// Use the ratio between the minimum and maximum to determine whether the
// population has converged. This method will not work if the values cross
// zero!
// Note that this is significantly different than the definition (and the
// bug-laden implementation) that was in version of GAlib prior to 2.4.5.
//
// For historical purposes, here is the old definition of this method:
//
// Use the ratio of the population mean divided by the population maximum to
// determine whether the population has converged. If we are maximizing, then
// check to see if the ratio exceeds the convergence. If we are minimizing,
// then check to see if the ratio has dropped below the convergence.
GABoolean
GAGeneticAlgorithm::TerminateUponPopConvergence(GAGeneticAlgorithm & ga){
GABoolean val = gaFalse;
if(ga.statistics().current(GAStatistics::Maximum) == 0) {
return val;
}
float ratio =
ga.statistics().current(GAStatistics::Minimum) /
ga.statistics().current(GAStatistics::Maximum);
if(ga.minimaxi() == GAGeneticAlgorithm::MINIMIZE) {
if(ratio <= ga.pConvergence())
val = gaTrue;
else
val = gaFalse;
}
else {
if(ratio >= ga.pConvergence())
val = gaTrue;
else
val = gaFalse;
}
return val;
}
// If we are maximizing, then terminate when the convergence has exceeded the
// specified convergence. If we are minimizing, then terminate when the
// convergence has dropped below the specified convergence.
GABoolean
GAGeneticAlgorithm::TerminateUponConvergence(GAGeneticAlgorithm & ga){
GABoolean val = gaFalse;
if(ga.minimaxi() == GAGeneticAlgorithm::MINIMIZE) {
if(ga.convergence() == 0 || ga.convergence() > ga.pConvergence())
val = gaFalse;
else
val = gaTrue;
}
else {
if(ga.convergence() < ga.pConvergence())
val = gaFalse;
else
val = gaTrue;
}
return val;
}