//Binary Bat
public Problem BinaryBat(Problem prob, out double storagePercentage)
{
//default parameters
int populationSize = 3; //number of bats in the population
int subsetSize = 100;
int maxGeneration = 3;
double loudness = 0.5;
double pulseRate = 0.5;
int totalInstances = prob.X.Count(); //problem size
double frequencyMin = 0; //minimum frequency. Frequency range determine the scalings
double frequencyMax = 2; //maximum frequency.
int lowerBound = -2; //set lower bound - lower boundary
int upperBound = 2; //set upper bound - upper boundary
double[] batFitnessVal = new double[populationSize];
double[] newbatFitnessVal = new double[populationSize];
double globalBest = double.MinValue;
ObjectInstanceSelection globalBestBat = null;
Random r = new Random();
FlowerPollinationAlgorithm fpa = new FlowerPollinationAlgorithm();
//initialize population
List <ObjectInstanceSelection> bats = InitializeBinaryBat(populationSize, subsetSize, totalInstances, prob);
List <ObjectInstanceSelection> newBats = new List <ObjectInstanceSelection>(bats.Count); //create a clone of bats
bats.ForEach((item) =>
{
newBats.Add(new ObjectInstanceSelection(item.Attribute_Values, item.Attribute_Values_Continuous, item.Frequency, item.Velocity, item.Pointers, item.Fitness)); //create a clone of flowers
});
batFitnessVal = EvaluateObjectiveFunction(bats, prob); //evaluate fitness value for all the bats
newbatFitnessVal = EvaluateObjectiveFunction(newBats, prob); //evaluate fitness value for new bats. Note: this will be the same for this function call, since pollination has not occur
BatFitness(batFitnessVal, bats); //fitness value for each bats
BatFitness(newbatFitnessVal, newBats); //fitness value for new bats
globalBestBat = EvaluateSolution(batFitnessVal, newbatFitnessVal, globalBest, bats, newBats, globalBestBat, loudness); //get the global best flower
globalBest = globalBestBat.Fitness;
//start bat algorithm
double rand = r.NextDouble(); //generate random number
for (int i = 0; i < maxGeneration; i++)
{
//loop over all bats or solutions
for (int j = 0; j < populationSize; j++)
{
for (int k = 0; k < subsetSize; k++)
{
bats[j].Frequency = frequencyMin + (frequencyMin - frequencyMax) * r.NextDouble(); //Adjust frequency
double randNum = SimpleRNG.GetNormal(); //generate random number with normal distribution
newBats[j].Velocity[k] = newBats[j].Velocity[k] + (bats[j].Attribute_Values[k] - globalBestBat.Attribute_Values[k]) * bats[j].Frequency; //update velocity
//newBats[j].Attribute_Values[k] = fpa.ConvertToBinary(newBats[j].Velocity[k], newBats[j].Attribute_Values[k]); //update bat position in the binary space
newBats[j].Attribute_Values[k] = TransferFunction(newBats[j].Velocity[k], newBats[j].Attribute_Values[k]); //update bat position in the binary space
if (rand > pulseRate)
{
newBats[j].Attribute_Values[k] = globalBestBat.Attribute_Values[k]; //change some of the dimensions of the position vector with some dimension of global best. Refer to reference for more explaination
}
}
}
//Select best solutions from the original population and matured population for the next generation;
fpa.SelectBestSolution(bats, newBats);
//evaluate new solution
newbatFitnessVal = EvaluateObjectiveFunction(newBats, prob); //evaluate fitness value for all the bats
BatFitness(newbatFitnessVal, newBats); //fitness value for new bats
globalBestBat = EvaluateSolution(batFitnessVal, newbatFitnessVal, globalBest, bats, newBats, globalBestBat, loudness); //get the global best flower
globalBest = globalBestBat.Fitness;
//if solution has converged to a optimal user-defined point, stop search
int Max = 60; // maximum percentage reduction
if (globalBest >= Max) //if the percentage reduction has approached 60%, stop search!
{
break;
}
}
//ensure that at least, N instances are selected for classification
int min = 15; //minimum number of selected instances
globalBestBat = fpa.AddInstances(globalBestBat, min);
Problem subBest = fi.buildModelMultiClass(globalBestBat, prob); //build model for the best Instance Mast
storagePercentage = Training.StoragePercentage(subBest, prob); //calculate the percent of the original training set was retained by the reduction algorithm
return(subBest);
}
/// <summary>
/// Evaluate Objective Function
/// </summary>
public double[] EvaluateObjectiveFunction(List <ObjectInstanceSelection> Bats, Problem prob)
{
int NB = Bats.Count; //NF -> number of fireflies
int tNI = Bats.ElementAt(0).Attribute_Values.Count(); //size of each Instance Mask
double[] fitness = new double[NB];
int sum;
List <double> y = new List <double>();
List <Node[]> x = new List <Node[]>();
double C, Gamma;
for (int i = 0; i < NB; i++)
{
//building model for each instance in instance mask in each firefly object
Problem subProb = fi.buildModel(Bats.ElementAt(i), prob);
Parameter param = new Parameter();
if (subProb != null)
{
int countP = subProb.Y.Count(k => k == 1); //counting the total number of positive instance in the subpeoblem
int countN = subProb.Y.Count(k => k == -1); //counting the total number of negative instance in the subproblem
if (countN <= 1 || countP <= 1) //ensuring that there are at least two positive or negative instance in a subproblem
{
int m = 0;
if (countN <= 1)
{
for (int k = 0; k < prob.Count; k++) //if no negative instance, search the whole subproblem and insert two postive instance in the first and second position of subproblem
{
if (prob.Y[k] == -1)
{
subProb.X[m] = prob.X[k]; //insert negative instance in the first and second position
subProb.Y[m] = prob.Y[k]; //insert label
m++;
}
if (m == 2)
{
break;
}
}
}
else if (countP <= 1)
{
for (int k = 0; k < prob.Count; k++) //if no positive instance, search the whole subproblem and insert two postive instance in the first and second position of subproblem
{
if (prob.Y[k] == 1)
{
subProb.X[m] = prob.X[k]; //insert negative instance in the first and second position
subProb.Y[m] = prob.Y[k]; //insert label
m++;
}
if (m == 2)
{
break;
}
}
}
}
Problem subP = Training.ClusteringBoundaryInstance(subProb);
int count = Bats.ElementAt(i).__Attribute_Values.Count(q => q == 1); //total number of selected instances, to be used for subsetSize
double perRedBInstances = (double)(subProb.Count / subP.Count); //percentage reduction for boundary instances
double perRedCuckooInstances = (double)(tNI - count) / tNI; //percentage reduction for cuckoo instances
//fitness[i] = (100 * perRedCuckooInstances);
fitness[i] = (100 * perRedCuckooInstances) + perRedBInstances;
}
}
return(fitness);
}
/// <summary>
/// Performs a Grid parameter selection, trying all possible combinations of the two lists and returning the
/// combination which performed best. Use this method if validation data isn't available, as it will
/// divide the training data and train on a portion of it and test on the rest.
