cs-gene-expression-programming 1.0.3

cs-gene-expression-programming

Gene expression programming implemented using C#

Usage

The sample code belows show how to use the Gene Expression Programming to solve the spiral classification problem:

class Program
{
	static DataTable LoadData(string filename)
	{
		DataTable table = new DataTable();
		table.Columns.Add("X");
		table.Columns.Add("Y");
		table.Columns.Add("Label");

		int line_count = 0;
		using (StreamReader reader = new StreamReader(filename))
		{
			string line = reader.ReadLine();
			int.TryParse(line, out line_count);

			while ((line = reader.ReadLine()) != null)
			{
				string[] elements = line.Split(new char[] { '\t' });

				double x, y;
				int label;
				double.TryParse(elements[0].Trim(), out x);
				double.TryParse(elements[1].Trim(), out y);
				int.TryParse(elements[2].Trim(), out label);

				table.Rows.Add(x, y, label);
			}
		}
		return table;
	}

	static void Main(string[] args)
	{
		DataTable table = LoadData("dataset.txt");

		GEPConfig config = new GEPConfig("GEPConfig.xml");

		GEPPop<GEPSolution> pop = new GEPPop<GEPSolution>(config);

		pop.OperatorSet.AddOperator(new TGPOperator_Plus());
		pop.OperatorSet.AddOperator(new TGPOperator_Minus());
		pop.OperatorSet.AddOperator(new TGPOperator_Division());
		pop.OperatorSet.AddOperator(new TGPOperator_Multiplication());
		pop.OperatorSet.AddOperator(new TGPOperator_Sin());
		pop.OperatorSet.AddOperator(new TGPOperator_Cos());
		pop.OperatorSet.AddIfgtOperator();

		for (int i = 1; i < 10; ++i)
		{
			pop.ConstantSet.AddConstant(string.Format("C{0}", i), i);
		}

		pop.VariableSet.AddVariable("X");
		pop.VariableSet.AddVariable("Y");

		pop.BuildChromosomeBasis();

		pop.CreateFitnessCase += (index) =>
		{
			SpiralFitnessCase fitness_case = new SpiralFitnessCase();
			fitness_case.X = double.Parse(table.Rows[index]["X"].ToString());
			fitness_case.Y = double.Parse(table.Rows[index]["Y"].ToString());
			fitness_case.Label = int.Parse(table.Rows[index]["Label"].ToString());

			return fitness_case;
		};

		pop.GetFitnessCaseCount += () =>
		{
			return table.Rows.Count;
		};

		pop.EvaluateObjectiveForSolution += (fitness_cases, solution, objective_index) =>
		{
			double fitness = 0;
			for (int i = 0; i < fitness_cases.Count; i++)
			{
				SpiralFitnessCase fitness_case = (SpiralFitnessCase)fitness_cases[i];
				int correct_y = fitness_case.Label;
				int computed_y = fitness_case.ComputedLabel;
				fitness += (correct_y == computed_y) ? 0 : 1;
			}

			return fitness;
		};


		pop.BreedInitialPopulation();


		while (!pop.IsTerminated)
		{
			pop.Evolve();
			Console.WriteLine("Spiral Classification Generation: {0}", pop.CurrentGeneration);
			Console.WriteLine("Global Fitness: {0}\tCurrent Fitness: {1}", pop.GlobalBestProgram.Fitness, pop.FindFittestProgramInCurrentGeneration().Fitness);
			Console.WriteLine("Global Best Solution:\n{0}", pop.GlobalBestProgram);
			//Console.WriteLine("Current Best Solution:\n{0}", pop.FindFittestProgramInCurrentGeneration());
		}

		Console.WriteLine(pop.GlobalBestProgram.ToString());
	}
}

The GEPConfig.xml and its child configuration files will be automatically generated if they do not exist, otherwise the configuration will be loaded from the existing GEPConfig.xml and its child configuration files.