public Hypothesis Crossover(Hypothesis hypothesisA, Hypothesis hypothesisB)
{
var minLength = Math.Min(hypothesisA.String.Length, hypothesisB.String.Length);
if (minLength == 0)
{
return(hypothesisA.String.Length > hypothesisB.String.Length ? hypothesisA : hypothesisB);
}
var index = Program.MainRandom.Next(0, minLength);
Hypothesis hypA;
Hypothesis hypB;
if (Program.MainRandom.NextDouble() > 0.5)
{
hypA = hypothesisA;
hypB = hypothesisB;
}
else
{
hypA = hypothesisB;
hypB = hypothesisA;
}
var firstPart = hypA.String.Substring(0, index);
var secondPart = hypB.String.Substring(index, hypB.String.Length - index);
var newString = "" + firstPart + secondPart;
var newHypothesis = new Hypothesis {
String = newString
};
return(newHypothesis);
}
public static Hypothesis CreateRandomHypothesis()
{
var newHypotheis = new Hypothesis();
var length = Convert.ToInt32(Program.MainRandom.NextDouble() * (Math.Pow(Program.MainRandom.NextDouble() * 10, (Program.MainRandom.NextDouble() * 3))));
newHypotheis.String = CreateRandomString(length);
return(newHypotheis);
}
private static void MutatePopulation(List <Hypothesis> hypothesisList, double percentToMutate, double mutationIntensity)
{
var populationToMutate = Math.Max(1, Convert.ToInt32(hypothesisList.Count * percentToMutate));
for (var i = 0; i < populationToMutate; i++)
{
var index = Program.MainRandom.Next(0, hypothesisList.Count);
var hypothesisToMutate = hypothesisList[index];
hypothesisList.RemoveAt(index);
hypothesisList.Add(Hypothesis.CreateMutatedHypothesis(hypothesisToMutate, 1 - mutationIntensity));
}
}
private static int ExecuteExperiment(Experiment experiment)
{
//returns milliseconds to get target string
const int timesToTest = 20;
var tests = 0;
//var generationTotal = 0;
var timeTotal = 0;
while (tests < timesToTest)
{
var time = DateTime.Now;
tests++;
var hypothesisList = new List <Hypothesis>();
for (var i = 0; i < experiment.PopulationSize; i++)
{
hypothesisList.Add(Hypothesis.CreateRandomHypothesis());
}
var generations = 0;
while (true)
{
SortAndCull(Program.Comparer, experiment.PopulationSize, experiment.Evaluator, hypothesisList);
var bestHypothesis = hypothesisList.FirstOrDefault();
if (bestHypothesis != null)
{
var bestString = bestHypothesis.String;
if (bestString.Equals(experiment.TargetString))
{
break;
}
}
var newHypothesisList = experiment.CrossoverHandler.CrossoverPopulation(hypothesisList, experiment.PercentToCrossover, experiment.ChildPerPair);
MutatePopulation(newHypothesisList, experiment.PercentToMutate, experiment.MutationIntensity);
hypothesisList.AddRange(newHypothesisList);
generations++;
}
var timeElapsed = (DateTime.Now - time).Milliseconds;
//generationTotal += generations;
timeTotal += timeElapsed;
//Console.WriteLine("Test "+tests+" Found in: " + generations + " generations, "+timeElapsed+" ms");
}
//Console.WriteLine("Average to find the goal over "+timesToTest+" trials: "+(generationTotal/timesToTest)+" generations, "+(timeTotal/timesToTest)+" ms");
//Console.ReadLine();
return(timeTotal / timesToTest);
}
public int EvaluateHypothesis(Hypothesis h)
{
if (h.Evaluated)
{
return(h.Fitness);
}
var fitness = 0;
var minLength = Math.Min(TargetString.Length, h.String.Length);
for (var i = 0; i < minLength; i++)
{
if (h.String[i] == TargetString[i])
{
fitness += 5;
}
}
fitness -= Math.Abs(TargetString.Length - h.String.Length);
h.Evaluated = true;
return(fitness);
}
public static Hypothesis CreateMutatedHypothesis(Hypothesis parent, double mutationIntensity)
{
var newHypothesis = new Hypothesis();
var newString = new string(parent.String.ToCharArray());
while (Program.MainRandom.NextDouble() > mutationIntensity)
{
var index = Program.MainRandom.Next(0, newString.Length);
var type = Program.MainRandom.Next(0, 3);
if (type != 0 && newString.Length > 0)
{
newString = newString.Remove(index, 1);
}
if (type != 1)
{
newString = newString.Insert(index, GetRandomChar());
}
}
newHypothesis.String = newString;
return(newHypothesis);
}
public int EvaluateHypothesis(Hypothesis h)
{
if (h.Evaluated)
{
return(h.Fitness);
}
var fitness = 0;
var minLength = Math.Min(TargetString.Length, h.String.Length);
for (var i = 0; i < minLength; i++)
{
if (h.String[i] == TargetString[i])
{
fitness += 20;
}
else
{
for (var j = 1; j < 3; j++)
{
if (h.String[Math.Min(h.String.Length - 1, i + j)] == TargetString[i])
{
fitness += 10 - j;
break;
}
if (h.String[Math.Max(0, i - j)] != TargetString[i])
{
continue;
}
fitness += 10 - j;
break;
}
}
}
fitness -= Math.Abs(TargetString.Length - h.String.Length) * 2;
h.Evaluated = true;
return(fitness);
}
public int EvaluateHypothesis(Hypothesis h)
{
if (h.Evaluated)
{
return(h.Fitness);
}
var fitness = 10000;
var hIndex = 0;
var endScan = false;
if (h.String.Length > 0)
{
foreach (var charToFind in TargetString)
{
while (h.String[hIndex] != charToFind)
{
hIndex++;
fitness -= 1;
if (hIndex < h.String.Length)
{
continue;
}
endScan = true;
break;
}
if (endScan)
{
break;
}
fitness += 20;
}
}
fitness -= Math.Abs(TargetString.Length - h.String.Length);
h.Evaluated = true;
return(fitness);
}