/* ------------------------------------------------------------------------- */
int selection(deme *subpop) {
int i, my_rank;
double current_sum = 0.0;
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
long double rand = mt_rand_real(subpop->fit_tot, my_rank);
for (i = 0; i < subpop->pop_size && current_sum <= rand; i++)
current_sum += subpop->old_pop[i]->fitness;
return i-1;
}
static mrb_value mrb_random_mt_rand(mrb_state *mrb, mt_state *t, mrb_value max)
{
mrb_value value;
if (mrb_fixnum(max) == 0) {
value = mrb_float_value(mrb, mt_rand_real(t));
} else {
value = mrb_fixnum_value(mt_rand(t) % mrb_fixnum(max));
}
return value;
}