/**
* Write report on eveluation to the given stream.
*
* @param a_fitnessFunction p_SupergeneChangeFitnessFunction
* @param a_population Genotype
* @return Chromosome
*/
public IChromosome report(
SupergeneChangeFitnessFunction a_fitnessFunction, Genotype a_population) {
IChromosome bestSolutionSoFar = a_population.getFittestChromosome();
if (!REPORT_ENABLED) {
return bestSolutionSoFar;
}
System.out.println(
"\nThe best solution has a fitness value of " + bestSolutionSoFar.getFitnessValue());
System.out.println("It contained the following: ");
System.out.println(
"\t"
+ a_fitnessFunction.getNumberOfCoinsAtGene(bestSolutionSoFar, QUARTERS)
+ " quarters.");
System.out.println(
"\t" + a_fitnessFunction.getNumberOfCoinsAtGene(bestSolutionSoFar, DIMES) + " dimes.");
System.out.println(
"\t" + a_fitnessFunction.getNumberOfCoinsAtGene(bestSolutionSoFar, NICKELS) + " nickels.");
System.out.println(
"\t" + a_fitnessFunction.getNumberOfCoinsAtGene(bestSolutionSoFar, PENNIES) + " pennies.");
System.out.println(
"For a total of "
+ a_fitnessFunction.amountOfChange(bestSolutionSoFar)
+ " cents in "
+ a_fitnessFunction.getTotalNumberOfCoins(bestSolutionSoFar)
+ " coins.");
return bestSolutionSoFar;
}
/**
* Find and print the solution, return the solution error.
*
* @param a_conf the configuration to use
* @return absolute difference between the required and computed change
*/
protected int solve(
Configuration a_conf,
int a_targetChangeAmount,
SupergeneChangeFitnessFunction a_fitnessFunction,
Gene[] a_sampleGenes)
throws InvalidConfigurationException {
IChromosome sampleChromosome = new Chromosome(a_conf, a_sampleGenes);
a_conf.setSampleChromosome(sampleChromosome);
// Finally, we need to tell the Configuration object how many
// Chromosomes we want in our population. The more Chromosomes,
// the larger number of potential solutions (which is good for
// finding the answer), but the longer it will take to evolve
// the population (which could be seen as bad). We'll just set
// the population size to 500 here.
// ------------------------------------------------------------
a_conf.setPopulationSize(POPULATION_SIZE);
// Create random initial population of Chromosomes.
// ------------------------------------------------
Genotype population = Genotype.randomInitialGenotype(a_conf);
int s;
Evolution:
// Evolve the population, break if the the change solution is found.
// -----------------------------------------------------------------
for (int i = 0; i < MAX_ALLOWED_EVOLUTIONS; i++) {
population.evolve();
s =
Math.abs(
a_fitnessFunction.amountOfChange(population.getFittestChromosome())
- a_targetChangeAmount);
if (s == 0) {
break Evolution;
}
}
// Display the best solution we found.
// -----------------------------------
IChromosome bestSolutionSoFar = report(a_fitnessFunction, population);
return Math.abs(a_fitnessFunction.amountOfChange(bestSolutionSoFar) - a_targetChangeAmount);
}