Patch for /trunk/Sources/Genetic/Fitness Functions/SymbolicRegressionFitness.cs

[GoogleCodeExporter]

Added support for multiple input/feature variables. Previously 
SymbolicRegressionFitness only accepted one input variable and multiple 
constants, now it supports multiple variables and multiple constants. It is 
still backwards compatible, so existing code should not break.

Test code:

    double[] constants = new double[] { 3, 11 };
    int constantCount = constants.Length;

    int exampleCount = 100;
    int featureCount = 3;
    double[,] data = new double[exampleCount, featureCount + 1];

    Random rnd = new Random();
    for (int i = 0; i < exampleCount; i++)
    {
        double x = data[i, 0] = rnd.NextDouble() * 100;
        double y = data[i, 1] = rnd.NextDouble() * 100;
        double z = data[i, 2] = rnd.NextDouble() * 100;
        data[i, 3] = constants[0] * x + constants[1] * x * y + x * y / z;
    }

    Population population = new Population(
        100,
        new GPTreeChromosome(new SimpleGeneFunction(featureCount + constantCount)),
        new SymbolicRegressionFitness(data, constants),
        new EliteSelection()
        );

    do
    {
        population.RunEpoch();
        Console.WriteLine(population.BestChromosome + " -> " + population.BestChromosome.Fitness);
    } while (population.BestChromosome.Fitness < 95);

    Console.ReadLine();

Original issue reported on code.google.com by andre.ch...@gmail.com on 9 May 2013 at 11:04

Attachments:

• SymbolicRegressionFitness.cs.patch