double worst(archipelago a, problem::base_ptr original_problem) {
double retval = - boost::numeric::bounds<double>::highest();
for (archipelago::size_type i = 0; i< a.get_size(); ++i) {
// test feasibility
if(original_problem->feasibility_x(a.get_island(i)->get_population().champion().x))
retval = std::max(retval, a.get_island(i)->get_population().champion().f[0]);
}
return retval;
}
double std_dev(archipelago a, double mean, problem::base_ptr original_problem) {
double retval = 0;
for (archipelago::size_type i = 0; i< a.get_size(); ++i) {
// test feasibility
if(original_problem->feasibility_x(a.get_island(i)->get_population().champion().x))
retval += pow((a.get_island(i)->get_population().champion().f[0] - mean),2);
}
return sqrt(retval / a.get_size());
}
double mean(archipelago a, problem::base_ptr original_problem) {
double retval = 0;
int count_feasible_arch = 0;
for (archipelago::size_type i = 0; i< a.get_size(); ++i) {
// test feasibility
if(original_problem->feasibility_x(a.get_island(i)->get_population().champion().x)) {
retval += a.get_island(i)->get_population().champion().f[0];
count_feasible_arch++;
}
}
if(count_feasible_arch != 0)
return retval / count_feasible_arch;
else
return 0.;
}