/// </summary>
/// <param name="problem">The training data</param>
/// <param name="parameters">The parameters to use when optimizing</param>
/// <param name="CValues">The set of C values to use</param>
/// <param name="GammaValues">The set of Gamma values to use</param>
/// <param name="outputFile">Output file for the parameter results.</param>
/// <param name="nrfold">The number of times the data should be divided for validation</param>
/// <param name="C">The optimal C value will be placed in this variable</param>
/// <param name="Gamma">The optimal Gamma value will be placed in this variable</param>
public static void Grid(
Problem problem,
Parameter parameters,
List <double> CValues,
List <double> GammaValues,
string outputFile,
int nrfold,
out double C,
out double Gamma)
{
C = 0;
Gamma = 0;
List <double> avgAcc = new List <double>(); //avgAcc->average accuracy; it stores the average accuracies for all the C and Gamma values
List <double> CVal = new List <double>(); //store the C values with high accuracies
List <double> GVal = new List <double>(); //store the C values with high accuracies
double crossValidation = double.MinValue;
StreamWriter output = null;
List <double> nCVal = new List <double>(); //nCVal -> randomly selected new C Values
List <double> nGVal = new List <double>(); //nGVal -> randomly selected new Gamma Values
List <double> nAvgAcc = new List <double>(); //nAvgAcc -> randomly selected new average accuracies
string outputValues = ""; // outputValues -> hold the C,Gamma and accuracy for each iteration. This is for to derive a pattern and formula
//List<string> outputValues = new List<string>(); // outputValues -> hold the C,Gamma and accuracy for each iteration. This is for to derive a pattern and formula
ParameterSelection ps = new ParameterSelection();
FireFly ff = new FireFly();
int nFF = CValues.Count * GammaValues.Count;//nFF -> number of fireflies
Random r = new Random();
int nValues = CValues.Count - 1;
//int nValues = CValues.Count;
if (outputFile != null)
{
output = new StreamWriter(outputFile);
}
//****Firefly Optimized SVM
//for (int i = 0; i < GammaValues.Count; i++)
//{
// parameters.C = CValues[nValues--];
// parameters.Gamma = GammaValues[i];
// double test = Training.PerformCrossValidation(problem, parameters, nrfold);
// //avgAcc.Add(test);
// //CVal.Add(parameters.C);
// //GVal.Add(parameters.Gamma);
// Console.Write("{0} {1} {2}", parameters.C, parameters.Gamma, test);
// outputValues = parameters.C.ToString() + " " + parameters.Gamma.ToString() + " " + test.ToString();
// File.AppendAllText(ps.filePath, outputValues);
// File.AppendAllText(ps.filePath, Environment.NewLine);
// if (output != null)
// output.WriteLine("{0} {1} {2}", parameters.C, parameters.Gamma, test);
// if (test > crossValidation)
// {
// C = parameters.C;
// Gamma = parameters.Gamma;
// crossValidation = test;
// Console.WriteLine(" New Maximum!");
// //break from loop if the cross validation rate is equal to 1 (i.e. 100%)
// /*if (crossValidation == 1.0)
// {
// proceed = true;
// break;
// }*/
// }
// else
// Console.WriteLine();
//}
//Object selectedFirefly = ff.firefly_simple(avgAcc, CVal, GVal, problem, parameters);
//C = (double)selectedFirefly.cValue;
//Gamma = (double)selectedFirefly.GValue;
//Standard SVM Optimization
//for (int i = 0; i < CValues.Count; i++)
// for (int j = 0; j < GammaValues.Count; j++)
// {
// parameters.C = CValues[i];
// parameters.Gamma = GammaValues[j];
// double test = Training.PerformCrossValidation(problem, parameters, nrfold);
// Console.Write("{0} {1} {2}", parameters.C, parameters.Gamma, test);
// if (output != null)
// output.WriteLine("{0} {1} {2}", parameters.C, parameters.Gamma, test);
// if (test > crossValidation)
// {
// C = parameters.C;
// Gamma = parameters.Gamma;
// crossValidation = test;
// Console.WriteLine(" New Maximum!");
// }
// else Console.WriteLine();
// }
for (int i = 0; i < CValues.Count; i++)
{
double test = new double();
for (int j = 0; j < GammaValues.Count; j++)
{
parameters.C = CValues[i];
parameters.Gamma = GammaValues[j];
test = Training.PerformCrossValidation(problem, parameters, nrfold);
File.AppendAllText(ps.filePath2, Environment.NewLine); //insert double line to file at the end of each parameter evaluation
File.AppendAllText(ps.filePath2, Environment.NewLine); //insert double line to file at the end of each parameter evaluation
Console.Write("{0} {1} {2}", parameters.C, parameters.Gamma, test);
outputValues = parameters.C.ToString() + " " + parameters.Gamma.ToString() + " " + test.ToString();
File.AppendAllText(ps.filePath, outputValues);
File.AppendAllText(ps.filePath, Environment.NewLine);
if (output != null)
{
output.WriteLine("{0} {1} {2}", parameters.C, parameters.Gamma, test);
}
if (test > crossValidation)
{
C = parameters.C;
Gamma = parameters.Gamma;
crossValidation = test;
Console.WriteLine(" New Maximum!");
if (test == 1)
{
CVAccuracy = test;
break;
}
else
{
CVAccuracy = test;
}
//outputValues.Add(C.ToString()); outputValues.Add(Gamma.ToString()); outputValues.Add(test.ToString());
//outputValues = C.ToString() + " " + Gamma.ToString() + " " + test.ToString();
//File.AppendAllText(ps.filePath, outputValues);
//File.AppendAllText(ps.filePath, Environment.NewLine);
}
else
{
Console.WriteLine();
}
}
if (test == 1)
{
CVAccuracy = test;
break;
}
else
{
CVAccuracy = test;
}
}
//File.AppendAllText(ps.filePath, Environment.NewLine);
if (output != null)
{
output.Close();
}
}
public Problem SocialSpider(Problem prob, out double storagePercentage)
{
int nSpiders = 5; //population size of spiders
int subsetSize = 100;
int totalInstances = prob.X.Count();;
int bound = 100, maxGen = 5;
double r_a = 1; //This parameter controls the attenuation rate of the vibration intensity over distance
double p_c = 0.7; // p_c describes the probability of changing mask of spider
double p_m = 0.1; // This is also a user-controlled parameter defined in (0, 1). It controls the probability of assigning a one or zero to each bit of a mask
bool info = true;
double[][] globalBestPosition = new double[1][];
double[] targetIntensity = new double[nSpiders]; //best vibration for each spider
//double[] targetPosition = new double[nSpiders]; //target position for each spider
double[,] mask = new double[nSpiders, subsetSize];
double[,] newMask = new double[nSpiders, subsetSize];
double[,] movement = new double[nSpiders, subsetSize];
double[] inactive = new double[nSpiders];
double[] spiderFitnessVal = new double[nSpiders];
double[] newSpiderFitnessVal = new double[nSpiders];
ObjectInstanceSelection globalBestSpider = null;
double globalBest = double.MinValue;
Random rand = new Random();
FlowerPollinationAlgorithm fpa = new FlowerPollinationAlgorithm();
//initialize population
List <ObjectInstanceSelection> spiders = InitializeBinarySpider(nSpiders, subsetSize, totalInstances, prob);
List <ObjectInstanceSelection> newSpiders = new List <ObjectInstanceSelection>(spiders.Count); //create a clone of bats
spiders.ForEach((item) =>
{
newSpiders.Add(new ObjectInstanceSelection(item.Attribute_Values, item.Attribute_Values_Continuous, item.Pointers, item.Fitness, item.Position)); //create a clone of flowers
});
spiderFitnessVal = EvaluateObjectiveFunction(spiders, prob); //evaluate fitness value for all the bats
newSpiderFitnessVal = EvaluateObjectiveFunction(newSpiders, prob); //evaluate fitness value for new spiders. Note: this will be the same for this function call, since pollination has not occur
SpiderFitness(spiderFitnessVal, spiders); //fitness value for each spiders
SpiderFitness(newSpiderFitnessVal, newSpiders); //fitness value for new spider
globalBestSpider = EvaluateSolution(spiderFitnessVal, newSpiderFitnessVal, globalBest, spiders, newSpiders, globalBestSpider); //get the global best spider
globalBest = globalBestSpider.Fitness;
double[] standDev = new double[subsetSize];
List <double> listPositions = new List <double>();
List <double[]> spiderPositions = new List <double[]>();
//calculate the standard deviation of all spider positions
for (int a = 0; a < subsetSize; a++)
{
double[] sPositions = new double[nSpiders];
for (int b = 0; b < nSpiders; b++)
{
sPositions[b] = spiders[b].Attribute_Values[a]; //get all spider positions column wise
//sPositions[b] = spiders[b].Attribute_Values_Continuous[a]; //get all spider positions column wise
}
spiderPositions.Add(sPositions); //save positions in list
}
for (int a = 0; a < subsetSize; a++)
{
standDev[a] = getStandardDeviation(spiderPositions[a].ToList()); //calculate standard deviation for each spider solution
}
double baseDistance = standDev.Average(); //calculate the mean of standev
//compute paired euclidean distances of all vectors in spider; similar to pdist function in matlab. Reference: http://www.mathworks.com/help/stats/pdist.html
int n = (nSpiders * (nSpiders - 1)) / 2; //total number of elements array dist.
