double fitnessFunction(Solution individual, double[] lambda) {
double fitness;
fitness = 0.0;
if (functionType_.equals("_TCHE1")) {
double maxFun = -1.0e+30;
for (int n = 0; n < problem_.getNumberOfObjectives(); n++) {
double diff = Math.abs(individual.getObjective(n) - z_[n]);
double feval;
if (lambda[n] == 0) {
feval = 0.0001 * diff;
} else {
feval = diff * lambda[n];
}
if (feval > maxFun) {
maxFun = feval;
}
} // for
fitness = maxFun;
} // if
else if (functionType_.equals("_AGG")) {
double sum = 0.0;
for (int n = 0; n < problem_.getNumberOfObjectives(); n++) {
sum += (lambda[n]) * individual.getObjective(n);
}
fitness = sum;
} else if (functionType_.equals("_PBI")) {
double d1, d2, nl;
double theta = 5.0;
d1 = d2 = nl = 0.0;
for (int i = 0; i < problem_.getNumberOfObjectives(); i++) {
d1 += (individual.getObjective(i) - z_[i]) * lambda[i];
nl += Math.pow(lambda[i], 2.0);
}
nl = Math.sqrt(nl);
d1 = Math.abs(d1) / nl;
for (int i = 0; i < problem_.getNumberOfObjectives(); i++) {
d2 += Math.pow((individual.getObjective(i) - z_[i]) - d1 * (lambda[i] / nl), 2.0);
}
d2 = Math.sqrt(d2);
fitness = (d1 + theta * d2);
} else {
System.out.println("MOEAD.fitnessFunction: unknown type " + functionType_);
System.exit(-1);
}
return fitness;
} // fitnessEvaluation
