public class FormulaFitnessFunction
extends org.jgap.gp.GPFitnessFunction
Fitness function for evaluating the produced fomulas, represented as GP
programs. The fitness is computed by calculating the result (Y) of the
function/formula for integer inputs (X's). The sum of the differences
between expected Y and actual Y is the fitness, the lower the better (as
it is a defect rate here).