double[] euclidenDist = new double[n]; //Note that, this is array for paired eucliden distance, similar to pdist() function in matlab.
int kk = 0;
for (int i = 0; i < nSpiders; i++)
{
for (int j = 1 + i; j < nSpiders; j++)
{
//this distance is in pairs -> 1,0; 2,0; 3,0,...n,0; 2,1; 3,1; 4,1,...n,1;.... It is similar to pdist function in matlab
//euclidenDist[kk++] = computeEuclideanDistance(spiders[j].Attribute_Values_Continuous, spiders[i].Attribute_Values_Continuous); //generate a vibration for each spider position
euclidenDist[kk++] = computeEuclideanDistance(spiders[j].Attribute_Values, spiders[i].Attribute_Values); //generate a vibration for each spider position
//distance[i][j] = computeEuclideanDistance(spiders[i].Attribute_Values, spiders[j].Attribute_Values);
}
}
double[,] distance = SquareForm(euclidenDist, nSpiders); //Convert vibration to square matix, using SquareForm() function in matlab. Reference: see Squareform function in google
//double[,] intensityReceive = new double[nSpiders, nSpiders];
double[][] intensityReceive = new double[nSpiders][];
for (int a = 0; a < maxGen; a++)
{
for (int j = 0; j < nSpiders; j++)
{
//calculate the intensity for all the generated vibrations
intensityReceive[j] = new double[nSpiders];
double A = (spiders[j].Fitness + Math.Exp(-100)) + 1;
double intensitySource = Math.Log(1 / A);
for (int k = 0; k < nSpiders; k++)
{
double intensityAttenuation = Math.Exp(-distance[j, k] / (baseDistance * r_a));
//intensityReceive[j, k] = intensitySource * intensityAttenuation; //intensity for each spider vibration
intensityReceive[j][k] = intensitySource * intensityAttenuation; //intensity for each spider vibration
}
}
//select strongest vibration from intensity
int row = intensityReceive.GetLength(0);
int column = intensityReceive[0].Count();
//IEnumerable<double> bestReceive = Enumerable.Range(0, row).Select(i => Enumerable.Range(0, column).Select(j => intensityReceive[i, j]).Max()); //get the max value in each row
IEnumerable <double> bestReceive = Enumerable.Range(0, row).Select(i => Enumerable.Range(0, column).Select(j => intensityReceive[i][j]).Max()); //get the max value in each row
//IEnumerable<int> bestReceiveIndex = Enumerable.Range(0, row).Select(i => Enumerable.Range(0, column).Select(j => intensityReceive[i, j]).Max()); //get the max value in each row
//get the index of the strongest vibration
int[] maxIndex = new int[nSpiders];
for (int i = 0; i < nSpiders; i++)
{
maxIndex[i] = Array.IndexOf(intensityReceive[i], bestReceive.ElementAt(i));
}
//Store the current best vibration
int[] keepTarget = new int[nSpiders];
int[] keepMask = new int[nSpiders];
double[,] targetPosition = new double[nSpiders, subsetSize];
for (int i = 0; i < nSpiders; i++)
{
if (bestReceive.ElementAt(i) <= targetIntensity[i])
{
keepTarget[i] = 1;
}
inactive[i] = inactive[i] * keepTarget[i] + keepTarget[i];
targetIntensity[i] = (targetIntensity[i] * keepTarget[i]) + bestReceive.ElementAt(i) * (1 - keepTarget[i]);
if (rand.NextDouble() < Math.Pow(p_c, inactive[i]))
{
keepMask[i] = 1;
}
inactive[i] = inactive[i] * keepMask[i];
for (int j = 0; j < subsetSize; j++)
{
//newSpiders[i].Attribute_Values[j] = fi.Binarize(newSpiders[i].Attribute_Values[j] * spiders[maxIndex[i]].Attribute_Values[j] * (1 - keepTarget[i]), rand.NextDouble()); //update solution
targetPosition[i, j] = targetPosition[i, j] * keepTarget[i] + spiders[maxIndex[i]].Attribute_Values[j] * (1 - keepTarget[i]);
//targetPosition[i, j] = targetPosition[i, j] * keepTarget[i] + spiders[maxIndex[i]].Attribute_Values_Continuous[j] * (1 - keepTarget[i]);
newMask[i, j] = Math.Ceiling(rand.NextDouble() + rand.NextDouble() * p_m - 1);
mask[i, j] = keepMask[i] * mask[i, j] + (1 - keepMask[i]) * newMask[i, j]; //update dimension mask of spider
}
}
//Reshuffule the Spider solution
//Method: randomly generated positions pointing to rows and columns in the solution space. With the pointers, we can acess indivdual indices(or positions) in the solution
double[,] randPosition = GenerateRandomSpiderPosition(nSpiders, subsetSize, spiders);
//generate psfo, and perform random walk
double[,] followPosition = new double[nSpiders, subsetSize];
for (int i = 0; i < nSpiders; i++)
{
for (int j = 0; j < subsetSize; j++)
{
followPosition[i, j] = mask[i, j] * randPosition[i, j] + (1 - mask[i, j]) * targetPosition[i, j];
movement[i, j] = rand.NextDouble() * movement[i, j] + (followPosition[i, j] - spiders[i].Attribute_Values[j]) * rand.NextDouble(); //perform random movement
//movement[i, j] = rand.NextDouble() * movement[i, j] + (followPosition[i, j] - spiders[i].Attribute_Values_Continuous[j]) * rand.NextDouble(); //perform random movement
//newSpiders[i].Attribute_Values[j] = fi.Binarize(newSpiders[i].Attribute_Values_Continuous[j] + movement[i, j], rand.NextDouble()); //actual random walk
newSpiders[i].Attribute_Values[j] = fi.Binarize(newSpiders[i].Attribute_Values[j] + movement[i, j], rand.NextDouble()); //actual random walk
}
}
//Select best solutions from the original population and matured population for the next generation;
fpa.SelectBestSolution(spiders, newSpiders);
//evaluate new solution
newSpiderFitnessVal = EvaluateObjectiveFunction(newSpiders, prob); //evaluate fitness value for all the bats
SpiderFitness(newSpiderFitnessVal, newSpiders); //fitness value for new bats
globalBestSpider = EvaluateSolution(spiderFitnessVal, newSpiderFitnessVal, globalBest, spiders, newSpiders, globalBestSpider); //get the global best flower
globalBest = globalBestSpider.Fitness;
//if solution has converged to a optimal user-defined point, stop search
int Max = 60; // maximum percentage reduction
if (globalBest >= Max) //if the percentage reduction has approached 60%, stop search!
