generator /// between 0.0 and 1.0. /// public UniformRandomizer() { AddVariableInfo(new VariableInfo("Value", "The value to manipulate (type is one of: IntData, ConstrainedIntData, DoubleData, ConstrainedDoubleData)", typeof(IObjectData), VariableKind.In)); AddVariableInfo(new VariableInfo("Random", "The random generator to use", typeof(MersenneTwister), VariableKind.In)); AddVariableInfo(new VariableInfo("Min", "Lower bound of the uniform distribution (inclusive)", typeof(DoubleData), VariableKind.None)); GetVariableInfo("Min").Local = true; AddVariable(new Variable("Min", new DoubleData(0.0))); AddVariableInfo(new VariableInfo("Max", "Upper bound of the uniform distribution (exclusive)", typeof(DoubleData), VariableKind.None)); GetVariableInfo("Max").Local = true; AddVariable(new Variable("Max", new DoubleData(1.0))); } /// /// Generates a new uniformly distributed random variable. /// /// The scope where to apply the random number generator. /// null. public override IOperation Apply(IScope scope) { IObjectData value = GetVariableValue("Value", scope, false); MersenneTwister mt = GetVariableValue("Random", scope, true); double min = GetVariableValue("Min", scope, true).Data; double max = GetVariableValue("Max", scope, true).Data; RandomizeUniform(value, mt, min, max); return null; } /// /// Generates a new random number depending on the type of the . /// /// Thrown when an unhandleable type appears. /// The object whose data should be a new randomly generated number. /// The MersenneTwister to generate a new random number. /// The left border of the interval in which the next random number has to lie. /// The right border (exclusive) of the interval in which the next random number /// has to lie. private void RandomizeUniform(IObjectData value, MersenneTwister mt, double min, double max) { // Dispatch manually based on dynamic type, // a bit awkward but necessary until we create a better type hierarchy for numeric types (gkronber 15.11.2008). if (value is DoubleData) RandomizeUniform((DoubleData)value, mt, min, max); else if (value is IntData) RandomizeUniform((IntData)value, mt, min, max); else throw new ArgumentException("Can't handle type " + value.GetType().Name); } /// /// Generates a new double random number. /// /// The double object which the new value is assigned to. /// The random number generator. /// The left border of the interval in which the next random number has to lie. /// The right border (exclusive) of the interval in which the next random number /// has to lie. public void RandomizeUniform(DoubleData data, MersenneTwister mt, double min, double max) { data.Data = mt.NextDouble() * (max - min) + min; } /// /// Generates a new int random number. /// /// The int object which the new value is assigned to. /// The random number generator. /// The left border of the interval in which the next random number has to lie. /// The right border (exclusive) of the interval in which the next random number /// has to lie. public void RandomizeUniform(IntData data, MersenneTwister mt, double min, double max) { data.Data = (int)Math.Floor(mt.NextDouble() * (max - min) + min); } } }