def update_after_destroy_and_repair_performed(self, destroy: Method, repair: Method, sol_new: Solution,
sol_incumbent: Solution, sol: Solution):
"""Update current solution, incumbent, and all operator score data according to performed destroy+repair.
:param destroy: applied destroy method
:param repair: applied repair method
:param sol_new: obtained new solution
:param sol_incumbent: current incumbent solution
:param sol: current (last accepted) solution
"""
destroy_data = self.score_data[destroy.name]
repair_data = self.score_data[repair.name]
destroy_data.applied += 1
repair_data.applied += 1
score = 0
if sol_new.is_better(sol_incumbent):
score = self.own_settings.mh_alns_sigma1
# print('better than incumbent')
sol_incumbent.copy_from(sol_new)
sol.copy_from(sol_new)
elif sol_new.is_better(sol):
score = self.own_settings.mh_alns_sigma2
# print('better than current')
sol.copy_from(sol_new)
elif sol.is_better(sol_new) and self.metropolis_criterion(sol_new, sol):
score = self.own_settings.mh_alns_sigma3
# print('accepted although worse')
sol.copy_from(sol_new)
elif sol_new != sol:
sol_new.copy_from(sol)
destroy_data.score += score
repair_data.score += score
def metropolis_criterion(self, sol_new: Solution,
sol_current: Solution) -> bool:
"""Apply Metropolis criterion as acceptance decision, return True when sol_new should be accepted."""
if sol_new.is_better(sol_current):
return True
return np.random.random_sample() <= exp(
-abs(sol_new.obj() - sol_current.obj()) / self.temperature)