{
break;
}
}
//ensure that at least, N instances are selected for classification
int Min = 15; //minimum number of selected instances
globalBestSpider = fpa.AddInstances(globalBestSpider, Min);
Problem subBest = fi.buildModelMultiClass(globalBestSpider, prob); //build model for the best Instance Mast
storagePercentage = Training.StoragePercentage(subBest, prob); //calculate the percent of the original training set was retained by the reduction algorithm
return(subBest);
}
//flower pollination algorithm by Yang
public Problem BinaryFlowerPollination(Problem prob, out double storagePercentage)
{
int nargin = 0, totalInstances = prob.X.Count();
int maxGeneration = 3;
int numOfFlower = 3; //population size
int subsetSize = 100; //dimension for each flower
double probabilitySwitch = 0.8; //assign probability switch
double[] flowerFitnessVal = new double[numOfFlower];
double[] newFlowerFitnessVal = new double[numOfFlower];
double globalBest = double.MinValue;
double newBest = new double();
ObjectInstanceSelection globalBestFlower = null;
int lowerBound = -2; //set lower bound - lower boundary
int upperBound = 2; //set upper bound - upper boundary
int maxIndex;
//inittalize flowers, and get global best
List <ObjectInstanceSelection> flowers = InitializeBinaryFlower(numOfFlower, subsetSize, totalInstances, prob); //initialize solution
List <ObjectInstanceSelection> newFlowers = new List <ObjectInstanceSelection>(flowers.Count); //create a clone of flowers
flowers.ForEach((item) =>
{
newFlowers.Add(new ObjectInstanceSelection(item.__Attribute_Values, item.__Attribute_Values_Continuous, item.__Pointers, item.__Fitness)); //create a clone of flowers
});
flowerFitnessVal = EvaluateObjectiveFunction(flowers, prob); //evaluate fitness value for all the flowers
newFlowerFitnessVal = EvaluateObjectiveFunction(newFlowers, prob); //evaluate fitness value for new flowers. Note: this will be the same for this function call, since pollination has not occur
FlowerFitness(flowerFitnessVal, flowers); //fitness value for each flower
FlowerFitness(newFlowerFitnessVal, newFlowers); //fitness value for new flower
globalBestFlower = EvaluateSolution(flowerFitnessVal, newFlowerFitnessVal, globalBest, flowers, newFlowers, globalBestFlower); //get the global best flower
globalBest = flowerFitnessVal.Max();
//start flower algorithm
Random r = new Random(); int x = 0;
double[] levy = new double[subsetSize];
for (int i = 0; i < maxGeneration; i++)
{
double rand = r.NextDouble();
if (rand > probabilitySwitch) //do global pollination, to produce new pollen solution
{
levy = LevyFlight(subsetSize);
for (int j = 0; j < numOfFlower; j++)
{
for (int k = 0; k < subsetSize; k++)
{
double A = levy[k] * (flowers[j].Attribute_Values[k] - globalBestFlower.Attribute_Values[k]);
double B = flowers[j].Attribute_Values[k] + A; //new pollen solution
//double A = levy[k] * (flowers[j].Attribute_Values_Continuous[k] - globalBestFlower.Attribute_Values_Continuous[k]);
//double B = flowers[j].Attribute_Values_Continuous[k] + A;
newFlowers[j].Attribute_Values[k] = ConvertToBinary(B, r.NextDouble()); //convert to binary
//newFlowers[j].__Attribute_Values[k] = TransferFunction(B, newFlowers[j].__Attribute_Values[k]); //update flower position in the binary space
}
List <int> randNum = Training.GetRandomNumbers(2, numOfFlower); //generate 2 distinct random numbers
for (int k = 0; k < subsetSize; k++)
{
double A = flowers[j].Attribute_Values[k] + (r.NextDouble() * (flowers[randNum[0]].Attribute_Values[k] - flowers[randNum[1]].Attribute_Values[k])); //randomly select two flowers from neighbourhood for pollination
//double A = flowers[j].Attribute_Values_Continuous[k] + r.NextDouble() * (flowers[randNum[0]].Attribute_Values_Continuous[k] - flowers[randNum[1]].Attribute_Values_Continuous[k]); //randomly select two flowers from neighbourhood for pollination
newFlowers[j].Attribute_Values[k] = ConvertToBinary(A, r.NextDouble()); //convert to binary
//newFlowers[j].__Attribute_Values[k] = TransferFunction(A, newFlowers[j].__Attribute_Values[k]); //update flower position in the binary space
}
}
}
else // //do local pollination, to produce new pollen solution
{
for (int j = 0; j < numOfFlower; j++)
{
List <int> randNum = Training.GetRandomNumbers(2, numOfFlower); //generate 2 distinct random numbers
for (int k = 0; k < subsetSize; k++)
{
double A = flowers[j].Attribute_Values[k] + r.NextDouble() * (flowers[randNum[0]].Attribute_Values[k] - flowers[randNum[1]].Attribute_Values[k]); //randomly select two flowers from neighbourhood for pollination
//double A = flowers[j].Attribute_Values_Continuous[k] + r.NextDouble() * (flowers[randNum[0]].Attribute_Values_Continuous[k] - flowers[randNum[1]].Attribute_Values_Continuous[k]); //randomly select two flowers from neighbourhood for pollination
newFlowers[j].Attribute_Values[k] = ConvertToBinary(A, r.NextDouble()); //convert to binary
//newFlowers[j].__Attribute_Values[k] = TransferFunction(A, newFlowers[j].__Attribute_Values[k]); //update flower position in the binary space
}
}
}
//Select best solutions from the original population and matured population for the next generation;
SelectBestSolution(flowers, newFlowers);
//evaluate new solution
newFlowerFitnessVal = EvaluateObjectiveFunction(newFlowers, prob); //evaluate fitness value for all the flowers
FlowerFitness(newFlowerFitnessVal, newFlowers); //fitness value for new flower
globalBestFlower = EvaluateSolution(flowerFitnessVal, newFlowerFitnessVal, globalBest, flowers, newFlowers, globalBestFlower); //Evaluate solution, update better solution and get global best flower
globalBest = globalBestFlower.Fitness;
//if solution has converged to a optimal user-defined point, stop search
int Max = 60; // maximum percentage reduction
if (globalBest >= Max) //if the percentage reduction has approached 60%, stop search!
