E:/Projects/Visual Studio/CSharp/GEP .NET Framework/GEP.Core/Common/GeneticOperators/GenotypeSelection/RandomAccordingToMatingProabability.cs

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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace GEP.Core.Common.GeneticOperators.GenotypeSelection
{
    [Serializable]
    public class RandomAccordingToMatingProabability : GenotypeSelection
    {
        protected int _selectionSize;
        protected int _n_selections;
        protected int[][] _selection;
        protected int[][][] _allSelections;
        protected int[] _allSelectionsSize;
        protected int[] _allSelectionsStartIndex;
        protected int[] _allSelectionsEndIndex;
        protected int _allSelectionIndex;
        double[] _probabilityDistribution;
        protected Random _random = new Random();

        public RandomAccordingToMatingProabability(int selectionSize, int n_selections, double[] probabilityDistribution)
        {
            _selectionSize = selectionSize;
            _n_selections = n_selections;
            _selection = new int[n_selections][];
            _probabilityDistribution = probabilityDistribution;
            for (int i = 0; i < _n_selections; i++)
            {
                _selection[i] = new int[selectionSize];
            }
            _allSelections = new int[probabilityDistribution.Length + 1][][];
            _allSelectionsSize = new int[_allSelections.Length];
            _allSelectionsStartIndex = new int[_allSelectionsSize.Length];
            _allSelectionsEndIndex = new int[_allSelectionsSize.Length];
            for (int i = _allSelections.Length - 1; 0 <= i; i--)
            {
                _allSelections[i] = _selection;
            }
            _allSelectionIndex = _allSelections.Length;
        }

        public int[][] Select(Population population)
        {
            throw new NotImplementedException();
        }

        public int[][] Select(ref int selectionStartIndex, ref int selectionEndIndex, Population population)
        {
            //Checks if all selections have been iterated.
            if (_allSelectionIndex == _allSelections.Length)
            {
                double rd;
                for (int i = _allSelectionsSize.Length - 1; 0 <= i; i--)
                {
                    _allSelectionsSize[i] = 0;
                }
                bool isLastInProbDistribution;
                for (int i = 0; i < _n_selections; i++)
                {
                    isLastInProbDistribution = true;
                    rd = _random.NextDouble();
                    //picks up according to probability a genetic operator.
                    for (int j = 0; j < _probabilityDistribution.Length; j++)
                    {
                        if (rd < _probabilityDistribution[j])
                        {
                            _allSelectionsSize[j]++;
                            isLastInProbDistribution = false;
                        }
                    }
                    if (isLastInProbDistribution)
                        _allSelectionsSize[_allSelectionsSize.Length - 1]++;
                }
                for (int i = 0, counter = 0; i < _allSelections.Length; i++)
                {
                    _allSelectionsStartIndex[i] = counter;
                    counter += _allSelectionsSize[i];
                    _allSelectionsEndIndex[i] = counter - 1;
                }
                _allSelectionIndex = 0;
            }
            double r;
            double iteratedMatingProb;
            int currentSelectionsEndIndex = _allSelectionsEndIndex[_allSelectionIndex];
            for (int i = _allSelectionsStartIndex[_allSelectionIndex];
                i < currentSelectionsEndIndex; i++)
            {
                iteratedMatingProb = 0;
                for (int j = _allSelections[_allSelectionIndex][i].Length - 1; 0 <= j; j--)
                {
                    r = _random.NextDouble() * population._totalMatingProbability;
                    iteratedMatingProb = 0;
                    for (int k = population.Size - 1; 0 <= k; k--)
                    {
                        iteratedMatingProb += population[k]._matingProbability;
                        if (r < iteratedMatingProb)
                        {
                            _allSelections[_allSelectionIndex][i][j] = k;
                            break;
                        }
                    }
                }
            }
            selectionStartIndex = _allSelectionsStartIndex[_allSelectionIndex];
            selectionEndIndex = _allSelectionsEndIndex[_allSelectionIndex];
            _allSelectionIndex++;
            return _selection;
        }
    }
}

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