{
break;
}
}
//ensure that at least, N instances are selected for classification
int min = 15; //minimum number of selected instances
globalBestFlower = AddInstances(globalBestFlower, min);
Problem subBest = fi.buildModelMultiClass(globalBestFlower, prob); //build model for the best Instance Mast
storagePercentage = Training.StoragePercentage(subBest, prob); //calculate the percent of the original training set was retained by the reduction algorithm
return(subBest);
}
//flower pollination algorithm by Yang
public Problem FlowerPollination(Problem prob)
{
int nargin = 0, totalInstances = prob.X.Count(), maxGeneration = 500;
int numOfFlower = 10; //population size
double probabilitySwitch = 0.8; //assign probability switch
int subsetSize = 200; //dimension for each flower
double[] flowerFitnessVal = new double[numOfFlower];
double[] newFlowerFitnessVal = new double[numOfFlower];
FireflyInstanceSelection fw = new FireflyInstanceSelection();
double globalBest = double.MinValue;
double newBest = new double();
ObjectInstanceSelection globalBestFlower = null;
int lowerBound = -2; //set lower bound - lower boundary
int upperBound = 2; //set upper bound - upper boundary
int maxIndex;
//inittalize flowers, and get global best
List <ObjectInstanceSelection> flowers = InitializeFlower(numOfFlower, subsetSize, totalInstances, prob); //initialize solution
List <ObjectInstanceSelection> newFlowers = new List <ObjectInstanceSelection>(flowers.Count); //create a clone of flowers
flowers.ForEach((item) =>
{
newFlowers.Add(new ObjectInstanceSelection(item.__Attribute_Values, item.__Attribute_Values_Continuous, item.__Pointers, item.__Fitness)); //create a clone of flowers
});
flowerFitnessVal = fw.EvaluateObjectiveFunction(flowers, prob); //evaluate fitness value for all the flowers
newFlowerFitnessVal = fw.EvaluateObjectiveFunction(newFlowers, prob); //evaluate fitness value for new flowers. Note: this will be the same for this function call, since pollination has not occur
FlowerFitness(flowerFitnessVal, flowers); //fitness value for each flower
FlowerFitness(newFlowerFitnessVal, newFlowers); //fitness value for new flower
globalBestFlower = EvaluateSolution(flowerFitnessVal, newFlowerFitnessVal, globalBest, flowers, newFlowers, globalBestFlower); //get the global best flower
globalBest = flowerFitnessVal.Max();
//start flower algorithm
Random r = new Random();
double[] levy = new double[subsetSize];
for (int i = 0; i < maxGeneration; i++)
{
double rand = r.NextDouble();
if (rand > probabilitySwitch) //global pollination
{
//global pollination
for (int j = 0; j < numOfFlower; j++)
{
levy = LevyFlight(subsetSize);
for (int k = 0; k < subsetSize; k++)
{
double A = levy[k] * (flowers[j].__Attribute_Values_Continuous[k] - globalBestFlower.__Attribute_Values_Continuous[k]);
double B = flowers[j].__Attribute_Values_Continuous[k] + A;
A = SimpleBounds(B, lowerBound, upperBound); //ensure that value does not go beyond defined boundary
newFlowers[j].__Attribute_Values_Continuous[k] = A;
newFlowers[j].__Attribute_Values[k] = fw.Binarize(B, r.NextDouble()); //convert to binary
}
}
}
else //local pollination
{
for (int j = 0; j < numOfFlower; j++)
{
List <int> randNum = Training.GetRandomNumbers(2, numOfFlower); //generate 2 distinct random numbers
double epsilon = rand;
//local pollination
for (int k = 0; k < subsetSize; k++)
{
double A = flowers[j].__Attribute_Values_Continuous[k] + epsilon * (flowers[randNum[0]].__Attribute_Values_Continuous[k] - flowers[randNum[1]].__Attribute_Values_Continuous[k]); //randomly select two flowers from neighbourhood for pollination
A = SimpleBounds(A, lowerBound, upperBound); //ensure that value does not exceed defined boundary
newFlowers[j].__Attribute_Values_Continuous[k] = A; //save computation
newFlowers[j].__Attribute_Values[k] = fw.Binarize(A, r.NextDouble()); //convert to binary
}
}
}
//evaluate new solution
newFlowerFitnessVal = fw.EvaluateObjectiveFunction(newFlowers, prob); //evaluate fitness value for all the flowers
FlowerFitness(newFlowerFitnessVal, newFlowers); //fitness value for new flower
globalBestFlower = EvaluateSolution(flowerFitnessVal, newFlowerFitnessVal, globalBest, flowers, newFlowers, globalBestFlower); //Evaluate solution, update better solution and get global best flower
globalBest = flowerFitnessVal.Max();
}
//ensure that at least, 40 instances is selected for classification
int countSelected = globalBestFlower.__Attribute_Values.Count(q => q == 1); //count the total number of selected instances
int diff, c = 0, d = 0;
int Min = 40; //minimum number of selected instances
if (countSelected < Min)
{
//if there are less than N, add N instances, where N = the number of selected instances
diff = Min - countSelected;
while (c < diff)
{
if (globalBestFlower.__Attribute_Values[d++] == 1)
{
continue;
}
else
{
globalBestFlower.__Attribute_Values[d++] = 1;
c++;
}
}
}
Problem subBest = fw.buildModel(globalBestFlower, prob); //build model for the best Instance Mast
return(subBest);
}
//compute the k-nearest neighbour of all instances in the dataset
public Problem computeNearestNeighbour(int k, Problem trainDataset, int numOfSubset)
{
double sum = 0; double distance;
int n = trainDataset.Count; //number of data instances
List <Node[]> nearestNeighbours = new List <Node[]>(); List <double> dist = new List <double>(); List <double> labels = new List <double>();
Node[] xNodes = new Node[n];
Node[] yNodes = new Node[n];
object[,] obj = new object[n - 1, 3];
//object[,] obj = new object[k, 3];
object[,] temp = new object[1, 3];
List <Problem> ds = new List <Problem>();
object[,] nn = new object[n, 6]; //data structure containing the NNs and their corresponding distances
double score = 0; //score assigned to individual instance by the oppositiley NNs in its neighbourhood list
object[,] scoreList = new object[n, 3]; //scores assigned to all the instances
object[,] dataSubset = new object[n, 3]; //subset of data to return
//compute distance between Xi and other instances
for (int i = 0; i < n; i++)
{
int ctr = 0; int cntr1 = 0; int cntr2 = 0;
int countP = trainDataset.Y.Count(q => q == 1);
int countN = trainDataset.Y.Count(q => q == -1);
for (int j = 0; j < n; j++)
{
if (j.Equals(i))
{
continue;
}
if (countN <= 1) //come here if we have very few selected negative instance in the subproblem
{
double propP = n * 0.9, propN = n * 0.1;
obj = buildObject(ref ctr, ref cntr1, ref cntr2, i, j, obj, trainDataset, propP, propN); //0.9 and 0.1 are proportion of positive and negative instances to be selected
//ctr++; cntr1++; cntr2++;
}
else if (countP <= 1) //come here if we have very few selected positive instance
{
double propP = n * 0.1, propN = n * 0.9;
obj = buildObject(ref ctr, ref cntr1, ref cntr2, i, j, obj, trainDataset, propP, propN); //0.1 and 0.9 are proportion of positive and negative instances to be selected
}
else if (n > trainDataset.Count) //come here of n is more than the total number of selected instances
{
double propP = countP, propN = trainDataset.Count - countP; //in this case, selected instances consist of all the positive instance and a portion of negative instance
obj = buildObject(ref ctr, ref cntr1, ref cntr2, i, j, obj, trainDataset, propP, propN);
//ctr++; cntr1++; cntr2++;
}
else if (countN < (n * 0.7) || countP < (n * 0.3)) //come here if the selected positive or negative instances is less than the defined proportion
{
if (countP < (n * 0.3))
{
double propP = countP, propN = n - countP; //in this case, selected instances consist of all the positive instance and a portion of negative instance
obj = buildObject(ref ctr, ref cntr1, ref cntr2, i, j, obj, trainDataset, propP, propN);
}
else if (countN < (n * 0.7))
{
double propP = n - countN, propN = countN; //in this case, selected instances consist of all the positive instance and a portion of negative instance
obj = buildObject(ref ctr, ref cntr1, ref cntr2, i, j, obj, trainDataset, propP, propN);
}
}
else //come here if we have fairly good distribution of positive and negative instances
{
double propP = n * 0.3, propN = n * 0.7;
obj = buildObject(ref ctr, ref cntr1, ref cntr2, i, j, obj, trainDataset, propP, propN); //0.3 and 0.7 are proportion of positive and negative instances to be selected
}
}
Training.sortMultiArray(obj); //sort array to select the nearest neighbour of Xi
//select the k-neareast neighbours (using top K elements), their corresponding distances and class labels of Xi
//int subK = 30;
int subK = k;
int count1 = 0; int count2 = 0; int sumN = 0, sumP = 0;
for (int z = 0; z < obj.GetLength(0); z++) //count the total number of positive and negative instances in the subproblem
{
if ((double)obj[z, 2] == 1)
{
sumP++;
}
else
{
sumN++;
}
}
for (int p = 0; p < k; p++) //select k-neareast neighbours (using top K elements), their corresponding distances and class labels of Xi
{
if (count1 < sumP && (double)obj[p, 2] == 1) //NN for positive class
{
dist.Add((double)obj[p, 0]); //distance
nearestNeighbours.Add((Node[])obj[p, 1]); //nearest neighbour i
labels.Add((double)obj[p, 2]); //class labels
count1++;
}
else if (count2 < sumN && (double)obj[p, 2] == -1) // NN for negative class
{
dist.Add((double)obj[p, 0]); //distance
nearestNeighbours.Add((Node[])obj[p, 1]); //nearest neighbour i
labels.Add((double)obj[p, 2]); //class labels
count2++;
}
}
//for (int z = 0; z < obj.Length; z++)
nn[i, 0] = k; nn[i, 1] = dist; nn[i, 2] = nearestNeighbours; nn[i, 3] = trainDataset.X[i]; nn[i, 4] = labels; nn[i, 5] = trainDataset.Y[i];
//Compute Exponential Decay
double EDScore = 0; //Exponential decay score
int counter = 0;
for (int p = 0; p < subK; p++)
{
//compute exponential decay for Xi and all its Nearest neighbour belonging to the opposite class
//if the label of the current instance in the neighbourhood list is not equal to the label of ith instance then compute its Exponential Decay Score
if (((List <double>)nn[i, 4])[p] != (double)nn[i, 5]) //identify the nearest neighbour belonging to the opposite class
{
EDScore += ((List <double>)nn[i, 1])[p] - Math.Pow(((List <double>)nn[i, 1])[p], 2); //compute exponential decay score
counter++; //counting the number of contributors
}
}
EDScore = EDScore / counter;
//determine the scores of every instance
//int numOfContributors = k - counter; //number of NN of opposite class that contributes to Xi
int numOfContributors = counter;
for (int p = 0; p < subK; p++)
{
//if the label of the current instance in the neighbourhood list is not equal to the label of ith instance
if (((List <double>)nn[i, 4])[p] != (double)nn[i, 5])//identify the nearest neighbour belonging to the opposite class
{
score += Math.Exp(-(((List <double>)nn[i, 1])[p] - Math.Pow(((List <double>)nn[i, 1])[p], 2) / EDScore));
}
}
score = score / numOfContributors;
scoreList[i, 0] = score; scoreList[i, 1] = nn[i, 3]; scoreList[i, 2] = nn[i, 5];
dist = new List <double>(); nearestNeighbours = new List <Node[]>(); labels = new List <double>();
//EDScoreList.Add(EDScore);//list of Exponential Decay scores
//Problem pp = new Problem(k, dist, nearestNeighbours, trainDataset.X[i], labels);
//ds.Add(pp);
}
Training.sortMultiArray(scoreList); //sort scores to select the best N instances to be used for training
//select data subset to be used for training. Selected subset are instances that are closest to the data boundary
Node[][] xScoreList = new Node[numOfSubset][];
double[] yScoreList = new double[numOfSubset];
int cnt1 = 0, cnt2 = 0, cnt3 = 0;
int total = n - 1;
for (int i = 0; i < n; i++)
{
for (int j = 0; j < 3; j++)
{
dataSubset[i, j] = scoreList[total, j]; //select instances with the highest scores
}
if (cnt1 < (0.1 * numOfSubset) && (double)dataSubset[i, 2] == 1) //select 70% positive instance of the subset
{
xScoreList[cnt3] = (Node[])dataSubset[i, 1];
yScoreList[cnt3] = (double)dataSubset[i, 2];
cnt1++; cnt3++;
}
else if (cnt2 < (0.9 * numOfSubset) && (double)dataSubset[i, 2] == -1) //select 30% negative instance of the subset
{
xScoreList[cnt3] = (Node[])dataSubset[i, 1];
yScoreList[cnt3] = (double)dataSubset[i, 2];
cnt2++; cnt3++;
}
total--;
}
Problem subset = new Problem(numOfSubset, yScoreList, xScoreList, xScoreList[0].GetLength(0));
return(subset);
}
/// <summary>
/// Main part of the Firefly Algorithm
/// </summary>
//public Problem firefly_simple(List<double> avgAcc, List<double> CValues, List<double> GValues, Problem prob)
public Problem firefly_simple(Problem prob, out double storagePercentage)
{
//int nF = 9; //number of instances
int nI = prob.X.Count(); //total number of instance in dataset
int nFF = 5; //number of fireflies. Note: NFF * subsetsize must not be greater than Size of training dataset
int subsetSize = 100; //size of each firefly Instance Mask
int MaxGeneration = 5; //number of pseudo time steps
int[] range = new int[4] {
-5, 5, -5, 5
}; //range=[xmin xmax ymin ymax]
double alpha = 0.2; //Randomness 0--1 (highly random)
double gamma = 1.0; //Absorption coefficient
int[] xn = new int[subsetSize];
double[] xo = new double[subsetSize];
double[] Lightn = new double[nFF];
double[] Lighto = new double[nFF];
double[] fitnessVal = new double[nFF];
double globalbestIntensity;
ObjectInstanceSelection globalBest = null;
//generating the initial locations of n fireflies
List <ObjectInstanceSelection> fireflies = init_ffa(nFF, subsetSize, nI, prob);
ObjectInstanceSelection[] fireflyBackup = new ObjectInstanceSelection[fireflies.Count];
ObjectInstanceSelection[] fireflyBest = new ObjectInstanceSelection[fireflies.Count];
List <int> changedIndex = new List <int>(); //changedIndex keeps track of the index of fireflies that has been moved
double newBestIntensity = new double();
int maxIndex;
bool stopSearch = false; //stopsearch is will be set to true when the a firefly with classification accuracy = 100 is found.
globalbestIntensity = double.MinValue;
//Iterations or pseudo time marching
for (int i = 0; i < MaxGeneration; i++)
{
//Evaluate objective function
fitnessVal = this.EvaluateObjectiveFunction(fireflies, prob); //evaluate objective function for each firefly
//stop searching if firefly has found the best c and G value that yields 100%
for (int t = 0; t < fitnessVal.Count(); t++)
{
//double predAccr = avgAcc[changedIndex[t]] * 100;
double predAccr = fitnessVal[t] * 100;
if (predAccr == 100) //if prediction accuracy is equal to 100, stop searching and select the firefly that gives this accuracy
{
globalBest = fireflies[changedIndex[t]];
stopSearch = true;
break;
}
}
//stop searching if firefly has found the best c and G value that yields 100%
if (stopSearch == true)
{
break;
}
//fitnessVal = this.EvaluateObjectiveFunction(fireflies, avgAcc, prob); //evaluate objective function for each firefly
newBestIntensity = fitnessVal.Max(); //get the firefly with the highest light intensity
if (newBestIntensity > globalbestIntensity)
{
globalbestIntensity = newBestIntensity;
maxIndex = Array.IndexOf(fitnessVal, newBestIntensity); //select the index for the global best
globalBest = fireflies[maxIndex]; //select the global best firefly
//bestC = (double)fireflies[maxIndex].cValue; //save the C value for the global best
//bestGamma = (double)fireflies[maxIndex].GValue; //save the Gamma for the global best
}
fireflies.CopyTo(fireflyBackup); fitnessVal.CopyTo(Lighto, 0); fitnessVal.CopyTo(Lightn, 0); //creating duplicates
//Lightn.CopyTo(Lighto, 0);
changedIndex.Clear();
ffa_move(Lightn, fireflyBackup, Lighto, alpha, gamma, fireflies, prob);
fireflies.CopyTo(fireflyBackup); //backing up the current positions of the fireflies
Lightn.CopyTo(Lighto, 0); //backing up the current intensities of the fireflies
}
//ensure that at least, 40 instances is selected for classification
int countSelected = globalBest.__Attribute_Values.Count(q => q == 1); //count the total number of selected instances
int diff, c = 0, d = 0;
int Min = 15; //minimum number of selected instances
if (countSelected < Min)
{
diff = Min - countSelected;
//if there are less than 40, add N instances, where N = the number of selected instances and 40
while (c < diff)
{
if (globalBest.__Attribute_Values[d++] == 1)
{
continue;
}
else
{
globalBest.__Attribute_Values[d++] = 1;
c++;
}
}
}
Problem subBest = buildModelMultiClass(globalBest, prob); //model for the best Instance Mast
storagePercentage = Training.StoragePercentage(subBest, prob); //calculate the percent of the original training set was retained by the reduction algorithm
return(subBest);
}
/// <summary>
/// Evaluate Objective Function
/// </summary>
//public double[] EvaluateObjectiveFunction(List<ObjectInstanceSelection> fireflies, List<double> accuracy, Problem prob)
public double[] EvaluateObjectiveFunction(List <ObjectInstanceSelection> fireflies, Problem prob)
{
int NF = fireflies.Count; //NF -> number of fireflies
int tNI = fireflies.ElementAt(0).Attribute_Values.Count(); //size of each Instance Mask
double[] fitness = new double[NF];
int sum;
List <double> y = new List <double>();
List <Node[]> x = new List <Node[]>();
double C, Gamma;
for (int i = 0; i < NF; i++)
{
//building model for each instance in instance mask in each firefly object
Problem subProb = buildModel(fireflies.ElementAt(i), prob);
Parameter param = new Parameter();
if (subProb != null)
{
int countP = subProb.Y.Count(k => k == 1); //counting the total number of positive instance in the subpeoblem
int countN = subProb.Y.Count(k => k == -1); //counting the total number of negative instance in the subproblem
if (countN <= 1 || countP <= 1) //ensuring that there are at least two positive or negative instance in a subproblem
{
int m = 0;
if (countN <= 1)
{
for (int k = 0; k < prob.Count; k++) //if no negative instance, search the whole subproblem and insert two postive instance in the first and second position of subproblem
{
if (prob.Y[k] == -1)
{
subProb.X[m] = prob.X[k]; //insert negative instance in the first and second position
subProb.Y[m] = prob.Y[k]; //insert label
m++;
}
if (m == 2)
{
break;
}
}
}
else if (countP <= 1)
{
for (int k = 0; k < prob.Count; k++) //if no positive instance, search the whole subproblem and insert two postive instance in the first and second position of subproblem
{
if (prob.Y[k] == 1)
{
subProb.X[m] = prob.X[k]; //insert negative instance in the first and second position
subProb.Y[m] = prob.Y[k]; //insert label
m++;
}
if (m == 2)
{
break;
}
}
}
}
Problem subP = Training.ClusteringBoundaryInstance(subProb);
int c = subP.Count;
int count = fireflies.ElementAt(i).__Attribute_Values.Count(q => q == 1); //total number of selected instances, to be used for subsetSize
double percentageReduction = 100 * (tNI - count) / tNI; //calculating percentage reduction for each instance Mask
fitness[i] = percentageReduction;
/*
* ParameterSelection.Grid(subProb, param, "params.txt", out C, out Gamma); //select parameters for each subset
* param.C = C;
* param.Gamma = Gamma;
* Model subModel = Training.Train(subProb, param); //train each subset
* double accr = Prediction.Predict(prob, "ClassificationResults.txt", subModel, false); //use each subset to classify train dataset
* sum = 0;
* for (int j = 0; j < tNI; j++)
* sum += fireflies.ElementAt(i).Attribute_Values[j];
*
* fitness[i] = W_SVM * accr + W_Features * (double)(1 - ((double)sum / (double)tNI)); //fitness evaluation for individual firefly
* //fitness[i] = accuracy[i] + W_Features * (double)(1 - ((double)sum / (double)tNFe)); //fitness evaluation for individual firefly
*/
/*
* for (int j = 0; j < tNI; j++)
* {
* if (fireflies.ElementAt(i).__Attribute_Values[j] == 1) //if instance is selected, use for classification
* {
* int p = fireflies.ElementAt(i).__Pointers[j];
* x.Add(prob.X[p]);
* y.Add(prob.Y[p]);
* }
* else
* continue;
* }
*
* Node[][] X = new Node[x.Count][];
* double[] Y = new double[y.Count];
*
* x.CopyTo(X); //convert from list to double[] array
* y.CopyTo(Y);
*
*
* Problem subProb = new Problem(X.Count(), Y, X, X[0].GetLength(0));
*/
}
}
return(fitness);
}
/// <summary>
/// generating the initial locations of n Cuckoo
/// </summary>
public List <ObjectInstanceSelection> InitializeBinaryCuckoo(int nNests, int subsetSize, int probSize, Problem prob)
{
//Random rnd = new Random();
//List<int> rNum = Training.GetRandomNumbers(probSize, probSize); //generate N random numbers
List <ObjectInstanceSelection> attr_values = new List <ObjectInstanceSelection>();
//int cnt1 = 0, cnt2 = 0, cnt3 = 0;
//create an array of size n for x and y
Random rnd = new Random();
//List<int> rNum = Training.GetRandomNumbers(probSize, probSize); //generate N random numbers
int[] xn = new int[subsetSize]; //instance mask
double[] xn_Con = new double[subsetSize]; //instance mask continuous
//int[] pointers = new int[subsetSize]; //array contain pointer to actual individual instance represented in the instance mask
List <double> classes = fi.getClassLabels(prob.Y); //get the class labels
int nClass = classes.Count;
int div = subsetSize / nClass;
//double freq = new double(); //initialize the frequency of all the bats to zero
//double[] vel = new double[subsetSize]; //initialize the velocity of all the bats to zero
//select pointers to instances for all the particles
//int k = 0;
if (nClass > 2) //do this for multi-class problems
{
int[] pointers = Training.AssignClassPointers_MultipleClass(prob, subsetSize, probSize); //array contain pointer to actual individual instance represented in the instance mask
for (int a = 0; a < nNests; a++)
{
xn = new int[subsetSize]; //instance mask
xn_Con = new double[subsetSize]; //instance mask continuous
for (int j = 0; j < subsetSize; j++)
{
xn[j] = rnd.Next(0, 2);
}
//Training.InstanceMask_MultipleClass(prob, subsetSize, probSize, out xn); //initialize instance mask
ObjectInstanceSelection OI = new ObjectInstanceSelection(xn, xn_Con, pointers, 0.0);
attr_values.Add(OI);
}
}
else //do this for binary class problem
{
int[] pointers = Training.AssignClassPointersBinary(prob, probSize, subsetSize); //array contain pointer to actual individual instance represented in the instance mask
for (int i = 0; i < nNests; i++)
{
xn = new int[subsetSize];
xn_Con = new double[subsetSize];
//pointers = new int[subsetSize];
//cnt1 = 0; cnt2 = 0; cnt3 = 0;
for (int j = 0; j < subsetSize; j++)
{
xn[j] = rnd.Next(0, 2);
}
//Training.InstanceMask_Binary(prob, subsetSize, pointers, out xn);
ObjectInstanceSelection OI = new ObjectInstanceSelection(xn, xn_Con, pointers, 0.0);
attr_values.Add(OI);
//for (int j = 0; j < prob.Count; j++)
//{
// if (cnt1 < (0.7 * subsetSize) && prob.Y[rNum[j]] == -1) //select 70% positive instance of the subset
// {
// xn[cnt3] = rnd.Next(0, 2);
// pointers[cnt3] = rNum[j];
// k++; cnt1++; cnt3++;
// }
// else if (cnt2 < (0.3 * subsetSize) && prob.Y[rNum[j]] == 1)
// {
// xn[cnt3] = rnd.Next(0, 2);
// pointers[cnt3] = rNum[j];
// k++; cnt2++; cnt3++;
// }
// if (cnt3 >= subsetSize)
// break;
//}
}
}
return(attr_values);
}
public Problem CuckooSearch(Problem prob, out double storagePercentage)
{
int nNests = 5; //number of nests, or number of solutions
int subsetSize = 100;
int maxGen = 5; //maximum generation
double discoveryRate = 0.25; //discovery rate of alien eggs
double tolerance = Math.Exp(-5);
int lowerBound = -5;
int upperBound = 5;
int totalInstances = prob.X.Count(); //problem size
double[] cuckooFitnessVal = new double[nNests];
double[] newCuckooFitnessVal = new double[nNests];
ObjectInstanceSelection globalBestCuckoo = null;
double globalBest = double.MinValue;
Random rand = new Random();
FlowerPollinationAlgorithm fpa = new FlowerPollinationAlgorithm();
//initialize population
List <ObjectInstanceSelection> cuckoos = InitializeBinaryCuckoo(nNests, subsetSize, totalInstances, prob);
List <ObjectInstanceSelection> newCuckoos = new List <ObjectInstanceSelection>(cuckoos.Count); //create a clone of bats
cuckoos.ForEach((item) =>
{
newCuckoos.Add(new ObjectInstanceSelection(item.Attribute_Values, item.Attribute_Values_Continuous, item.Pointers, item.Fitness)); //create a clone of flowers
});
cuckooFitnessVal = EvaluateObjectiveFunction(cuckoos, prob); //evaluate fitness value for all the bats
newCuckooFitnessVal = EvaluateObjectiveFunction(newCuckoos, prob); //evaluate fitness value for new bats. Note: this will be the same for this function call, since pollination has not occur
CuckooFitness(cuckooFitnessVal, cuckoos); //fitness value for each bats
CuckooFitness(newCuckooFitnessVal, newCuckoos); //fitness value for new bats
globalBestCuckoo = EvaluateSolution(cuckooFitnessVal, newCuckooFitnessVal, globalBest, cuckoos, newCuckoos, globalBestCuckoo); //get the global best flower
globalBest = globalBestCuckoo.__Fitness;
//generate new solutions
double beta = 3 / 2;
double A = fp.Gamma(1 + beta) * Math.Sin(Math.PI * (beta / 2));
double B = fp.Gamma((1 + beta) / 2) * beta;
double C = (beta - 1) / 2;
double D = Math.Pow(2, C);
double E = A / (B * D);
double sigma = Math.Pow(E, (1 / beta));
double F;
double G;
double step;
double stepSize;
int x = 0;
for (int i = 0; i <= maxGen; i++)
{
for (int j = 0; j < nNests; j++)
{
for (int k = 0; k < subsetSize; k++)
{
F = SimpleRNG.GetNormal() * sigma;
G = SimpleRNG.GetNormal();
step = F / Math.Pow(Math.Abs(G), (1 / beta));
//In the next equation, the difference factor (s-best) means that when the solution is the best solution, it remains unchanged.
//Here the factor 0.01 comes from the fact that L/100 should the typical step size of walks/flights where L is the typical lenghtscale;
//otherwise, Levy flights may become too aggresive/efficient, which makes new solutions (even) jump out side of the design domain (and thus wasting evaluations).
stepSize = 0.01 * step * (cuckoos[j].Attribute_Values[k] - globalBestCuckoo.Attribute_Values[k]);
//Now the actual random walks or levyy flights
newCuckoos[j].Attribute_Values[k] = fi.Binarize((newCuckoos[j].Attribute_Values[k] + stepSize) * SimpleRNG.GetNormal(), rand.NextDouble());
if (cuckoos[j].Attribute_Values[k] == 1 && newCuckoos[j].Attribute_Values[k] == 0)
{
x++;
}
}
}
//discovery and randomization - replace some nest by constructing new solutions
newCuckoos = EmptyNest(cuckoos, newCuckoos, discoveryRate, subsetSize, nNests);
//Select best solutions from the original population and matured population for the next generation;
fpa.SelectBestSolution(cuckoos, newCuckoos);
//evaluate new solution
newCuckooFitnessVal = EvaluateObjectiveFunction(newCuckoos, prob); //evaluate fitness value for all the bats
CuckooFitness(newCuckooFitnessVal, newCuckoos); //fitness value for new bats
globalBestCuckoo = EvaluateSolution(cuckooFitnessVal, newCuckooFitnessVal, globalBest, cuckoos, newCuckoos, globalBestCuckoo); //get the global best flower
globalBest = globalBestCuckoo.Fitness;
//if solution has converged to a optimal user-defined point, stop search
int Max = 60; // maximum percentage reduction
if (globalBest >= Max) //if the percentage reduction has approached 60%, stop search!
{
break;
}
}
//ensure that at least, N instances are selected for classification
int min = 40; //minimum number of selected instances
globalBestCuckoo = fpa.AddInstances(globalBestCuckoo, min);
Problem subBest = fi.buildModelMultiClass(globalBestCuckoo, prob); //build model for the best Instance Mast
storagePercentage = Training.StoragePercentage(subBest, prob); //calculate the percent of the original training set was retained by the reduction algorithm
return(subBest);
}
